{"id":12648,"date":"2009-11-01T07:05:07","date_gmt":"2009-11-01T07:05:07","guid":{"rendered":"http:\/\/alienbabeltech.com\/main\/?p=12648"},"modified":"2011-06-14T04:24:36","modified_gmt":"2011-06-14T03:24:36","slug":"ati-5770-image-quality-analysis","status":"publish","type":"post","link":"http:\/\/alienbabeltech.com\/main\/ati-5770-image-quality-analysis\/","title":{"rendered":"ATi 5000 Series Image Quality Analysis"},"content":{"rendered":"<p><!--pagetitle:Introduction--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Introduction<\/span><\/strong><\/span><\/p>\n<p>This article is part three of a trilogy of articles devoted to the Juniper\/Cypress series. In <a href=\"http:\/\/alienbabeltech.com\/main\/?p=12436\" target=\"_blank\">part one<\/a> I covered performance. <a href=\"http:\/\/alienbabeltech.com\/main\/?p=12474\" target=\"_blank\">Part two<\/a> covered bottlenecking and determined the 5770\u2019s primary limitation <span style=\"color: #99ccff;\">isn\u2019t<\/span> memory bandwidth as many believed.<\/p>\n<p>This article will investigate the 5770\u2019s image quality and focus on anisotropic filtering and super-sampling. The system setup and methodology is exactly the same as in <a href=\"http:\/\/alienbabeltech.com\/main\/?p=12436&amp;page=2\" target=\"_blank\">part one<\/a>.<\/p>\n<p>While the primary purpose of this article is to investigate the 5770\u2019s image quality, the inevitable comparison to nVidia (GTX285) will also be made as required. For a refresher concerning image quality, please see the following articles I\u2019ve written on the subject in the past:<\/p>\n<ul>\n<li><a href=\"http:\/\/alienbabeltech.com\/main\/?p=10638 \" target=\"_blank\">nVidia GT200 series AA investigation<\/a>.<\/li>\n<li><a href=\"http:\/\/alienbabeltech.com\/main\/?p=7429\" target=\"_blank\">ATi 4000 series AA investigation<\/a>.<\/li>\n<li><a href=\"http:\/\/alienbabeltech.com\/main\/?p=3188\" target=\"_blank\">Image quality comparison<\/a>.<\/li>\n<\/ul>\n<p><strong><\/strong><\/p>\n<p>Everything in those articles about ATi\u2019s 2xxx\/3xxx\/4xxx series applies to the 5770, minus any differences covered in this article.<\/p>\n<p><!--pagetitle:Anisotropic Filtering Theory--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Anisotropic Filtering Theory<\/span><\/strong><\/span><\/p>\n<p>I\u2019ll start with anisotropic filtering. In past articles I demonstrated that ATi\u2019s AF was inferior to nVidia\u2019s because it suffered from more aliasing and shimmering. The 5xxx series offers improved AF over ATi\u2019s previous generations, so it\u2019ll be interesting to see how it looks in practice.<\/p>\n<p>The main improvement ATi has brought to the table is angle invariance. This essentially means that all surfaces are filtered with equal strength, regardless of their angle relative to the camera. This improvement could be partly possible due to the removal of the fixed function interpolators that bottlenecked performance and lacked precision, and by moving some of the calculations onto the shaders. Aside from this enhancement, I\u2019m also keen to see if any improvement has been made to surface filtering strength, which is the main area where ATi was visibly weaker than nVidia in the past.<\/p>\n<p>First, here\u2019s AF applied to a theoretical rendering of a tightly textured black and white pattern. These pictures were taken with 16xAF and 8xMSAA (click them to see larger versions).<a href=\"http:\/\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/4850-af.png\"><\/a><\/p>\n<div id=\"attachment_12629\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/4850-af.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12629\" class=\"size-thumbnail wp-image-12629 \" title=\"4850 AF\" src=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/4850-af.png?resize=150%2C150\" alt=\"4850\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12629\" class=\"wp-caption-text\">4850<\/p><\/div> <div id=\"attachment_12628\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/285-af.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12628\" class=\"size-thumbnail wp-image-12628 \" title=\"285 AF\" src=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/285-af.png?resize=150%2C150\" alt=\"285\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12628\" class=\"wp-caption-text\">285<\/p><\/div> <div id=\"attachment_12631\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/5770-af.