Processor Intel i5-7400T in a Lenovo ThinkCentre M710q Tiny
In a repair action where the motherboard of my ThinkCentre PC was replaced, Lenovo erroneously mounted an Intel i3 instead of the original Intel i5-7400T (there was absolutely no reason to replace the processor related to that repair action).
On my complaint, Lenovo later replaced it by an original type i5.
But this new processor floods the Event-Log with WHEA Logger Events, sometimes up to
60 errors per second.
Fehlertyp: Cache Hierarchy Error
Fehlerquelle: Corrected Machine Check
This sounds like a severe hardware problem, which might be detected and correctred with a built-in firmware workaround.
Can I be sure, this hardware error never slips through the error correction mechanism?
At least it might cause some performance reduction. Once in a while, processing seems to freeze for a few seconds.
Lenovo Service tells me, this problem is negligible, it is never a functional issue, it is just a beauty problem; and I have to tolerate this behaviour.
Lenovo seems not to be willing to replace that processor,which they had installed a month before, by a defect-free device.
This is not a warranty case, because Lenovo had erroneously mounted the wrong processor - they just have to return my PC with the same processor type which I had originally purchased.
In your Intel Community Forum, I found at least three entries reporting the same WHEA-Logger-Errors, where, when said Cache Hierarchy Error could be clearly located to the processor, your advice was: the processor should be replaced.
In my case I am absolutely sure, said Cache Hierarchy Error is related to the processor:
⦁ before the change to the new Intel i5, I never had such error message .
⦁ when I set BIOS to disable "Core Multi-Processing" (which obviouslay disables processor-APIC-ID: 2), no such error message shows up.
⦁ I can prove that said error event was already registered immediately after the new processor had been mounted and while my PC was still in the Lenovo repair center.
⦁ my ThinkCentre PC has presently 3 independent Windows installations:
- the original Recovery Installation, that Lenovo installed immediately after mounting the new Intel i5
- my work-installation, updated with all latest drivers.
- a fresh Windows Installation (just for testing), without any applications, with all the latest drivers Lenovo's ThinkVantage decided to upgrade.
- in addition BIOS is updated to the latest available version
In all 3 Windows variations, the event-viewer is flooded with the same Cache Hierarchy Errors
All BIOS settings are unchanged to Lenovo's original settings, definitely unchanged speed settings (not my playground)
Do you have any documentation, that backs Lenovos claim, that said hardware error is negligible and has no functional consequences. And that I have to accept the existing "defect".
Or are you convinced, that said Cache Hierarchy Errors are indeed hardware errors, that should be fixed by a processor replacement
What is your advice, how should I proceed.
Best regards, rudiratlos
Thanks AlHill for your response!
I had already sent that machine to Lenovo Service and requested to replace the faulty i5 processor with a good one - they sent it back after 4 weeks, unchanged and without any comment on their decision.
This case is probably not a general Lenovo-Problem, but a problem of the involved Repair Station and a lack of knowledge and/or understanding at this place.
For a second attempt with the Lenovo Service Center and to be able to insist on replacing the processor, I need to present them a well founded argument.
In fact I had hoped to get a technical answer from one the community's experts visibly close to Intel personnel.
Maybe an answer sounding like
⦁ yes, we still support our answers from 4 years ago, saying, if the source of the mentioned problem is definitely the processor, this processor needs to be replaced; or
⦁ the "Cache Hierarchy Error" is detected and corrected by an internal "Machine Check Algorithm"; there remains no computational problem, i.e. computing despite this event is 100 % correct. Only a slight performance degradation remains. Hence the error message can be tolerated, though it does not look very nice; or
⦁ microcode changes in later versions correct the mentioned problem. Beginning from a specific serial number; the error message still appears, but since then should better be read as "Info" in the Windows Event-Log; or
⦁ the exact reason for that message is unknown, there are several different mechanisms reporting the same message. Some but not all of these cases are harmless, but not all. Definitely replace the processor in mind;
⦁ or something similar.
Regarding my background: for more than 25 years at IBM, I was a key-engineer in hardware development, including logic boards for specialized Banking and Retail Terminals. Designing and implementing testing strategies and cooperating with the manufacturing people to match their product testing machinery, was always a major task. Circuit testing as well as its limits is therefore nothing strange for me.
It is no surprise, that the "Intel Processor Diagnostic Tool" doesn't detect anything abnormal, i.e. does not detect the "Cache Hierarchy Error".
My original question was;
- Do you have any documentation, that backs Lenovos claim, that said hardware error is negligible and has no functional consequences. And that I have to accept the existing "defect".
- Or are you convinced, that said Cache Hierarchy Errors are indeed hardware errors, that should be fixed by a processor replacement