CPU vs. ASIO Performance: Why is the performance meter maxed, but CPU not?

Cubase
16
  1. His reasons for the buffer size affecting performance are wrong. The reason is the overhead of processing each buffer is amortized over fewer buffers at a smaller size. His “window of opportunity” idea is pretty funny though :slight_smile:.
  2. His overloads are transient. They occur less than 100% of the time. That means load values displayed in his meter, which are sampled over a period of time, will be less than 100% even when cpu overloads occur.
  3. The plugins in his test run in a completely different manner when rendering for export due to different streaming requirements in that mode. So he can’t use that to compare the cpu load in those two different scenarios.
  4. I don’t know where to begin explaining his incorrect reasoning in assuming cpu overloads generally experienced by users are due to reasons other than cpu capacity. Sure, there are unusual cases where that’s true, but that’s, well, unusual.
  5. He seems to completely miss the point that the scheduling of multiple cores makes it difficult if not impossible to draw the inference he draws about whether he has sufficient cpu capacity. All it takes is one thread on one core missing a time slice schedule to get an overload, even though that core may be under-utilized over a span of several hundred msec.
  6. His swapping out the boot drive example makes no possible sense. There should be no I/O at all to that volume during his test. He should have realized that and investigated why he got unexplainable results, instead of presenting it as evidence that his cpu capacity was not significant in handling the processing load. I suspect there was something else happening that he overlooked…perhaps he’s encountering pathological paging for some reason. Whatever it was, it was almost certainly something specific to the use of VEPro.

I think the bottom line is: he is providing an explanation for a rather unusual experience, one where a machine with a more powerful cpu doesn’t outperform an less-powered one when using VEPro. Somewhere during the video, he turned that into trying to explain why, in general, the performance meter is maxed, but the cpu is not. Those are two very different scenarios. His explanations for the former do not, in general, explain the latter.