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12631\" class=\"size-thumbnail wp-image-12631 \" title=\"5770 AF\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/5770-af.png?resize=150%2C150\" alt=\"5770\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12631\" class=\"wp-caption-text\">5770<\/p><\/div>\n<p>We\u2019ll start by paying attention to the colored areas that begin with the red section and move into your screen. This area represents mip-mapping, which is smaller textures derived from the base texture.<\/p>\n<p>With the <span style=\"color: #99ccff;\">4850<\/span> we see the red and green areas are square, while the other colors are clover shaped. This is actually the worst implementation of the three cards, but it was better than current implementations at the time it debuted on ATi&#8217;s X1xxx series.<\/p>\n<p>With the <span style=\"color: #99ccff;\">GTX285<\/span>, we immediately spot the huge improvement over the 4850. The red section is the worst but given it\u2019s octagonal in shape, it\u2019s still much better than the 4850\u2019s box. While the rest of the colors still have a slight flower shape, they\u2019re far closer to being circles than the same 4850 colors are.<\/p>\n<p>With the <span style=\"color: #99ccff;\">5770<\/span>, we see all of the rings are circular without any hint of flower, clover or square shaping. This includes even the tough red section that the other two cards have so much trouble with. Thus the 5xxx is the first board in consumer space to offer truly angle invariant anisotropic filtering at a 16x level.<\/p>\n<p>Next we\u2019ll check filtering strength, and we can do this by ignoring the colored areas and instead focusing on the black\/white\/gray areas in front of them. The star shaped patterns are texture aliasing caused by undersampling. This texture aliasing is responsible for flickering and shimmering on textured surfaces during gaming.<\/p>\n<p>With the <span style=\"color: #99ccff;\">4850<\/span>, we can see more stars appear as we move towards the center, and as we touch the red section, we see multiple adjacent stars. I\u2019ve marked two of them with white arrows.<\/p>\n<p>The <span style=\"color: #99ccff;\">GTX285<\/span> also has the same issue, but as we move further back and touch the red section, the 285\u2019s stars are far less pronounced than the 4850\u2019s. If this were a moving scene, these sections would shimmer less on the GTX285 because the texture filtering is stronger than the 4850.<\/p>\n<p>Moving on to the <span style=\"color: #99ccff;\">5770<\/span>, we see something bizarre happen. It introduces sharp gray transitions of varying texture detail, eventually culminating into what can be called a \u201cdead-zone\u201d \u2013 the solid gray ring touching the outer red section with no discernable texture pattern applied to it. Furthermore, the largest gray ring introduces new stars that the other two cards don\u2019t have (two such instances are marked with white arrows).<\/p>\n<p>While there are no stars in the \u201cdead-zone\u201d &#8211; and hence that area should shimmer less compared to the other cards &#8211; there\u2019s also no obvious texture pattern applied to it either, so this solution isn\u2019t correct. In actual gaming, I\u2019d expect this area to be blurrier than the other cards in comparison.<\/p>\n<p>Based on these results, 5770\u2019s angle invariance is outstanding, but its surface filtering is unacceptably poor and is worse than the other two cards. I can only hope it\u2019s a driver bug that can be fixed.<\/p>\n<p>Incidentally, here\u2019s the same scene with 8xSS on the <span style=\"color: #99ccff;\">5770<\/span>:<\/p>\n<div id=\"attachment_12630\" style=\"width: 160px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/5770-af-8xss.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12630\" class=\"size-thumbnail wp-image-12630 \" title=\"5770 AF 8xSS\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/5770-af-8xss.png?resize=150%2C150\" alt=\"5770 (8xSS)\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12630\" class=\"wp-caption-text\">5770 (8xSS)<\/p><\/div>\n<p>With 8xSS, the surfaces in the gray rings look absolutely superb, and all star patterns are almost invisible. Sadly the sharp transitions are still present however.<\/p>\n<p><!--pagetitle:Anisotropic Filtering Quality--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Anisotropic Filtering Quality<\/span><\/strong><\/span><\/p>\n<p>Now it\u2019s time to compare in-game screenshots, and I\u2019ve chosen <em>Doom 3<\/em> because it\u2019s an excellent test-bed due to its widespread shader, specular and texture aliasing. All of these screenshots are taken at 2560&#215;1600, 16xAF and 8xMSAA. Note however the MSAA level won\u2019t make any difference to the areas we\u2019re looking at because they\u2019re texture and\/or shader aliasing.