Hi again.
I'm not sure I've got much more in terms of knowledge to share, but I do have more questions - and a little bit of data.
First up - I ran a couple of tests just to get an idea of how powerful the mac mini was in terms of DAW performance. And to see what multi-cpu settings inside nuendo were doing.
Turns out the little computer does quite well. Easily runs 64tracks of audio with low (ish) buffers. Multi-cpu performance definitely helps, as does switching audio priority to "boost" in nuendo. I'll try graph the numbers at some stage - but it certainly showed shortcomings running low latencies with the firewire interface. (MH2882 expanded connected directly to the mac mini). Around 256 to 512 buffers, the CPU performance was reasonable, and I could really start loading up virtual effects quite well.
Just a note - even though these are macs, nuendo still refers to the audio performance as ASIO performance (!). The asio performance seemed to roughly mimic the CPU readings I was getting thru "at monitor" although seemed to be 5 to 10% more, and also jumped around a lot more. They got more stable as I set higher buffers on the sound card, under fairly heavy load.
But really - this wasn't the point, other than being interested in seeing if nuendo made use of all 8 cores (quad core i7 2.0ghtz, but with HT - so 8 cores visible to the OS)
It does - but it uses cores 1,3,5,7 a little more than 2,4,6,8 - for whatever reason. More on this later.
Now. To testing VEP / Kontakt on the mini, slaved to my mac pro. This is where I'm stuck. I just can't seem to come up with a test that will give me meaningful results.
What I'd like to be able to do is keep loading kontakt up with sample instruments that are exactly the same - but unfortunately kontakt is too "clever" for this, and doesn't re-load the samples when you load a second copy of the instrument. So, to stress test, you seem to need to just keep loading different instruments. However, because these are different sample sizes, its very hard to give accurate answers to what is going on.
Can someone suggest a way of doing it? Can anyone think of a test worth doing that will get valuable data?
Now - some things I did notice.
Using 4 cores in VEP, and 4 cores for Kontakt, and having 2 copies of kontakt5 open still only saw cores 1,3,5&7 being used.
Turning on 8 cores in kontakt, and leaving VEP at 4 cores, saw 1,3,5&7 being used the most, but 2,4,6,8 being used at around 25 to 40% the amount of 1,3,5,7. I didn't get close to maxing out the CPU - but I was not using full on sample instruments. The problem being these more "CPU intensive instruments I have tend to eat ram, so I run out of ram before the test is really significant.
I'm thinking I might just hold off on any more tests until the ram arrives - which could be a week or two (its coming from the states)
But ANY thoughts on actually creating a meaningful test would be much appreciated. I'll also attempt to create some sort of test for East West instruments, and Spectrasonics Instruments.
(For giggles, I loaded Alicia Keys (quite a big library) and studio drummer at the same time. I was getting dropouts on all buffer settings with just those 2 instruments. However, RAM usage was at 99% - and CPU wasn't so high - so I don't think I was reaching CPU limits.)
There is loads more to be learnt, and I feel like only the surface is being scratched.
Cheers, Brendan.