Reportedly finalized specs for RDNA 3 GPUs emerge online: AMD is allegedly pushing the boards hard as "Nvidia is going crazy with power"
As we move closer to the launch of next-gen GPUs from AMD and Nvidia, leakers keep revising the purported specifications of the upcoming graphics boards. For instance, hardware leaker kopite7kimi made some changes to his estimated specs of the Nvidia’s RTX 40 cards over the past few weeks. Now, leaker SkyJuice has posted the final configurations of AMD’s RDNA 3 GPUs.
Per SkyJuice, AMD’s design philosophy for the RDNA 3 centers around getting high performance from smaller, cheaper GPUs. For instance, AMD has allegedly reengineered the Compute Units and Optimized Graphics Pipeline, “trimming the fat in pursuit of the lowest area and cost”. The company has also halved individual Infinity Cache block sizes.
According to the specs posted by SkyJuice, AMD’s flagship Navi 31 (gfx1100) GPU will feature one GCD (308 mm2) and six MCDs (37.5 mm2), matching a previous report in which we detailed that RDNA 3 won't feature multiple GCDs. There will be 48 RDNA 3 WGP or 96 legacy CUs. The vanilla Navi 31 SKU, possibly the RX 7900 XT, will enjoy 96 MB of Infinity Cache down from 128 MB of the Navi 21 (RX 6900 XT).
AMD is also reportedly developing an SKU with a 3D stacked MCD that takes the Infinity Cache to 192 MB. Finally, Navi 31 will have a 384-bit wide bus.
SkyJuice also mentions a cut-down Navi 31, possibly the RX 7800 XT, will feature 42 WGP, five MCDs with 80 MB of Infinity Cache, and a 320-bit wide bus.
Moving on, the mid-range/high-end Navi 32 (gfx1101) will allegedly combine one GCD (200 mm2) with four MCDs (37.5 mm2), 30 WGP/60 legacy CUs, three shader engines/six shader arrays, and a 256-bit wide bus. There will be 64 MB of Infinity Cache which is lower than 96 MB of the Navi 22 (RX 6700 XT). The leaker suggests that Navi 32, set to feature in RX 7700 XT, will break cover in 2023, which is something we reported on a short while ago.
Finally, the low-end Navi 33 (gfx1102) is said to be a “mobile-first” effort from AMD. The GPU will reportedly rock a monolithic design with 16 WGP/36 legacy CUs, two shader engines, 32 MB of Infinity Cache, and a 128-bit wide bus. The surface area of the chip is a rather small 203 mm2.
According to SkyJuice, Navi 33 is more powerful than the flagship Intel Alchemist board and is “less than half the cost to make and pulling less power.”
So how accurate are these specs detailed by SkyJuice?
Tom from the Moore’s Law is Dead YouTube channel thinks they are spot on, for the most part. Per one of his sources, “Angstronomics article is the most accurate attempt at a specs summary I’ve seen so far.” The same source suspects that Navi 31 won’t be more than double the performance of Navi 21 without using >350 W.
Additionally, a source from within AMD confirmed to Tom the aforementioned design goals of RDNA 3, ”RDNA 3 has a heavy focus on perf/area and perf/watt.” The source also suggests that AMD had initially planned Navi 31 to have a 320-375 W TDP for a 50-60% improvement in perf/watt over Navi 21. But the company is now allegedly “pushing these configs harder now that we know Nvidia is going crazy with power.”