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Comment by wilhil | Hacker News Reader

Here here...

This is a hidden thing that seems to always go under the radar.

My Intel i7 4790k has lost at least 40% speed since I originally bought it, and for years, I always thought that Intel machines were getting slower without any actual proof whereas AMD machine I returned to after years just felt as fast as ever.

Now with microcode updates and similar getting more coverage, I'm certain that this is what it is.

AMD's partner program is meh, where as Intel is really partner focused - if anything breaks, I can get a replacement shipped to me in advanced the next day for ~3-5 years (component depending), but I am seeing much more demand for AMD as of late.

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Yeah they silently killed my overclock 9 months ago by limiting the 6850k to 38x multi due to "Spectre Mitigation". It's the worst BS ever...

If I remove the Intel microservice dll from my windows system folder then I get my 41x back, but there's been no documentation forthcoming. Just finding out why speeds were nerfed required lots of research.

Having said that I can see that Asus may have finally released the required motherboard update for this. Updating requires me to reset everything by hand, as Asus doesn't let me simply back up settings - they are invalidated between bios versions. Between that and eating CPUs if using XMP, it's the worst motherboard I ever bought.

https://www.asus.com/us/Motherboards/ROG-STRIX-X99-GAMING/He...

Needless to say my days of building Intel systems are over.

I had a system boot loop on a Intel core-i system because a microcode update "disallowed" overclocking (this happened well before the spectre/meltdown debacle).

The only solution was to prevent the os from loading the bad microcode at boot - I'm guessing that's what removing those .dlls does.

Eating CPUs?

The automatic XMP settings upped one of the more obscure voltage lines (new to me since my last CPU the 2600k, which still runs perfectly on 4.4ghz as son's PC) to dangerously high levels. I received two CPU replacements under warranty, before I found the particular setting that needed to be put under manual control. I think I was 1/3rd of my way to the third CPU dying.

This was incredibly sloppy work by Asus.

So yeah, eating CPUs.

I see I got a few upvotes, so this must resonate here - thanks, wanted to back this up with specific details:

The chipset was the Broadwell EP. VCCSA ran at ~1.33, when the maximum should have been 1.25. Also VCCIO was 1.25, when it'd run happily at 1.096v.

Point taken was to go through every single voltage setting and research safe ranges, not trust auto for _anything_. There were changes in the CPU memory controllers around this time, and that's what caused the CPU to die when unsafe voltages were applied; Asus' XMP settings for my 4x8=32GB 3200 Trident Z DDR4s (17-18-18-36) turned them to mush.

I don't have a degree in electrical engineering; it seems like Asus wanted you to have one.

Looking back I'm discovering more details... and another guy who experienced essentially the same, with others backing up the instability of the platform: https://forums.anandtech.com/threads/my-6850x-just-died-just...

Whilst I want to move over to AMD, I'd like my current 6850k to last longer as my son's computer. It seems like I won the silicon lottery with my old 2600k that he's currently using though; running fixed 4.4ghz which is a very nice upgrade from the stock 3.4ghz.

The original article in this thread is music to my ears - for AM4, just add a great cooler and away we go. It's tempting to upgrade both computers at the same time.. which kind of wrecks my hand me down thing, but I'm sure the 6850k got degraded by 3 weeks on the bad settings as I've had lots of issues with it (unlike the 2600k).

(Final edit: Thus my disdain for Asus' inability to back up BIOS settings on this board when performing BIOS updates like I should now to get my overclock back, unlike others I've had; if I miss even a single one of the voltage settings, I can expect it to fry the CPU - unless they actually fixed their sh*t in one of the BIOS updates).

My Strix X99 just kicked the bucket a week ago...is this possibly why? Shit, I've had it on XMP since I built it 3 years ago.

I've already gone through one CPU, about 4 months after I built it. Now the whole machine is just dead with no signs of life. I bought a new board assuming the board was bad but maybe I need to test the CPU now...

Agreed though, one of the worst boards I've ever bought and seriously rethinking all Asus purchases in the future.

Yeah, builds on my i7 Linux laptop are noticeably faster with Spectre mitigations disabled.

Pretty sad that mitigations against a largely theoretical attack hurt performance for everyone. Meanwhile people continue to open e-mail attachments with .scr extensions.

It's only theoretical because the majority of people are patched. Given that the possible vulnerability has been discussed since core was first released, I'd bet that certain 3-letter organizations have used this and similar exploits in the past against high-value systems.

My (perhaps naive) understanding is that, for Spectre to be truly exploitable, an attacker must be able to execute code locally (I know of the JS POC but there are browser mitigations). But if an attacker has an account in my system I'm already screwed anyway, as there are probably other privilege escalation vectors that are easier to exploit.

My laptop is not high-value so I'd rather just disable that stuff. I once timed a C++ build, with and without Spectre mitigations, and the difference was something like 20%.

Privilege escalation is the biggest issue I think. Users on modern systems don't actually run as admins by default which makes it much harder for malicious software to compromise the entire system.

Consider the average user. You can remove almost all malware and viruses because they only install and run with user permissions. Without spectre mitigations, it wouldn't be very long before all that malware was installing itself at deeper levels where the only solution is blowing everything away completely.

I'm sure there is also a DRM argument somewhere for people who like that kind of thing.

Javascript runs locally. Eg. a quick search turns up: https://github.com/cgvwzq/spectre

Relevant: make-linux-fast-again.com

Nice, thanks!

'Hear hear'

:P Thanks!

Huh, I was under the impression that mitigation of speculative execution vulnerabilities was a one-time fix that has been implemented, accounted for and forgotten years ago. I'm surprised to hear it's still a factor in anything.

New ones have been discovered regularly (more or less one every 2-4 months). Some affect AMD as well, but all affect Intel.

If only... There's been several BIOS updates for my laptops. Meltdown, Spectre, and the most recent one, again something to do with side attacks. Plus Microsoft's updates

>if anything breaks, I can get a replacement shipped to me in advanced the next day for ~3-5 years (component depending)

40% speed reduction does not really count as "anything breaks", does it? Some previously working workloads stopped working.

40%?? In what workload?

I share your incredulity. 40% sounds like total BS unless you designed benchmarks to maximally highlight potential speed loss from Spectre & Meltdown mitigations.

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