Remember the infamous RTC bug that caused AMD Ryzen 3000 (codenamed Matisse) chips to actually run faster than expected? Now, the bug doesn’t seem to go away and can affect AMD’s latest Ryzen 7000 (Raphael) processors, which rival the best CPUs on the market.
Russian tech blogger professional tech (opens in new tab) One of our subscribers has shared a video showing the Ryzen 9 7950X coming out of sleep mode and reaching clock speeds of 6.28 GHz. This is clearly a bug as the Ryzen 9 7950X has a clock speed of 5.7 GHz, making it impossible for a 16 core chip alone to exceed 6 GHz without manual overclocking. Unfortunately, users do not share motherboard models or firmware versions. So it’s unclear if a specific AMD AGESA firmware is the cause of the bug.
The trick reportedly consists of letting the Ryzen processor reach its maximum clock speed and then putting the system to sleep. As a result, clock speeds magically skyrocket exponentially. The processor appears to run faster on benchmarks like Cinebench and Corona. Instead, what looks like a recurrence of the RTC bug is fooling the benchmarks.
The RTC bug dates back to 2013 in the Windows 8 era. At the time, this flaw was more pronounced in Intel processors such as Sandy Bridge, Ivy Bridge and Haswell. AMD processors were affected, but not as much as Intel processors. RTC bugs were primarily related to processor bus frequency changes. Changes made within the BIOS were acceptable, but changing the frequency at the software level messed up the Windows 8 timers.
Benchmarks such as Cinebench and Corona measure how long it takes your processor to render a scene. If the internal timer is slow, the software perceives the processor to take less time to complete the benchmark. When the user measures the time with a stopwatch and compares the time displayed by the software, the big difference becomes apparent. The user who submitted the video confirmed that he had a 15% difference in rendering time between the two measurements. So the combination of anomalously high clock speeds and RTC bugs gives the illusion that Ryzen processors are delivering more performance, but they aren’t.
Microsoft is reported to have fixed the RTC bug in newer versions of Windows, but Zen 2 chips were still susceptible to the problem. We’re on Zen 4 now, and the bug apparently hasn’t gone away. This bug does not break your system or degrade performance. Inexperienced users, on the contrary, believe that the processor is overworked. Ultimately, this is a placebo effect that users and reviewers should be aware of. Especially for the latter, as bugs tip the scales towards his Ryzen processors.
