PS4 GPU is HD7870 confirmed

[freedquaker]

mutantsushi said:

Are HD7870 GPUs all 'perfect' 20 CU units, are are they themseles the results of binning units, selling defects as lower spec'd GPUs, etc?

In any case, that type of comparison is pretty limited because it's just looking at the grossest stats, e.g. # of CUs, texture units, etc.

What is actually unique about PS4's GPU is the ACE, and it actually has the same # as the top of the line R9 290X,

8x ACE * 8 commands per unit = 64 compute command queo vs. (I believe) 16(!!!)  for XBone.

Plenty of areas of a GPU (or CPU) are unused at any given moment, and this GPGPU can take advantage of that,

not to mention GPCPU approaches can in fact fulfill 'traditional graphics' more efficiently than just standard shaders, etc,

e.g. a GPGPU program to cull geometry instead of using shaders to run geometry that doesn't end up getting displayed.

In a way, this is similar to PS3's SPUs (i.e. what gave PS3 the advantage in late games), except it's used how programmers already are using GPGPU on PC.

This is exactly what the PS4 offers as "headroom" for growth/optimization, otherwise it can do the same optimizations that XBone can (but with more CU).

POSSIBLY MAYBE XBone's ESRAM could be used at such high efficiency ratings that the bandwidth might surpass PS4's GDDR5,

but besides that hugely limiting development approaches, the benefit of that will also be limited by XBone's fewer CU.

So the term of reference here should be R9 290X (but with unified GDDR5 memory shared with CPU), not simply HD7870 based on simple CU count.

I do like your analysis here and I am not an expert at the recent GPU technology. My main reason to post this is that it was long speculated that the PS4 GPU was a customized HD7850, but now it is obvious that it is customized HD7870, or something on the same ballpark (so it's technically better than expected). Of course customizations and console specific improvements will unveil much better performance compared to a HD7870 CPU as well, but it's a good reference to begin with.

Another good point is that HD7870 is the ABSOLUTE MINIMUM performance yardstick you can expect from a game. In other words, with no optimization whatsoever, developers can expect at least 20-30% higher performance than on PC. This also means that 90% XB1 exclusives would run equally or better on PS4 without additional optimization whatsoever.

I am loving this generation as it is much more transparent to us, damn it!