AMD microcode update improves CCD latency on Ryzen 9000 CPUs

Help is on the way

by · TechSpot

Serving tech enthusiasts for over 25 years.
TechSpot means tech analysis and advice you can trust.

In a nutshell: AMD's Ryzen 9000 series CPUs represented a significant improvement in many areas. However, some eagle-eyed reviewers and users noticed a potential drawback: core-to-core latency was noticeably higher in the Zen 5 architecture compared to the Ryzen 7000 chips across different core complex dies. Now, engineers have a solution to address the issue.

While the company has not officially commented on the issue, AMD has addressed it with a microcode update included in AGESA version 1.2.0.2. Some OEMs, including Asus, have already started implementing the firmware update. AGESA, which stands for AMD Generic Encapsulated Software Architecture, provides low-level tweaks to the chip's behavior.

Early testing indicates that the update significantly reduces inter-CCD latencies. One enthusiast on Overclock.net reported a dramatic decrease in cross-CCD latencies from approximately 180ns to just 75ns after applying the patch.

(Click to enlarge)

The high latencies in the Ryzen 9000 series were attributed to new tuning parameters implemented by AMD to enhance performance for specific workloads, according to the creators of the popular Y-Cruncher benchmark utility.

// Related Stories

While the latency issue may not have had a significant impact on real-world performance, many Ryzen 9000 owners are seeing improved CPU benchmark scores, such as in Cinebench R23, after applying the update. However, the increase of around 500 points is relatively minor given the chip's already impressive speed. Still, in the eyes of enthusiasts, every little bit counts.

Currently, only Asus has released BIOS versions with AGESA 1.2.0.2, and these are still in beta. If you prefer to avoid potential issues, it might be best to wait for more stable builds. Nonetheless, motherboard makers typically adopt major revisions quickly, so other vendors are likely to follow soon.

AMD's swift action to resolve the latency issue is commendable, but it wasn't the only challenge the company faced post-Zen 5 release. Enthusiasts had previously noted that the Ryzen 9000 series fell short of anticipated performance gains. AMD later identified missing "branch-prediction optimizations" as the cause and, in collaboration with Microsoft, issued a subsequent fix.