<\/p>\n<p>Of interest here are the edges of the three vertical stripes inside the door because they\u2019re affected by texture filtering. They sit to the left of the green monitor and are marked with white arrows<\/p>\n<div id=\"attachment_12641\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-4850-af.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12641\" class=\"size-thumbnail wp-image-12641 \" title=\"D3 4850 AF\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-4850-af.png?resize=150%2C150\" alt=\"4850\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12641\" class=\"wp-caption-text\">4850<\/p><\/div> <div id=\"attachment_12639\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-285-af.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12639\" class=\"size-thumbnail wp-image-12639 \" title=\"D3 285 AF\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-285-af.png?resize=150%2C150\" alt=\"285\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12639\" class=\"wp-caption-text\">285<\/p><\/div> <div id=\"attachment_12643\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-5770-af.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12643\" class=\"size-thumbnail wp-image-12643 \" title=\"D3 5770 AF\" src=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-5770-af.png?resize=150%2C150\" alt=\"5770\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12643\" class=\"wp-caption-text\">5770<\/p><\/div>\n<p>The 4850 clearly has the most jagged and wobbly edges of the three cards, especially the left-most line. The 5770 is basically equal to the GTX285, and this is a definite improvement that will be noticeable in-game during movement.<\/p>\n<p>Now here\u2019s another example that contains text:<\/p>\n<div id=\"attachment_12640\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-4850-af2.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12640\" class=\"size-thumbnail wp-image-12640 \" title=\"D3 4850 AF2\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-4850-af2.png?resize=150%2C150\" alt=\"4850\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12640\" class=\"wp-caption-text\">4850<\/p><\/div> <div id=\"attachment_12638\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-285-af2.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12638\" class=\"size-thumbnail wp-image-12638 \" title=\"D3 285 AF2\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-285-af2.png?resize=150%2C150\" alt=\"285\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12638\" class=\"wp-caption-text\">285<\/p><\/div> <div id=\"attachment_12642\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-5770-af2.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12642\" class=\"size-thumbnail wp-image-12642 \" title=\"D3 5770 AF2\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-5770-af2.png?resize=150%2C150\" alt=\"5770\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12642\" class=\"wp-caption-text\">5770<\/p><\/div>\n<p>The GTX285 has the sharpest text of the three, while the 4850 looks a tad blurrier, especially with the word \u201coperations\u201d. This is probably the angle of the text causing the difference with respect to ATi\u2019s box filtering angles. The 5770 in contrast has much blurrier text than either card. This isn\u2019t caused by the angle since we know the card\u2019s AF is angle invariant, so my theory about the earlier \u201cdead-zone\u201d transfers into gaming to some degree.<\/p>\n<p>My hypothesis is that in order to match nVidia\u2019s lower levels of texture aliasing, ATi does it at the expense of texture clarity. This is similar to what we saw in the theoretical render, where the gray \u201cdead-zone\u201d didn\u2019t have the same detail level on the 5770 as it did on the 4850\/285.<\/p>\n<p>So subjectively the 5770 will look better than the 4850 because it\u2019ll have less aliasing, but some parts will be blurrier too. Overall nVidia\u2019s filtering is still superior because it offers the sharpest text while being tied for the smoothest door at the same time. Remember, the goal of anisotropic filtering is to <span style=\"color: #99ccff;\">sharpen<\/span> textures <span style=\"color: #99ccff;\">without<\/span> introducing additional texture aliasing.<\/p>\n<p><!--pagetitle:Super-Sampling History--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Super-Sampling History<\/span><\/strong><\/span><\/p>\n<p>From my past articles you know that super-sampling has the unique property of being able to anti-alias everything on the screen, including shaders and textures which edge methods such as MSAA can\u2019t touch.