07-23-2020, 08:00 AM
https://www.extremetech.com/gaming/31300...-navi-gpus
Quote:There are rumors going around that Big Navi might dramatically faster than expected, with performance estimated at 1.95x – 2.25x higher than the 5700 XT. This would be an astonishing feat, to put it mildly. The slideshow below shows our test results from the 5700 XT and 5700. The 5700 XT matched the RTX 2070 (and sometimes the 2080) well, while the 5700 was modestly faster than the RTX 2060 for a slightly higher price. A 1.95 – 2.25x speed improvement would catapult Big Navi into playable frame rates even on the most demanding settings we test; 18fps in Metro Exodus at Extreme Detail and 4K becomes 35-41 fps depending on which multiplier you choose. I have no idea how Big Navi would compare against Ampere at that point, but it would handily blow past the RTX 2080 Ti.
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I haven’t addressed the question of IPC at all, but I want to touch on it here. When Nvidia launched Turing, it paid a significant penalty in die size and power consumption relative to a GPU with an equivalent number of cores, TMUs, and ROPs but without the tensor cores and RT cores. What does that mean for AMD? I don’t know.
The Nvidia and AMD / ATI GPUs of any given generation almost always prove to respond differently to certain types of workloads in at least a few significant ways. In 2007, I wrote an article for Ars Technica that mentioned how the 3DMark pixel shader test could cause Nvidia power consumption to surge.
I later found a different 3DMark test (I can’t recall which one, and it may have been in a different version of the application) that caused AMD’s power consumption to similarly surge far past Nvidia.
Sometimes, AMD and Nvidia implement more-or-less the same solution to a problem. Sometimes they build GPUs with fundamental capabilities (like asynchronous computing or ray tracing) that their competitor doesn’t support yet. It’s possible that AMD’s implementation of ray tracing in RDNA2 will look similar to Nvidia’s in terms of complexity and power consumption penalty. It’s also possible that it’ll more closely resemble whatever Nvidia debuts with Ampere, or be AMD’s unique take on how to approach the ray tracing efficiency problem.
The point is, we don’t know. It’s possible that RDNA’s improvements over RDNA1 consist of much better power efficiency, higher clocks, more CUs, and ray tracing as opposed to any further IPC gains. It’s also possible AMD has another IPC jump in store.
The tea leaves and indirect rumors from sources suggest, at minimum, that RDNA2 should sweep past the RTX 2000 family in terms of both power efficiency and performance. I don’t want to speculate on exactly what those gains or efficiencies will be or where they’ll come from, but current scuttlebutt is that it’ll be a competitive high-end battle between AMD and Nvidia this time around. I hope so, if only because we haven’t seen the two companies truly go toe-to-toe at the highest end of the market since ~2013.