AMD RDNA 3 seems ready to integrate 3D V-cache
With the release of AMD Ryzen 7000X3D series chips at CES 2023, what the new stackable cache technology can bring to the Zen 4 processor has attracted much attention. Based on a new teardown of the Radeon RX 7900 XT, we have reason to hope that the same technology will find its way to a graphics card near you.
what else can you see The linear array of “dots” looks very much like an exclusion zone on X3D, and is on the same 17-18 um pitch. Are they considering a stacked MCD feature (or maybe something else)?January 27, 2023
Tom Wassick, a self-proclaimed “semiconductor packaging engineering professional,” Teardown the new Radeon RX 7900 XT (opens in a new tab) Use infrared imaging to gain insight into its guts. The same 3D V-cache connection used in the AMD Ryzen 5800X3D exists on the MCD chip in the Radeon RX 7900 XT, although there is a blank silicon die where the compute-capable chip could sit, he said.
It is unclear whether this type of connection is used exclusively for 3D V-cache, because Tom’s Hardware (opens in a new tab) Note, but that’s the only thing AMD has announced so far for its chiplet stacking technology.
AMD has long been rumored to be introducing 3D V-cache into its GPUs after a successful implementation in its Ryzen 5800X3D processors, as well as the upcoming Ryzen 9 7950X3D, Ryzen 9 7900X3D, and Ryzen 7 7800X3D due in February.
What can the 3D V-cache even do for the GPU?
The idea behind V-cache is to place a block of cache memory on top of a processor’s computing cores using hybrid bonding. This can greatly expand the amount of cache available, saving the processor critical clock cycles as it does not have to make further accesses to conventional memory to fetch data or instructions.
As far as the computer’s CPU is concerned, this would greatly improve gaming performance, but it’s not clear that the GPU cache will achieve this kind of performance boost, although it may improve.
Another issue is thermal performance, which is an especially important consideration for graphics cards. When using 3D V-cache, cooling is complicated by an additional cache board on top of the processor’s compute cores. AMD may have to slow clock speeds to compensate, which may negate any gain the extra cache can provide.
It’s unlikely we’ll see these developments on mainstream Radeon cards this year, but we should expect them to drop during a mid-cycle refresh for cards like the RX 7950 XT or RX 7650 XT, probably sometime in late 2023 or early 2024.