How AMD’s Ryzen 7950X3D V-Cache works on Windows

The X3D variants of AMD’s Ryzen 7000 CPUs are tearing up the performance benchmarks, especially for gaming builds. But what makes the Ryzen 7950X3D better than the standard 7950X, and the similar designs without the upgrade? It’s all about the cache, baby. Gordon Ung breaks it down for you in the latest video on the official PCWorld YouTube channel.

In layman’s terms, the X3D versions of the three Ryzen 7000 chips AMD is selling with V-cache (Ryzen 7950X3D, 7900X3D, and Ryzen 7 7800X3D) get an extra boost of 64 megabytes of L3 cache on half of its processor cores. In processor-intensive tasks like big games or media applications, these cores become dedicated to performance, relegating the cores without the extra cache to background tasks. It’s similar to Intel’s performance and efficiency cores, but handled more directly.

In actual use, things get a little more complicated. Technically the cores without the boosted V-cache run at a slightly higher clock than the other cores due to some basic hardware controls. In most cases Windows-based systems should automatically run games and other intensive applications on the V-cache cores. But in the cases where it doesn’t, you can force apps like Cinebench to use the V-cache cores with the Windows Game Bar “remember this is a game” setting.

What kind of boost can you expect when using those V-cache cores versus the standard cores? According to some basic benchmarks, the single-core results will match the non-X3D versions of the same chips when running without that cache. When the Cinemark benchmark is forced to use the V-cache cores via Game Bar, it actually runs a little more poorly — this is because those cores are clocked slightly lower. But in an actual game benchmark like the reliable Shadow of the Tomb Raider test, the game shows a shocking 20 percent improved framerate when running on the cores with V-cache.

Generally the Game Bar setting is enough to manage which apps should use the V-cache cores and which shouldn’t. But if you want more fine control, you can pop into your motherboard’s BIOS and flip the CPPC Dynamic Prefered Cores setting from Auto to Frequency (force run on non-cache cores) or Cache (forced to run on V-cache cores). This setting varies from manufacturer to manufacturer, but usually it’s found under SMU options.

Unfortunately the option to test individual games on standard cores versus V-cache cores isn’t easily visible in AMD’s Ryzen Master program. But with a little tweaking you can see which games benefit from the extra cache, and which ones don’t (if any). For more deep dives into the latest high-end PC hardware, be sure to subscribe to PCWorld on YouTube, and check our our Ryzen 9 7950X3D review for our full analysis of AMD’s ferocious new gaming flagship.

Author: Michael Crider, Staff Writer