"The traditional performance IPC of RDNA4 is expected to increase by about 12% compared to RDNA3, while the improvement in light pursuit will be huge (hardware BVH traversal), and the IPC is expected to increase by about 25%.
RDNA4 should be a single-chip design, using TSMC N4P process, with a smaller area, so the cost is very low. The video memory should be GDDR6. The graphics card will be very cost-effective."
My personal copium about RDNA 4 then (bad maths incoming):
Assuming a baseline 20% extra clocks for RDNA 3 (so, 3Ghz across the board), and 15% general better performance.
Assuming that the general RT performance promised here is correct, so 25% better across the board.
Assuming also that RDNA 4 will have an extra 10% clocks, so it won't be 3Ghz base but rather above 3.2Ghz. It's on N4P, so that's not an unrealistic expectation. And also the promised 12% extra raster.
And assuming that the lack of BVH walker indeed is the reason that RDNA suffers so damn much in NV-RT games like Cyberpunk.
With a die that, in raster, will provide somewhat above 7900 xt performance:
Raster:
So let's cut the apple in half and say that, counting the extra it's right in the middle between an XT and XTX.
150 FPS base at 1440p for N48.
Remove 12% extra perf iso clocks, and 15% perf for extra clocks.
150 x .12 == 18
132
132 x .15 == 19.2
112.8 FPS
We're in the ballpark of a 7800 xt at 109.3 FPS base. Since N48 is a 256 bit bus thing, I don't expect it to shine hard at 4K, my 7900 xt and its 320 bit bus already takes more Ls than it should vs an XTX's 384 bit.
Now taking a 7800 xt as base:
Taking 41 FPS at 1440p base, adding 15 + 12 general perf:
41 * 1.12 = 45.92 (46)
42 * 1.15 = 52.9 (53)
I don't think the RT rep is "25% more on top of 12%" so that's 13%:
53 * 1.13 = 59.89 fps, so we're nearing 60 FPS average, with RT on, at 1440p.
If my copium proves true, then it won't be just 20% more clocks but more like 30%, from ~2.5GHz to ~3.3Ghz. So we can add a broad 10% improvement to all of that, up to around 66 FPS average with RT on at 1440p. Don't have a clue how well it'll fare on 4K with that bus, but
just upscale it.
Now the real question is how many of these games are crippled from the lack of a BVH walker. It used to be that an XTX did an abysmal 9 FPS at 4K with Path Tracing on in CP2077. Now I see a 7800 xt doing 26.9 in the tomshardware article at 1440p, so maybe something was fixed/accelerated somewhere since, or maybe "RT Ultra" doesn't mean Path Tracing on.
My understanding was "AMD raytracing is poor, but not even close to unusable for 90% of RT, and when you have too many light bounces, it falls off a cliff and becomes unusable". BVH HW walker was meant to get the unusable into playable and to up the general perf.
I can assume that a general 25% improvement + 30% more clocks so around 25% better perf is there. That's good, but it's just reaching a 4070 Ti and its 68 FPS average here. Reaching a 4070 Ti tier of RT with a 240mm² die is damn impressive, but nobody's gonna clap for AMD yet again reaching last generation's performance.
So my only hope at this point, that we'd go above a 4070 Ti and at least to a Super's general perf, is that the BVH walker goes beyond "just 25%" and sometimes takes unusable RT with too many light bounces into usable RT. As in, you have 25% general RT improvement, but in some games, it's 100% or more. Possibly up to 150% more.
If AMD has effectively fixed the last thing that made their RT worse outside of software (which still takes years of work), then they have a strong contender that'll reach circa 4070 Ti Super and possibly get closer to a 4080's RT performance, while raster is already 4080 level anyway. For a card they'll sell for $600 and that could be financially viable for $400, that's a really great product, and a great heir to the 7800 xt which I think is by far the best offering AMD has had this gen.
The Copium is on. Make me dream of functional 1440p path tracing, AMD. 4K I know won't happen without maximum upscaling, but let me dream. And the raster perf, well, it'll make a near XTX level of perf, so I'm not worried that it'll handle everything raster well enough, especially for that price.