AMD RDNA 3 appears to integrate 3D V-cache

With the announcement of the AMD Ryzen 7000X3D-series chips at CES 2023, a lot of attention has been paid to what new stackable cache technology can bring to Zen 4 processors. According to a new analysis of Radeon RX 7900 XT, there’s reason to hope that this same technology makes its way to a graphics card near you.
What else can you see? A linear array of “points” looks a lot like the isolated regions on X3D and has the same pitch of 17-18 um. Maybe they’re looking at a stacked MCD function (or maybe another)?January 27, 2023
Tom Wassick, self-proclaimed “semiconductor encapsulation engineering expert”, tearing apart the new Radeon RX 7900 XT (opens in a new tab) to delve into its intestines using infrared imaging. He says that the same type of 3D V-cache connection used for the AMD Ryzen 5800X3D exists on the Radeon RX 7900 XT’s MCD die, although there’s an empty piece of silicon where the compute die can enter.
It is not clear if this connection type is specific to 3D V-cache, because Tom’s Hardware (opens in a new tab) pointed out, but that’s the only thing AMD has announced so far for its chiplet stacking technology.
It has long been rumored that AMD will include 3D V-cache in its GPUs after successfully implementing it in its Ryzen 5800X3D processors, as well as the upcoming Ryzen 9 7950X3D, Ryzen 9 7900X3D, and Ryzen 7 7800X3D coming out next month. Two.
What will 3D V-cache even do for the GPU?
The idea behind V-cache is to use hybrid linking to place a slab of cache on top of the processor’s compute cores. This can greatly expand the amount of available cache memory, saving the processor critical clock cycles as it doesn’t have to go further out of memory to fetch data or instructions. .
In terms of the computer’s CPU, this produces a significant boost in gaming performance, but it’s unclear if such a performance boost will be achieved with GPU cache, although it’s likely to see a slight increase in performance. number of improvements.
Another issue, however, would be thermal efficiency, a particularly important consideration for a graphics card. With 3D V-cache, the extra buffer on the processor’s compute cores complicates the cooling process. AMD may have to reduce the clock speed to compensate, which could negate any benefit the extra cache might have provided.
We’re not likely to see these developments on the mainstream Radeon cards this year, but we can expect them to drop in mid-cycle refreshes on cards like the RX 7950 XT or RX 7650 XT, maybe around late 2023 or early 2024.