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I'm not sure why I'm being downvoted. This is a legitimate question. Does this bug make the cpu unusable? Does the work around for it slow down the per core per

I'm not sure why I'm being downvoted. This is a legitimate question. Does this bug make the cpu unusable? Does the work around for it slow down the per core performance to the point of unusability?

fivesixzero 7y ago
Whether the issue is with the CPU hardware, the mainboard design (VRM, etc), mainboard BIOS, kernel, or the Prime95 app itself still appears to be an open question. Based on oscilloscope analysis of the VRM output in a linked thread elsewhere in the comments it looks like the board’s VRM design, or its configuration by the board’s BIOS, may be the most likely suspect. But there are less-researched reports of similar issues on other boards as well, which makes things a bit more murky. Given the uncertainties there it may put some people off from buying into the TR/sTRX40 platform in general. But to offer a blanket recommendation to avoid is a bit premature.
topspin 7y ago
It's a little early to start condemning things. It might be motherboard power delivery, a prime95 bug or something else. If it is the CPU there could be a firmware correctable flaw. This is the bleeding edge; these devices have only been available for 13 weeks and someone is indeed bleeding, it seems. It could even be an uncorrectable flaw in the device design, in which case AMD will likely do as they did in 2017: replace the parts.
- boris 7y ago
  > This is the bleeding edge; these devices have only been available for 13 weeks [...] Shouldn't these devices have been tested by AMD and motherboard manufacturers for months before they were released? Including on workloads like Prime95 which are well known to uncover system instabilities. Keep in mind also that this is not the first time in the Zen/Zen2 history that AMD has shipped buggy products: there was the segfault bug, the random number generator instruction bug, and the unbootable Threadripper on recent (at the time of release) Linux kernel. The worst part, to me personally, is that they were all "surface bugs" that could have been detected by AMD with a little bit of testing. I've been wondering why Supermicro isn't releasing any Threadripper motherboards (while they do for Xeon-W). Maybe this explains it: the consumer CPU business at AMD is a circus and Supermicro wants none of it?
paulmd 7y ago
Unless it shows up in other workloads, or your workload is specifically Prime95, it doesn't make it unusable, it just means you can't do Prime95.

I'm not sure why I'm being downvoted. This is a legitimate question. Does this bug make the cpu unusable? Does the work around for it slow down the per core performance to the point of unusability?

fivesixzero 7y ago

Whether the issue is with the CPU hardware, the mainboard design (VRM, etc), mainboard BIOS, kernel, or the Prime95 app itself still appears to be an open question. Based on oscilloscope analysis of the VRM output in a linked thread elsewhere in the comments it looks like the board’s VRM design, or its configuration by the board’s BIOS, may be the most likely suspect. But there are less-researched reports of similar issues on other boards as well, which makes things a bit more murky. Given the uncertainties there it may put some people off from buying into the TR/sTRX40 platform in general. But to offer a blanket recommendation to avoid is a bit premature.

topspin 7y ago

It's a little early to start condemning things. It might be motherboard power delivery, a prime95 bug or something else. If it is the CPU there could be a firmware correctable flaw. This is the bleeding edge; these devices have only been available for 13 weeks and someone is indeed bleeding, it seems. It could even be an uncorrectable flaw in the device design, in which case AMD will likely do as they did in 2017: replace the parts.

boris 7y ago
> This is the bleeding edge; these devices have only been available for 13 weeks [...] Shouldn't these devices have been tested by AMD and motherboard manufacturers for months before they were released? Including on workloads like Prime95 which are well known to uncover system instabilities. Keep in mind also that this is not the first time in the Zen/Zen2 history that AMD has shipped buggy products: there was the segfault bug, the random number generator instruction bug, and the unbootable Threadripper on recent (at the time of release) Linux kernel. The worst part, to me personally, is that they were all "surface bugs" that could have been detected by AMD with a little bit of testing. I've been wondering why Supermicro isn't releasing any Threadripper motherboards (while they do for Xeon-W). Maybe this explains it: the consumer CPU business at AMD is a circus and Supermicro wants none of it?

paulmd 7y ago

Unless it shows up in other workloads, or your workload is specifically Prime95, it doesn't make it unusable, it just means you can't do Prime95.