EPYC ES and stock 7551 Clock Questions

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jpmomo

Active Member
Aug 12, 2018
531
192
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Hello All,
I recently started to test a few of the EPYC 7551 CPUS. They show a base frequency of 2K but run at 3K at idle. they also show a 30x multiplier and 100MHz FSB. As the system is put under stress (various benchmarks) the frequency drops to appox. 2.5K. Is this normal? I was expecting it to run at 2K at idle and boost up to 3K when needed. I also noticed that there might be some bug in hwinfo64 where the vid would go to 1.55 and throw an alert within ipmi with the vddcr going upper non-recoverable. as soon as i shut down hwinfo64 and start something like cpu-z, it would go back down. With most of the ES versions of this CPU, I see similar behavior except that the frequency drops below 1K during bench marking. These ES versions also show VID of 1.55v in hwinfor (when the app doesn't crash!) The ES versions also show Running @ 1900 MHz 1500 mV within the bios. The stock 7551 show Running @ 2000MHz 687 mV. To add more to this mystery, i am running these tests on a couple of supermicro mb. 1. is an h11dsi-nt and the other is an h11ssl-nc. both mb were purchased off of ebay and were used. This creates another variable as I am not sure if either mb is 100%. ex. I put both of the stock 7551 CPUs (taken from a known working mb) and put them in the h11dsi-nt. one of the ram slots seems to be defective. I have focused most of this initial testing on the single socket h11ssl-nc mb. I can get all of the memory slots to be recognized with the stock CPUs. On a couple of the ES CPUs, 1 of the dimm slots is not recognized. That is probably down to the ES CPU's fault. Any feedback would be appreciated.
Thanks,
jp
 

101

Member
Apr 30, 2018
35
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8
2.52 GHz is a commonly reported windows all core load clock I've seen on a 7551P. It's been a while (several months) since I've tried hwinfo, but the last few times I did it cratered the machine completely.