Perhaps it can be said that Windows 11 and AMD Ryzen processors have not been better run-in so far, and the original 21H2 version was just released to the public last year, and problems related to CPPC2 were found. These issues were later fixed with a chipset driver update.
Now with the recent release of Windows 11 version 22H2, it looks like a new problem is plaguing Zen 4-based Ryzen 7000-series CPUs. CapFrameX (CFX) found that when the 16-core Ryzen 9 7950X’s single CCD (CPU compute chip) was activated, the configuration outperformed the default dual CCD 7950X. Each Zen 4 CCD has 8 cores and its cache, so, in essence, an eight-core Zen 4 CPU can outperform a higher core-count 16-core.
In order to better understand the problem and evaluate the scenarios affecting it, CFX decided to test two other conditions with simultaneous multithreading (SMT) disabled. So with a single CCD with SMT disabled, the 16-core, 32-thread 7950X is now reduced to an 8-core, 8-thread CPU. Just like the single CCD case, the case with SMT turned off produced similar results, showing better performance with fewer threads.
Perhaps it can be said that Windows 11 and AMD Ryzen processors have not been better run-in so far, and the original 21H2 version was just released to the public last year, and problems related to CPPC2 were found. These issues were later fixed with a chipset driver update.
Now with the recent release of Windows 11 version 22H2, it looks like a new problem is plaguing Zen 4-based Ryzen 7000-series CPUs. CapFrameX (CFX) found that when the 16-core Ryzen 9 7950X’s single CCD (CPU compute chip) was activated, the configuration outperformed the default dual CCD 7950X. Each Zen 4 CCD has 8 cores and its cache, so, in essence, an eight-core Zen 4 CPU can outperform a higher core-count 16-core.
In order to better understand the problem and evaluate the scenarios affecting it, CFX decided to test two other conditions with simultaneous multithreading (SMT) disabled. So with a single CCD with SMT disabled, the 16-core, 32-thread 7950X is now reduced to an 8-core, 8-thread CPU. Just like the single CCD case, the case with SMT turned off produced similar results, showing better performance with fewer threads.
Perhaps it can be said that Windows 11 and AMD Ryzen processors have not been better run-in so far, and the original 21H2 version was just released to the public last year, and problems related to CPPC2 were found. These issues were later fixed with a chipset driver update.
Now with the recent release of Windows 11 version 22H2, it looks like a new problem is plaguing Zen 4-based Ryzen 7000-series CPUs. CapFrameX (CFX) found that when the 16-core Ryzen 9 7950X’s single CCD (CPU compute chip) was activated, the configuration outperformed the default dual CCD 7950X. Each Zen 4 CCD has 8 cores and its cache, so, in essence, an eight-core Zen 4 CPU can outperform a higher core-count 16-core.
In order to better understand the problem and evaluate the scenarios affecting it, CFX decided to test two other conditions with simultaneous multithreading (SMT) disabled. So with a single CCD with SMT disabled, the 16-core, 32-thread 7950X is now reduced to an 8-core, 8-thread CPU. Just like the single CCD case, the case with SMT turned off produced similar results, showing better performance with fewer threads.
This doesn’t appear to be an isolated case, as experienced hardware benchmarker Hardware Unboxed (HBU) noticed a similar issue on their RTX 4090 test system. Obviously, this has happened more frequently in recent times.
Performance issues seem to be prevalent on Windows 11 22H2 (via @OneRaichu), and from the looks of it, it appears that Windows 11 22H2 is having scheduling issues on the new Ryzen 7000 CPUs, which is why more threads aren’t helping the OS engage in computing. There could also be a driver bug here similar to what happened recently with NVIDIA-like drivers. Perhaps the GPU driver itself is not utilizing the extra threads correctly.