<\/p>\n<p>Super-sampling has been available on nVidia\u2019s cards since the original GeForce, and is unofficially available on all current parts. nVidia\u2019s method is oversampling \u2013 rendering the image bigger then scaling down \u2013 so it generates an ordered grid pattern. This method has been unchanged on their single cards, though later cards combined the super-sampling component with varying levels of multi-sampling.<\/p>\n<p>The disadvantage of this method is that the improved image quality is very poor relative to the sample count and workload required to generate it, and it\u2019s particularly poor on (near) horizontal and (near) vertical edges. The advantage is that it automatically improves the LOD so it stacks with anisotropic filtering, thereby increasing texture clarity on filtered surfaces.<\/p>\n<p>Like nVidia, ATi also had ordered grid super-sampling on the original Radeon, but this was vastly improved on the Radeon 8500. The 8500 employed a master sparse-sampled grid with eight fixed locations, but actual samples were a randomly picked subset of them, and varied across different blocks of pixels. This is arguably the finest AA implementation ever seen in consumer space because it\u2019s pseudo stochastic, meaning different parts of the scene have different AA patterns applied to them. The R300 then dropped super-sampling and moved to multi-sampling.<\/p>\n<p><!--pagetitle:ATi's Super-Sampling--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">ATi&#8217;s Super-Sampling<\/span><\/strong><\/span><\/p>\n<p>Super-sampling returns with the 5xxx series, and the method ATi has chosen is actually closest to 3dfx\u2019s approach than others\u2019. Both vendors render the same scene multiple times with a slight offset and combine the samples together. The main difference is that 3dfx shifts the position of the geometry, while ATi shifts the position of each sample. Like 3dfx, ATi has a 4x rotated grid and an 8x sparse grid, but 8x was only available on the unreleased Voodoo 5 6000.<\/p>\n<p>The advantage of this method is that rotated and sparse girds are easily viable, and provide superior anti-aliasing to ordered grids with equal sample counts, especially at (near) vertical and (near) horizontal edges. The disadvantage of this method is that the LOD isn\u2019t automatically improved and has to be controlled properly, otherwise scene blurring may occur.<\/p>\n<p>I\u2019d recommend a LOD bias of <span style=\"color: #99ccff;\">-0.5<\/span> for each AA level (so <span style=\"color: #99ccff;\">-0.5<\/span> for <span style=\"color: #99ccff;\">2xSS<\/span>, <span style=\"color: #99ccff;\">-1.0<\/span> for <span style=\"color: #99ccff;\">4xSS<\/span>, and <span style=\"color: #99ccff;\">-1.5<\/span> for <span style=\"color: #99ccff;\">8xSS<\/span>). You may subjectively prefer a sharper image and use smaller values, but don\u2019t go overboard. There\u2019s more to image quality than just sharpness, and an excessively low LOD bias will introduce additional texture aliasing which defeats the purpose of super-sampling in the first place. You can control the LOD bias with a tool such as ATi Tray Tools if you can get it to work with your 5xxx. I couldn\u2019t at the time of this writing, but there was a new version released just as I was ready to publish the article.<\/p>\n<p>Note that super-sampling only functions in DX9 (or lower), and in OpenGL; it won\u2019t currently function in DX10\/DX11. This is likely because DX10\/11 provides developers with extra tools to control anti-aliasing more, such as the ability to run shaders at sample frequency rather than pixel frequency, effectively allowing shaders to selectively anti-alias themselves.<\/p>\n<p>Here are the sample patterns for ATI\u2019s three super-sampling modes:<\/p>\n<p style=\"TEXT-ALIGN: center\"> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12647\" title=\"Grids\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/grids.png?resize=383%2C168\" alt=\"Grids\" srcset=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/grids.png?resize=383%2C168 383w, http:\/\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/grids-300x131.png 300w\" sizes=\"auto, (max-width: 383px) 100vw, 383px\" data-recalc-dims=\"1\" \/><\/p>\n<p>If these patterns look familiar, it\u2019s because their sample positions are exactly the same as MSAA, except all of them are texture\/shader samples. Thus when SSSA is in operation, it operates in lock-step with the base multi-sampling pattern. Or to put it another way, when super-sampling is activated, all multi-samples become super-samples. As mentioned before, this is done by rendering the image multiple times, so 8xSS renders the image eight times and averages eight samples for each final pixel.<\/p>\n<p><!