MDS / Zombieload Mitigations Come At A Real Cost, Even If Keeping Hyper Threading On

[*ZIM*]

If SkyLake doesn't contain hardware mitigations for most Spectre/Meltdown/MDS/whatever vulnerabilities, I will stop buying Intel CPUs.

Pustulio demands your attention. I am Putulio's official spokesman, you will continue to buy Intel CPU's at inflated prices, that will pleeese Pustulio.

[ntropy]

Any good AMD notebooks around lately? I am looking at the Lenovo Ideapad that I like a lot

[tajjada]

I thought I mentioned it in the article, but yes it's coming.

Please include an AMD FX/Bulldozer CPU for comparison. I have friends who have such systems and we are genuinely interested in the results.

It would also be funny to see how the performance of Intel CPUs after all these mitigations compares to the AMD CPU generation that everyone made fun of for having bad performance.

[birdie]

According to the detailed Intel breakdown my 8th gen Skylake is vulnerable to all of the above. Some specific 8th gen processors have mitigations for specific types of MDS, but not mine. My laptop is a new model that was released 3 months ago.

I assume you meant Cascade Lake, but I doubt that design is far enough out to have hardware corrections for this kind of thing. Probably more like Ice Lake or whatever.

I was stupid yesterday. I meant Ice Lake, not SkyLake. Sorry.

[fguerraz]

Would be good to see cumulative performance hit since before Spectre/Meltdown/etc and after these new issues.

Yes, but if you do please recompile the kernel without retpolines, without this, you're still comparing apples to oranges.

[tchiwam]

Any good AMD notebooks around lately? I am looking at the Lenovo Ideapad that I like a lot

I have this HP Elitebook 755 with a 2700U in it and 32GB running at 2666 and it's a good machine with a good feel.
I'd wait for the 3xxxU series.

[chithanh]

Any good AMD notebooks around lately? I am looking at the Lenovo Ideapad that I like a lot

Avoid the Ryzen Ideapads.

Honor Magicbook 2019 looks nice, and it already comes with 3000 series Ryzen.

[DrYak]

So my question is this really Intel taking shortcuts and producing less secure architectures than AMD? Or is it just that AMD is getting less hammered by researchers and hackers looking for vulnerabilities?.

Yes, it is Intel taking short cuts that nobody in their right mind should be taking.

It's partly due to horrendously insecure short-cuts that only they took (Metldown: speculatively looking into privileged memory, before access clearance has been confirmed. Meanwhile AMD CPUs stall and patiently wait until access rights are confirmed), and also how much over-the-top their optimisations are pushed (their CPUs executes an insane amount of speculative steps in advance, enabling to manage whole tricks during this speculation that aren't available on AMD pipeline: see difference in susceptibility in speculative branches).

MDS/Zombieland relies on optimisations tricks that Intel is the only single company to have attempted.

AMD and ARM are a lot more conservative in their designs. It comes at a performance costs in some benchmarks. But also means that a lot less exploitable flaw are found, despite the latter (ARM) being ultra-popular on smartphone and in embed hardware, thus making it a juicy target to find exploits on (very few ARM cores do speculative execution to begin with, and very few take dangerous shortcuts like Intel - over all ARM tend to be a lot less susceptible to such attacks, even if black hat hacker would be rejoicing at the taught of mass-pwning smartphones and IoT devices).

[skeevy420]

Just Fucking Terrific. Apparently this effects my Westmeres.

cat  /sys/devices/system/cpu/vulnerabilities/mds
Vulnerable: Clear CPU buffers attempted, no microcode; SMT vulnerable

Guess it's time to update my my mitigation free Grub entries.

[Guest]

This relies on the assumption that Intel is actually making or selling "secure" chips at all. So far they didn't.

I'm actually pretty sure they won't and will rely on the OS and the "user choice"

My idea is that they could announce such chips in the future, and it doesn't even matter whether they'll actually be secure. The point is that they could be trying to pull off such a marketing stunt.