AMD Corporate VP David McAfee recently addressed the matter in an interview with Quasar Zone. When asked about AMD's power consumption versus operating temperature compared to the...
Giving individual cores the ability to boost as high as possible means that in scenarios where multi-threading doesn’t scale perfectly, you can still squeeze as much as possible out of the other cores. Because the thread that bottlenecks the most can be run as fast as possible.
Or in other words: Limiting the top boost clock by 5% will effectively slow the entire CPU down by 5% as well.
That’s why if you want to limit the CPU power draw, you should do it either via the power limit, or by reducing the throttling threshold. The latter can give you better performance in “race to finish” situations, where you only need a short power boost to finish a task, but it’s less consistent.
Wouldnt reduce the clock speed a little get the same thing as well? It is exponential rate anyway, that last 300-500MHz is generate most of the heat.
Thing is a big 20% IPC increase sounds way less impressive if it comes with a 5-10% clock speed decrease.
But that’s probably like +40% perf per watt, which does sound good.
Giving individual cores the ability to boost as high as possible means that in scenarios where multi-threading doesn’t scale perfectly, you can still squeeze as much as possible out of the other cores. Because the thread that bottlenecks the most can be run as fast as possible.
Or in other words: Limiting the top boost clock by 5% will effectively slow the entire CPU down by 5% as well.
That’s why if you want to limit the CPU power draw, you should do it either via the power limit, or by reducing the throttling threshold. The latter can give you better performance in “race to finish” situations, where you only need a short power boost to finish a task, but it’s less consistent.