PC Processors

[egera24]

Hi,

my specs:

CPU: AMD Ryzen 5 7600X 4,7 GHz 32 MB L3
Cooler: THERMALRIGHT Peerless Assassin 120 SE
Mobo: Gigabyte B650 AORUS ELITE AX V2 (AM5)
RAM: G.Skill Flare X5 F5-6000J3038F16GX2-FX5 32GB (2 x 16) GB DDR5 6000 Mhz
PSU: Cooler Master MWE Gold 750 - V2 750 W 24-pin ATX
Case: Montech AIR 903 MAX

I am at the end of my ideas what could be the problem and how to solve it.

I wanted to underclock my CPU with PBO Curve via negative CO offsets and I wanted to do it per core.

I am in trouble to set up my Core 0 (which is marked in HWINFO64 as best performer).

I am using the OCCT software (13.1.12 version) and I am running avx2 core cycler test for a single core (for 2 threads).

Symptomps:

1) If I use stock settings (default clock speed, no PBO, no undervolt, no overclock), it is stable, I see no errors at all.
2) If I enable the Core Performance Boost in BIOS, the OCCT stresstest throwing errors after the clock speed of the core is above about 5GHz, so after about some seconds. But only for Core 0. The other cores seems to be fine. And it does not matter if EXPO profile for RAM is enabled or disabled, the errors are presented.
3) I ran SSE test in OCCT as well for 1 hour with CPB enabled, there was no error, no crash at all.
4) If I try to enable PBO Advanced settings and I set any negative CO offset for the Core 0, the System crashes and the PC reboots (but no BSOD, no WHEA logs in Windows event viewer).
5) If I set a positive offset for this core (even +1), the stress test can run up to 20 minutes error free. After that I can see the errors again, but there is no System crash.
6) The temps are good. Even if the System crashes, the temp is below 90C. I did not set any thermal limit for these tests. I tried prime95 stress test with small FFTs and there was no crash, no errors, after 30 minutes my max temp was 95C, but it tended to be around 90, so I assume it was also OK. But as far as I know prime95 stress test is not a single core test.
7) My last try was that I have enabled the Core Performance Boost and PBO Advanced settings and I have have set a negative CPU Boost Frequency. At -25Mhz and -50Mhz I see the errors. At -100Mhz I do not see any errors during the stress test. The effective core clock is between 4.9Ghz and 5.1Ghz as I see in hwinfo64. The temp is 66C max.

I could live with a lowered boost clock of course, but I do not want to. Do you have any idea what could be the problem, why the core 0 do not capable to higher clock speeds? Or is it just silicon lottery thing?

I am attaching for the safety sake two pictures: RAM profile and CPU voltage. Maybe there is some voltage settings which are causing the issue?

https://imgur.com/a/atKP2vJ

Thank you very much in advance.

[elstaci]

I would open a AMD SUPPORT Ticket and see what they say from here: https://www.amd.com/en/forms/contact-us/support.html

It is possible that Core 0 may be locked from being over or under clocked thus causing those errors. just taking a guess though.

Since Core 0 works fine without any manual external manipulations indicates the CPU is probably not defective but due to some Core 0 engineered limits possibly.

[egera24]

Hi,

thank you very much, I have opened a support ticket (00584213). I will let you all know if there is any relevant answer or solution.

[egera24 · Accepted solution]

This was the answer from AMD, so I assume there will be no other option than accept that it is silicon lottery:

Dear Krisztián

Your service request: 00584213 has been reviewed and updated.

Response and Service Request History:

Thank you for your email.

Based on your inquiry, I understand that you are experiencing stability issues with Core 0 on your Ryzen 5 7600X.
When you attempting higher boost clocks or applying negative PBO offsets, the system experiences errors or crashes during stress tests on your system.

We would like to inform you that we do not provide support for overclocking or undervolting AMD processors, as these practices can lead to system instability. For optimal performance and stability, we recommend using the default BIOS settings.

Please note that AMD’s product warranty does not cover any damages caused by overclocking or undervolting, even if these actions are enabled using AMD hardware or software (GD-26). Additionally, since OCCT is a third-party tool, we are unable to provide guidance on its use. For stress testing, we recommend using Ryzen Master.

For the best experience, we advise keeping your system set to stock settings and ensuring that your BIOS and chipset drivers are up to date.

Thank you for your understanding.
Thank you for contacting AMD.