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The bug where speculatively-executed code can access privileged memory is Meltdown, and it doesn't affect AMD systems since apparently they did the sensible thi
by makomk 9y ago
The bug where speculatively-executed code can access privileged memory is Meltdown, and it doesn't affect AMD systems since apparently they did the sensible thing and blocked even speculative access to unauthorised memory addresses. Unfortunately, Meltdown apparently can't be fixed in microcode on affected Intel CPUs, so they're stuck with a performance-killing workaround that AMD CPUs don't need.
- JoeAltmaier 9y agoAgreed, except 'sensible thing' was a very slow thing for Intel architecture - a lookup to determine if the address was allowed.
- wilun 9y agoI don't see where the contrary is stated; in a nutshell their architecture is not sensible and deeply flawed in regard to security, if they can't check that without throwing all the perf out the window.
- JoeAltmaier 9y agoNo, my point was, AMD performance in this situation may simply be worse because they didn't have time to implement this efficiency. Not because AMD was somehow prescient about the security issue.