Bumping this old thread. There does seem to be something weird about the way Cubase 7.5 64-bit allocates the workload that causes high ASIO performance than other DAWs.
In theory it should be perfect as Cubase now spreads the processing load evenly across all the threads (real core and hyperthreaded ones), but in reality the ASIO performance can be very hit and miss depending on the plugins used, how many, how they're rooted but especially the single load from one plugin.
It feels like Cubase definitely favours lots of lower cpu plugins over a few power hungry ones.
Take for example U-He Diva. In divine mode on my i7 4790K, setting voice count to 16, if I go beyond 12 voices the ASIO performance meter overloads causing distortion, but task manager is only showing 12%, and showing it spread evenly between all 8-threads, so its not like its overloading a single core (or task manager is lying?)
If I engage Divas internal multiprocessing, Diva spreads the load across 4 of those threads and now the ASIO performance meter is only hitting around 25%
However, if I don't use Divas inbuilt multiprocessor function, but I only play 6 voices instead of 16, but create another 2 instances of Diva, same settings divine mode again 6 voices each. Cubase handles this ok.
The ASIO meter is still fairly high , around 55% average, up to 60-65% realtime, and Task manager is showing 22% total cpu usage.
So spread across 3 instances of Diva, Cubase handles 18 voices, but completely falls apart trying to do 16 voices with a single instance. Even with the 3 instances, ASIO performance is half as good as actual cpu usage.
Sometimes it is possible to get the two fairly even, ASIO performance 80% cpu usage 70%, using more plugins spread across different channels.
It's just a shame that Cubase 7.5 engine doesn't seem to be so well optimised for single super power hungry plugins. This is where certain other DAWs have an advantage I think.
I'm going to be trialling VE Pro 5 soon, running it on same machine into Cubase, it'll be interesting to see how that plays out in terms of ASIO vs CPU performance.
Win7Pro 64-bit, i7 4790K, 32GB 1866mhz CL9 RAM,Asus Z97 Pro Wifi, 4xSSD, MSI GTX750ti OC
RME UFX, Lavry DA11, PSI Audio A21M
Cubase 7.5.2 64-bit