Semiconductor engineer Tom Wassick has discovered what he believes to be 3D V-Cache functionality on one of AMD’s best GPUs, the RX 7900 XT. The engineer took a peak inside the 7900 XT’s die with infrared imaging and found the same type of 3D V-Cache connection points used on AMD’s Zen 3 and Zen 4 architecture. Wassick spotted the connections on the MCD die. 

Wassick cannot say if these TSV connection points will be used for caching purposes specifically, but AMD has made no known plans to expand its 3D packaging capabilities beyond vertically stacked cache at this point. That makes it seem like these connection points would be used with some sort of 3D cache in mind to increase gaming performance and/or compute performance. 

The discovery comes after numerous unconfirmed rumors that AMD would add 3D V-Cache tech to its GPUs. 

3D V-Cache has been used to great success on AMD’s Ryzen and EPYC CPUs so far. The technology relies on a hybrid bonding technique that fuses an additional 64MB slab of cache on top of a Ryzen or EPYC compute die to increase L3 cache capacity. Currently, this 3D stacking technique has allowed AMD to double the amount of L3 cache available to its desktop Ryzen 9 7900X3D and 7950X3D parts while tripling it on its Ryzen 7 5800X3D, 7800X3D consumer chips and EPYC Milan-X server processors. 

The performance benefits from this technology have been impressive, with 3D-V-Cache chips gaining a full generational increase in performance in applications that benefit heavily from large chunks of cache. A good example of this is with the Ryzen 7 5800X3D where we saw a 28% uplift in gaming performance against the Ryzen 9 5900X, and 7% faster performance than the Core i9-12900KS.

AMD’s server counterparts are even more impressive, with Milan-X benchmarks from AMD and Microsoft