The X3D variants of AMD’s Ryzen 7000 CPUs are destroying performance benchmarks, especially for gaming builds. But what makes the Ryzen 7950X3D better than the standard 7950X, and similar designs without an 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 that AMD sells with V-cache (Ryzen 7950X3D, 7900X3D, and Ryzen 7 7800X3D) get an additional boost of 64 megabytes of L3 cache in half its cores. In processor-intensive tasks such as large games or media applications, these cores become dedicated to performance, shifting the cores without additional cache to background tasks. It’s similar to Intel’s performance and efficiency cores, but more direct management.
In actual use, things can be more complicated. Technically the cores without the enhanced 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 V-cache cores. But in cases where it doesn’t, you can force apps like Cinebench to use V-cache cores with the Windows Game Bar’s “remember it’s a game” setting.
What kind of improvement can you expect when using V-cache cores compared to standard cores? According to some basic benchmarks, the single-core results match the non-X3D versions of the same chips when running without that cache. When the Cinemark benchmark was forced to use V-cache cores through the Game Bar, it actually ran a little worse – this is because the cores are clocked a little lower. But in an actual game benchmark like reliability Shadow of the Tomb Raider test, the game showed a staggering 20 percent improved framerate when running on cores with V-cache.
Usually the Game Bar setting is enough to manage which apps should use V-cache cores and which should not. But if you want better control, you can pop into your motherboard’s BIOS and flip the CPPC Dynamic Preferred 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 is usually found under SMU options.
Unfortunately the option to test individual games on standard cores versus V-cache cores is not readily available 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 deeper dives into the latest high-end PC hardware, be sure to subscribe to PCWorld on YouTube, and check out our Ryzen 9 7950X3D review for our full analysis of the new gaming flagship at AMD.