AMD EPYC Genoa-X CPU Spec Sheet Breaks Cover With Monstrous Pile Of 3D V-Cache
Leaked specifications of two upcoming AMD EPYC Genoa-X CPUs reveal that these chips will feature over 1GB of L3 cache with the integration of 3D V-Cache technology. Known as 100-000000892-04 and 100-000000892-06 respectively, both CPUs are fitted with a 64MB slab of 3D V-Cache on top of all 12 (yes twelve) of its Zen 4 dies. This makes for a total of 768MB of L3 cache from the 3D V-Cache alone. Combine this with the standard L2 and L3 cache integrated on the Zen 4 dies, and you get a grand total of 1248MB, or 1.25GB, of combined L2+L3 cache.
1.25GB of cache is the largest cache capacity we have seen on any single CPU to date. This colossal amount of cache aims to improve the performance of latency-sensitive workloads in the server industry, such as simulation and computational fluid dynamics. The leaked spec sheet reports that both Genoa-X processors will feature 96 cores with a combination of 1152MB of L3 cache, 96MB of L2 cache, and 3072KB of L1 cache. Clock speeds are rated at 3.7GHz, and the chip's TDP will be configurable, ranging between 320W and 400W.
If the leaked specs are true, Genoa-X will be a massive upgrade in both core count and cache capacity from previous-generation Milan-X processors. For perspective, AMD's previous-generation flagship with 3D-Vcache – the EPYC 7773X – had "just" 64 cores and 786MB of L3 cache. So with Genoa-X, AMD has effectively added half the CCD (die) count of the 7773X to the new parts to make up the 50% increase in core count and L3 cache size. Even compared to normal EPYC 9004 series Genoa, the upgrade in L3 cache is substantial, going from 384MB on the 9654/P to over 1GB on the Genoa-X variants.
It will be very interesting to see how modern-day HPC workloads can benefit from the immense amount of L3 cache Genoa-X will offer. Previous generation Milan-X was already seeing astonishing speed improvements from the 3D V-Cache model, with some applications seeing as much as a 77% jump in performance compared to standard Milan EPYC CPUs. Based on this, we wouldn't be surprised if Genoa-X sees the same benefits, and possibly more, considering the additional core count and Zen 4 CPU architecture Genoa-X has, on top of the bigger L3 cache capacity.