--pagetitle:Super-Sampling Quality--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Super-Sampling Quality<\/span><\/strong><\/span><\/p>\n<p>I\u2019ll continue using <em>Doom 3<\/em>, but this time I\u2019ll use a tiled floor afflicted by specular aliasing generated by the lighting shader.<\/p>\n<div id=\"attachment_12637\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-16xs.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12637\" class=\"size-thumbnail wp-image-12637 \" title=\"D3 16xS\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-16xs.png?resize=150%2C150\" alt=\"285 (16xS)\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12637\" class=\"wp-caption-text\">285 (16xS)<\/p><\/div> <div id=\"attachment_12634\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-2xss.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12634\" class=\"size-thumbnail wp-image-12634 \" title=\"D3 2xSS\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-2xss.png?resize=150%2C150\" alt=\"5770 (2xSS)\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12634\" class=\"wp-caption-text\">5770 (2xSS)<\/p><\/div> <div id=\"attachment_12635\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-4xss.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12635\" class=\"size-thumbnail wp-image-12635 \" title=\"D3 4xSS\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-4xss.png?resize=150%2C150\" alt=\"5770 (4xSS)\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12635\" class=\"wp-caption-text\">5770 (4xSS)<\/p><\/div>\n<div id=\"attachment_12636\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-8xss.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12636\" class=\"size-thumbnail wp-image-12636 \" title=\"D3 8xSS\" src=\"http:\/\/i2.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/d3-8xss.png?resize=150%2C150\" alt=\"5770 (8xSS)\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12636\" class=\"wp-caption-text\">5770 (8xSS)<\/p><\/div>\n<p>On the GTX285 I used <span style=\"color: #99ccff;\">16xS<\/span>, which contains 4x ordered grid super-sampling. With this the floor is improved over regular AF, but aliasing is still clearly visible. In particular, we still have widespread \u201cbows\u201d in the third horizontal section marked by white arrows.<\/p>\n<p>With <span style=\"color: #99ccff;\">2xSS<\/span> on the 5770, you can see the results are vastly superior to 16xS, despite taking only half the super-samples. This is what I meant earlier when I said ordered grid wasn\u2019t cost-effective relative to the quality it produces. We still have slight bow patterns in the two closest horizontal sections however, marked by white arrows.<\/p>\n<p>With <span style=\"color: #99ccff;\">4xSS<\/span>, all of the bow patterns are gone, and we attain almost perfect image quality.<\/p>\n<p><span style=\"color: #99ccff;\">8xSS<\/span> achieves a small quality improvement in the middle and closest horizontal sections. You can also see that even 8xSS doesn\u2019t have discernable blurring, despite no LOD adjustment. This is what super-sampling looks like when it works properly.<\/p>\n<p>Also if you look carefully in all of the 5770 pictures, you can see two borders running horizontally that very slightly mark transitions of varying texture detail. This is probably caused by the same issue that caused the sharp gray transitions earlier, and I\u2019ve marked the 8xSS picture with white arrows to show them. It\u2019s tough to see them in still screenshots, but they\u2019re more apparent during movement.<\/p>\n<p><!--pagetitle:Super-Sampling Problems--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Super-Sampling Problems<\/span><\/strong><\/span><\/p>\n<p>Here\u2019s an example of excessive blurring on the 5770. This is <em>Call of Duty 4<\/em> running 2xSS compared to 2xMSAA, and in-game it looks like everything is experiencing a massive blur filter.<\/p>\n<div id=\"attachment_12632\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/cod4-2x.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12632\" class=\"size-thumbnail wp-image-12632 \" title=\"CoD4 2x\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/cod4-2x.png?resize=150%2C150\" alt=\"2x\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12632\" class=\"wp-caption-text\">2x<\/p><\/div> <div id=\"attachment_12633\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/cod4-2xss.png\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-12633\" class=\"size-thumbnail wp-image-12633 \" title=\"CoD4 2xSS\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/cod4-2xss.png?resize=150%2C150\" alt=\"2xSS\" data-recalc-dims=\"1\" \/><\/a><p id=\"caption-attachment-12633\" class=\"wp-caption-text\">2xSS<\/p><\/div>\n<p>Even with 8xSS and no LOD adjustment, <em>Doom 3<\/em> had no discernable blurring, so this blurring is clearly abnormal. I\u2019ve personally seen it in <em>Call of Duty 4<\/em>, <em>Wolfenstein<\/em>, and <em>Quake Wars<\/em>, and it makes any level of super-sampling completely unusable in those games.