3 ms·

I've been disabling HT for security reasons on all my machines ever since the first vulnerabilities appeared, with no discernible negative impact on daily usage

I've been disabling HT for security reasons on all my machines ever since the first vulnerabilities appeared, with no discernible negative impact on daily usage.

groos 2y ago
The gain from HT for doing large builds has been 20% at most. Daily usage is indistinguishable, as you say.
- MisterTea 2y ago
  HT really only benefits you if you spend a lot of time waiting on IO. E.g. file serving where you're waiting on slow spinning disks.
  - coolspot 2y ago
    IO wait happens on OS kernel level, not on CPU level. RAM fetch latency is what happens on CPU level.
binkHN 2y ago
For security reasons, OpenBSD disables hyperthreading by default.
duffyjp 2y ago
I'm running a quite old CPU currently, a 6-core Haswell-E i7-5930K. Disabling HT gave me a huge boost in gaming workloads. I'm basically never doing anything that pegs the entire CPU so getting that extra 10-15% IPC for single threaded tasks is huge. And like you said, the vulnerability consideration makes HT a hard sell for workloads that would benefit (hypervisors). That i7 is a huge downgrade from what I was running before (long story) so I'm looking forward to Arrow Lake and I like everything I've read. In addition to removing HT, they're supporting Native JEDEC DDR5-6400 Memory so XMP won't be necessary. I've never liked XMP/Expo...