Discussion Playstation 6 speculation

[MrMPFR]

But not really much over the PS5 Pro.

I think the GPU clock will be in the 2.5 Ghz range.

Yeh

If true Sony gonna do PS4 form factor. 2.5ghz on N3P will be crazy efficient.

 

[MrMPFR]

Post #21's PS6 extrapolation math assumes RB and Rasterizer related pipeline is unchanged. Now Kepler has confirmed TBIMR for GFX13. In addition it's possible we'll see the inclusion of additional features such as TBB, TLPBB and more clever cachemem management for rendering pipeline.
The perf scaling issues from 9070 -> 9070XT I mentioned previously are prob related to something else than RB + Rasterizer being unchanged (except for higher clocks), which makes it possible to address with PS6 despite -25% SEs (3 vs 4).
This obviously changes everything and reaching the 9070XT perf target seems possible even at lowered clocks and power budget.

I expect PS6 to be comparable to AT3 / Medusa Halo

You're right and I was wrong it seems. New pipeline allows AMD to do more with less + SE issue was overblown. -33% SE (also RB + Rasterizer) vs PS6 won't matter that much. Kepler also confirmed expanded dual issue for RDNA5, that'll help boost IPC a lot.
Now that AT4 dGPU should be ~9060XT according to Kepler the 2X bigger AT3 dGPU should indeed be comparable to the PS6. Not sure about Medusa Halo though, because then it'll have to be crazy efficient.
We'll see.

 

[ToTTenTranz]

Now that AT4 dGPU should be ~9060XT according to Kepler the 2X bigger AT3 dGPU should indeed be comparable to the PS6.

I'd say the 48CU AT3 would need to be ~12% higher clocked than the PS6's 54CU for them to be comparable.

Looking at how Sony bet a lot on clockspeeds for the PS5, I don't know if that will be the case.

 

[marees]

I'd say the 48CU AT3 would need to be ~12% higher clocked than the PS6's 54CU for them to be comparable.

Looking at how Sony bet a lot on clockspeeds for the PS5, I don't know if that will be the case.

the power budgets are vastly different between 48cu AT4 vs 54 CU PS6

One place the PS6 will have the edge is in using gddr7 memory. sony has always gone for bonkers memory. so in memory bound scenarios the PS6 should come ahead otherwise it will be in ballpark of AT4

 

[ToTTenTranz]

One place the PS6 will have the edge is in using gddr7 memory. sony has always gone for bonkers memory. so in memory bound scenarios the PS6 should come ahead

Actually, if the AT3 dGPU uses 16 channels * 24bit LPDDR6 14.4Gbps then its RAM bandwidth will be 691GB/s. If the PS6 goes with 160bit GDDR7 as currently rumored, then it's 640GB/s.

Things will change drastically if the AT3 dGPU only uses LPDDR5X, though.

 

[MrMPFR]

I'd say the 48CU AT3 would need to be ~12% higher clocked than the PS6's 54CU for them to be comparable.

Looking at how Sony bet a lot on clockspeeds for the PS5, I don't know if that will be the case.

Thought PS6 was 52CUs with 2 disabled.

Nah still nothing compared to PC.
PS5 max clk 2.23ghz
RX 6700 XT FE = avg 2.49ghz
(2.23-2.49)/2.23 * 100 = >11.66% higher clocks.

Sorry for the following math but I think it's pretty interesting:
If I use 16% IPC from 15% clockspeed bump from RDNA5 thread = 3.57ghz (9060XT ~3.1ghz)
TPU 4K native raster 9060XT -> 9070XT = 1.83x perf
RDNA5 suffers from poor intra-SE CU scaling & clock scaling (9070 -> 9070XT) + non perfect SE scaling (9060XT -> 9070XT should be ~1.92X (clock adjusted) not 1.83X).

RDNA5 prob has localized everything (except GCP) and scales perfectly from 1 -> 2 SE unlike RDNA4. So 1.83/2 * 3.57ghz = 3.27ghz
That's 2 SE x 12 CU/WGP = 9070XT perf. Pretty neat.

CU for AT3 -> PS6 = +8.33%
PS6 has an advantage in +50% non-shader logic + shorter SE (easier to feed) so let's add what appears to be another 2 CUs. +12.5%. Could be more but IDK.
3.27ghz/12.5% = 2.9ghz 52CU PS6 GPU at 9070XT perf

From prev math at iso-clocks 9070XT has +23% CU lead. with 2982mhz/2900mhz (clk difference) x 23% = +26.48% IPC vs 9070XT.

As you can see perfect SE scaling + removing other bottlenecks really pays off and if f Sony drops clocks a bit more on GPU and CPU then they can make PS4 sized quiet console (lower BOM).

 

[MrMPFR]

the power budgets are vastly different between 48cu AT4 vs 54 CU PS6

One place the PS6 will have the edge is in using gddr7 memory. sony has always gone for bonkers memory. so in memory bound scenarios the PS6 should come ahead otherwise it will be in ballpark of AT4

Yeah GDDR7 gonna guzzle electrons in comparison to 384bit LPDDR6 But -370mhz will bring power down that's for sure.

AT4 prob just gonna go larger L2 to counteract that. IIRC PS6 only has 10MB L2.
Now there's also TBIMR, universal compression, overhauled scheduling, tons of cachemem changes (efficiency mostly) and also maybe local everything (except GCP), clean slate cache (Flexcache + global sharing of everything + shared data cache lines), TLPBB and prob more.
All this provides absolutely ludicrous memory BW savings. Doubt any of them will have mem BW issues.

Actually, if the AT3 dGPU uses 16 channels * 24bit LPDDR6 14.4Gbps then its RAM bandwidth will be 691GB/s. If the PS6 goes with 160bit GDDR7 as currently rumored, then it's 640GB/s.

Things will change drastically if the AT3 dGPU only uses LPDDR5X, though.

LPDDR6 has ECC overhead. 256/288 x 640GB/s = 569GB/s. I don't expect it to tap out LPDDR6 standard though but perhaps things will change ~2-2.5 years from now. Maybe ~13gbps. ~500GB/s.

32gbps over 160bit GDDR7 sounds plausible with all the architectural changes in mind.

Yeah but that would be incredibly stupid. -33% bit PHY and slower pin speed xD

 

[marees]

ML upscaling in playstation 6 will be a huge leap forward

https://twitter.com/x/status/2017709965209723160

 

[MrMPFR]

ML upscaling in playstation 6 will be a huge leap forward

https://twitter.com/x/status/2017709965209723160

Could be. Nothing is confirmed it's just speculation based on AMD patents and research papers.

But if me theory is correct, that is GFX13 goes well beyond GFX12.5 cachemem, then PS6 and ATx lineup will annihilate 50 series in effective ML perf.