<\/p>\n<p><!--pagetitle:1680x1050--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">1680&#215;1050<\/span><\/strong><\/span><\/p>\n<p>Now it\u2019s time test the performance of the different AA modes. I was unable to test the games I wanted because the current drivers for the 5770 are quite problematic in some games. They often ignore settings from the control panel, and also deliver inconsistent and unexpected performance in a lot of situations. In the end most titles ended up being OpenGL because their results were consistently reliable and well-behaved.<\/p>\n<p>When looking at the results, remember that the relative performance hit of the AA modes compared to each other is more important than the actual numbers. To make it easier to digest the information, I\u2019ve color coded the results into groups based on AA type. <span style=\"color: #ffcc99;\">MS<\/span> = multi-sampling, <span style=\"color: #ffff99;\">CF<\/span> = custom filter sampling (edge detect), while <span style=\"color: #ccffcc;\">SS<\/span> represents super-sampling.<\/p>\n<p style=\"TEXT-ALIGN: center\"> <a href=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1680.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12644\" title=\"Graph 1680\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1680.png?resize=545%2C845\" alt=\"Graph 1680\" srcset=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1680.png?resize=545%2C845 545w, http:\/\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1680-193x300.png 193w\" sizes=\"auto, (max-width: 545px) 100vw, 545px\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>In <em>Call of Duty 4<\/em> and <em>Wolfenstein<\/em>, 2xSS sits between 12xAA and 24xAA in terms of performance, and 4xSS\/8xSS are the slowest performing AA modes.<\/p>\n<p>Super-sampling on the 5770 fares much better in <em>Far Cry 2<\/em>, with 2xSS being almost as fast as 4xMSAA, and 4xSS being almost as fast as 12xAA. The 5770 demonstrated impressive performance in this game, and it appears to carry over to the other AA modes too. I had thought perhaps AA wasn\u2019t being applied, but clearly the staggered benchmarks (and in-game IQ differences) confirm that isn\u2019t the case.<\/p>\n<p><!--pagetitle:1920x1200--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">1920&#215;1200<\/span><\/strong><\/span><\/p>\n<p style=\"TEXT-ALIGN: center\"> <a href=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1920.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12645\" title=\"Graph 1920\" src=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1920.png?resize=544%2C578\" alt=\"Graph 1920\" srcset=\"http:\/\/i0.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1920.png?resize=544%2C578 544w, http:\/\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-1920-282x300.png 282w\" sizes=\"auto, (max-width: 544px) 100vw, 544px\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>OpenGL performance seems to be a strong point for ATi lately, especially in Doom 3 engine games like these two, and it really shows here.<\/p>\n<p>In <em>Quake 4<\/em> we see blazing performance with 2xSS, which turns in a faster score than 4xMSAA. We also see 4xSS is faster than 8xMSAA. Delivering over 60 FPS at 1920&#215;1200 while rendering each frame four times is amazing, considering the card only has a 128 bit memory bus with slightly more bandwidth than a 4850.<\/p>\n<p>This is what I meant when I said the drivers deliver inconsistent performance. When they\u2019re optimal, the 5770 flies through my benchmarks like a rocket. When they\u2019re not, performance is abysmal and horribly erratic.<\/p>\n<p>Performance is a little weaker in <em>Quake Wars<\/em>, but we still get over 50 FPS with 2xSS at 1920&#215;1200, which is respectable.<\/p>\n<p><!--pagetitle:2560x1600--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">2560&#215;1600<\/span><\/strong><\/span><\/p>\n<p style=\"TEXT-ALIGN: center\"> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12646\" title=\"Graph 2560\" src=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-2560.png?resize=545%2C588\" alt=\"Graph 2560\" srcset=\"http:\/\/i1.wp.com\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-2560.png?resize=545%2C588 545w, http:\/\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/graph-2560-278x300.png 278w\" sizes=\"auto, (max-width: 545px) 100vw, 545px\" data-recalc-dims=\"1\" \/><\/p>\n<p>I deliberately picked <em>Doom 3<\/em> because like <em>Far Cry 2<\/em> and <em>Quake 4<\/em>, the 5770 delivers exceptional performance in it. And it carries over here too, with both 2xSS and 4xSS generating impressive results for a 128 bit card at 2560&#215;1600. With double the execution resources and bandwidth, the bigger 5870 could even make 8xSS viable where it isn\u2019t on the 5770.