88
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 26 Jul 2023
88 points (98.9% liked)
Privacy
31161 readers
455 users here now
A place to discuss privacy and freedom in the digital world.
Privacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy.
In this community everyone is welcome to post links and discuss topics related to privacy.
Some Rules
- Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post
- Don't promote proprietary software
- Try to keep things on topic
- If you have a question, please try searching for previous discussions, maybe it has already been answered
- Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience
- Be nice :)
Related communities
Chat rooms
-
[Matrix/Element]Dead
much thanks to @gary_host_laptop for the logo design :)
founded 4 years ago
MODERATORS
Honestly no. Remember Spectre & Meltdown vulnerabilities back in 2018? Yeah that security bug that only affected Intel CPUs until it was patched seriously told consumers and enterprise customers to “please turn off hyperthreading” to prevent exposure. Fucking LOL. Voluntarily cut my CPU performance in half!? Based on a theoretical exploit that was only found in a very specific and controlled environment before everyone started FREAKING out?
Neither spectre nor meltdown are specific to Intel. They may have been discovered on Intel hardware but the same attacks work against any system with branch prediction or load speculation. The security flaw is inherent to those techniques. We can mitigate them with better address space separation and address layout randomization. That is, we can prevent one process from reading another process's data (which was possible with the original attacks), but we can't guarantee a way to prevent malicious browser tab from reading data from a different tab (for example), even if they are both sandboxed. We also have some pretty cool ways to detect it using on-chip neural networks, which is a very fancy mitigation. Once it's detected, a countermeasure can start screwing with the side channel to prevent leakage at a temporary performance cost.
Also, disabling hyper threading won't cut your performance in half. If the programs that are running can keep the processor backend saturated, it wouldn't make any noticeable difference. Most programs can only maintain about 70-80% saturation, and hyper threading fills in the gaps. However the result is that intensive, inherently parallelizable programs are actually penalized by hyper threading, which is why you occasionally see advice to disable it from people who are trying to squeeze performance out of gaming systems. For someone maintaining a server with critically sensitive data, that was probably good advice. For your home PC, which is low risk... you're probably not worried about exposure in the first place. If you have a Linux computer you can probably even disable the default mitigations if you wanted.
Well TIL!!
I’ve been out of the builder world for long enough that I didn’t follow the 2018 bug. I’m more from the F00F generation in any case. I also took a VLSI course somewhere in the mid-90s that convinced me to do anything other than design chips. I seem to remember something else from that era where a firmware based security bug related to something I want to say was browser-based, but it wasn’t the CPU iirc.
In any case, I get the point you and others are making about evaluating the risks of a security flaw before taking steps that might hurt performance or worrying about it too much.