AMD has released a new AGESA 1.2.0.2 patch to correct the high intercore latency experienced by Ryzen 9000s (tested here and here) with the previous AGESA 1.2.0.1A code. Good news for performance.
AGESA 1.2.0.2: better latency on Ryzen 9000!
Apparently, following the release of the previous firmware, version 1.2.0.1A, some users noticed that intercore latency had increased significantly. Indeed, with this version, latency was around 180 ns, which is higher than the previous-generation Ryzen. Fortunately, the new firmware has corrected the situation, and latency is now lower. New tests have been carried out, showing a latency of 75 ns. HardwareLuxx also confirms this phenomenon: 200 ns before update, 95 ns after.
Of course, these reductions bode well for processor performance, particularly in benchmarks and games. On Cinebench R23, this update results in a 1% increase in the multi-core score, from around 400 to 600 pts, although this is more of a side-effect than a desired effect.
Now it remains to be seen what happened with the previous patch. Could it be a software or hardware problem? Or simply a fault in the latency readings of the measurement software? Some suggest that rather than a patch, AGESA 1.2.0.2 simply adjusts CPU-related parameters. In any case, this seems to have been resolved.