<\/p>\n<p><em>Prey<\/em> runs much slower, but it\u2019s also a lot more demanding than <em>Doom 3<\/em>, so the 2xSS score at 2560&#215;1600 is still quite respectable for a 5770.<\/p>\n<p><span style=\"color: #99ccff;\"><strong> <\/strong><\/span><\/p>\n<p><!--pagetitle:Conclusion--><!--nextpage--><span style=\"color: #99ccff;\"><strong><span style=\"text-decoration: underline;\">Conclusion<\/span><\/strong><\/span><\/p>\n<p>With regards to anisotropic filtering, the 5770 delivers a mixed bag. Its angle invariance filters more angles than any other board previously did, but the transitions of varying filtering detail &#8211; and unexplainable loss of detail &#8211; means a step backward from previous offerings. These issues visibly flared up in the theoretical test, but were much less visible in <em>Doom 3<\/em>. But again I\u2019ll repeat they could simply be bugs as a consequence of moving certain calculations to the shaders and, if fixed, we could be looking at the finest AF ever seen in consumer space. It\u2019ll be interesting to see how this situation pans out.<\/p>\n<p>Subjectively the card\u2019s AF looks better than previous ATi generations like the 4xxx series because it shimmers far less in-game, but nVidia still has superior AF overall.<\/p>\n<p>As for super-sampling, when it works properly, it looks absolutely stunning (e.g. <em>Doom 3<\/em>, <em>Quake 4<\/em>, and <em>Call of Duty 1<\/em>). It also exhibits little to no blurring, even at 8xSS without a LOD adjustment. I\u2019ve never seen the aforementioned games looking as great as they look on a 5770. Even 2xSS visibly clears up <em>Doom 3<\/em> to the point that most surfaces sit perfectly still, yet the mode is far faster than nVidia\u2019s 8xS.<\/p>\n<p>Unfortunately super-sampling performance is subpar and inconsistent in many games due to suboptimal drivers, and there are also issues with forcing it from the control panel. Also some games have excessive blurring even with 2xSS, so it exhibits unusably poor image quality. ATi needs to address these issues and also implement a LOD slider into their control panel, assuming they don\u2019t plan on automatically adjusting it behind the scenes, that is.<\/p>\n<p>Super-sampling has a lot of potential, but it\u2019s far too raw at this moment to be considered a general working solution.<\/p>\n<p><strong><\/strong><\/p>\n<blockquote>\n<p><span style=\"color: #99ccff;\">Please join us in our <a href=\"http:\/\/alienbabeltech.com\/abt\/index.php\" target=\"_blank\">Forums<\/a><\/span><\/p>\n<p><span style=\"color: #99ccff;\">Follow us on <a href=\"http:\/\/twitter.com\/alienbabeltech\" onclick=\"_gaq.push(['_trackEvent', 'outbound-article', 'http:\/\/twitter.com\/alienbabeltech', 'Twitter']);\" target=\"_blank\">Twitter<\/a><\/span><\/p>\n<p><span style=\"color: #99ccff;\">For the latest updates from ABT, please <a href=\"http:\/\/alienbabeltech.com\/main\/?feed=rss2\" target=\"_blank\">join our RSS News Feed<\/a><\/span><\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p><a href=\"http:\/\/alienbabeltech.com\/main\/?p=12648\"><img decoding=\"async\" align=top title=\"Author: BFG10K\" src=\"http:\/\/alienbabeltech.com\/main\/wp-content\/uploads\/2009\/11\/Article-Image.PNG\"><\/a><\/p>\n","protected":false},"author":5,"featured_media":16748,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7814,7],"tags":[2528,271,73,2577,258,2597,2576,275,273,2596],"class_list":["post-12648","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-articles","category-technology","tag-2528","tag-anisotropic-filtering","tag-ati","tag-blurring","tag-image-quality","tag-lod","tag-shimmering","tag-super-sampling","tag-texture-aliasing","tag-texture-filtering"],"_links":{"self":[{"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/posts\/12648","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/comments?post=12648"}],"version-history":[{"count":0,"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/posts\/12648\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/media\/16748"}],"wp:attachment":[{"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/media?parent=12648"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/categories?post=12648"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/alienbabeltech.com\/main\/wp-json\/wp\/v2\/tags?post=12648"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}