The battle of the HTPC cards, Galaxy’s GT 520 vs. HD 6450 (GDDR5 vs. GDDR3)

GDDR5 vs DDR3

This was interesting. Our intention was to try and show performance scaling by matching the core speeds of the GDDR5 and DDR3 versions of the HD 6450 to each other. At the same time, we lowered the vRAM clocks of the GDDR5 version and raised the DDR3 clocks until we had a momentary parity with only one benchmark – 3DMark11 (with the ambient temperatures in the 60sF we achieved a solid run once). Check out the following charts.

Of course these are “scores” but they are very regular and related to the core and/or memory speed changes. Let’s look at the framerates of the mini-games.

We see the same regularity as with the scores. Now let’s look at Far Cry 2 which has a very detailed and accurate benchmark. We tested at 1680×1050, no AA and with ultra settings.

We can see by raising the core speed, we get a framerate boost. We also note a solid boost with the RAM speed increase (and performance decrease with the RAM and clockspeed decrease of the GDDR5 card). Let’s check out 3DMark11 and the only run that completed with our HIS HD 6450 at 725/900(x2)MHz effectively matching the GDDR5 version at 725/450(x4)MHz.

And now the framerates.

From these quick tests, we can see that GDDR5 is a luxury for a card of this class but essential for higher clocked cards.