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by andikleen2 2185 days ago
You have to be a bit careful with the CLFLUSH method. I tried to use it in a widely used program years ago because Intel recommended it, but we found that it just hangs the CPU on some older VIA/Centaur CPUs. Presumably that's fixed these days, but the old CPUs are likely still around.
2 comments

Thanks for the info! Unfortunately I don't have access to any VIA/Centaur CPUs, so couldn't test on those (though test results welcome if anyone is willing/able to!).

But yeah, you have to check the CPU you're running on when doing these tricks unfortunately, as results vary greatly across micro-architectures.

Interestingly, there's a more optimal CLFLUSHOPT instruction on more recent processors, which often seems to be quite effective for this task.

Funny. My line of thought was “it’s probably still not fixed, but those old cpus won’t be running new code anytime soon.”