AMD Simulated RX 7800 XT Performs Equally to RX 6800 XT

Igor’s Lab has taken on the duty of simulating an RX 7800 XT to see what efficiency would possibly appear to be. This was performed utilizing AMD’s new Radeon Pro W7800 graphics card, with half the reminiscence in any other case occupied. Igor’s simulation outcomes and theoretical calculations put this theoretical 7800 XT roughly between an RX 6800 XT and RX 6900 XT, or between Nvidia’s competing RTX 4070 and 4070 Ti.

The Radeon Professional W7800 is a part of AMD’s W7000 sequence workstation GPUs, that includes its newest RDNA 3 GPU structure. The GPU sports activities 70 compute models utilizing AMD’s Navi 31 die, with 32GB of reminiscence and a complete board energy score of 260W. As a result of this, the W7800 is arguably the very best present candidate for simulating a theoretical RX 7800 XT. That is as a result of it has a 256-bit reminiscence interface, the identical because the rumored RX 7800 XT; disabling half of the VRAM ought to be a fairly shut stand-in for the longer term GPU.

Igor offered two completely different take a look at eventualities. The primary concerned bodily simulating a 7800 XT by artificially disabling half of the reminiscence, leaving the GPU with 16GB of GDDR6 VRAM. The second used theoretical calculations taken from the facility effectivity outcomes of the RX 7900 XT. The latter was performed to try to offer a “extra correct” image of how an precise RX 7800 XT could carry out, for the reason that W7800 is tuned for effectivity slightly than efficiency.

It hopefully goes with out saying, however each eventualities are at finest an estimate of efficiency. There are a number of points, together with closing clock speeds, core counts, whether or not the “disabled” VRAM really mimics a 16GB card, drivers, and extra. Igor examined at 1080p, 1440p, and 4K. The “simulated” and “calculated” W7800 outcomes have been comparatively shut, with the simulated outcomes trying much like an RX 6800 XT whereas the calculated outcomes look extra like an RX 6900 XT. Our GPU benchmarks hierarchy by the way places the 6900 XT about 7% forward of the 6800 XT. This is the general 1440p chart:

Igor's Theoretical RX 7800 XT Benchmark, 1440p

(Image credit: Igor’s Lab)

Igor used 9 video games for his testing, two of which have ray tracing enabled (Cyberpunk 2077 and Metro Exodus Enhanced Version). If the RX 7800 XT performs equally to what he measured, you’ll be able to see why AMD will not be dashing to carry the RX 7800 XT to market. It might be extra environment friendly than the RDNA 2 GPUs, however efficiency would not be a lot better. That will give little or no purpose for anybody to improve to the brand new RDNA 3 GPU, relying on pricing, for the reason that RX 6800 XT currently starts at $519.

We do should reiterate that Igor’s predictions seemingly aren’t totally correct. The RX 7800 XT’s specs stay confidential at this level, so we do not know what it’s going to have by way of compute models, shaders, cache, and GPU clocks. The W7800 additionally makes use of a trimmed down Navi 31 GCD with 70 CUs, whereas rumors point out the RX 7800 XT will use a Navi 22 GCD with 60 (probably 64) CUs. Relying on closing clocks, the buyer card could or could not ship higher efficiency than Igor’s simulated outcomes.

One other drawback is drivers, as workstation drivers are usually much less optimized for gaming and extra optimized for skilled functions. It is doable that drivers tuned for gaming might enhance efficiency fairly a bit.

Lastly and maybe most significantly, we additionally do not know what the value of the presumed RX 7800 XT might be. Given the rumored specs, $600 might be probably the most AMD might ask, and it might doubtlessly promote for much less. Even when it solely matches the efficiency of the prevailing RX 6800 XT, if it has an analogous value and makes use of much less energy whereas offering a number of new extras (like AV1 encoding assist), it might nonetheless be an honest card.

There’s little purpose to anticipate an enormous generational uplift in efficiency, sadly. The RX 7600 barely beats the earlier era RX 6650 XT, with each playing cards utilizing 32 CUs with 8GB of 18 Gbps GDDR6 reminiscence. The RX 7900 XT does beat the RX 6950 XT by round 17% in our testing, but it surely additionally options 84 CUs with 20GB of reminiscence in comparison with 80 CUs and 16GB of reminiscence. Trim the CU depend all the way down to 60–64, and efficiency would logically drop by about 25%.

We hope to see RX 7800 XT and RX 7700 XT {hardware} ship within the subsequent month or two. Efficiency will not be considerably greater than the prevailing components, however effectivity ought to be higher and the extra architectural adjustments make them (barely) extra aggressive with Nvidia’s RTX 40-series. We’ll make sure you take a look at the brand new GPUs each time they really ship.