Why can I never go above 50% processor with a low buffer?

[alexaaz]

Hi,

I have a dual 2.8ghz Intel Core 2 Duo running OSX 10.5.7 with an RME Fireface 400. I've recently started pushing my processor harder using soft synths such as Alchemy. I like to keep latency low but the moment I go above 50% with a buffer size of 128 I start getting drop outs. If I change the buffer size to 1024 I can add loads more plugins and I can push processor usage *much* higher without drop outs; I just got it to 75% and no drop-outs. I can also run a lot more plugins because of the increased buffer size.

Why is there a bottleneck that stops me getting above 50% cpu with low latency?

Is this a Mac OSX thing? Does this happen in Windows? Could it be my audio interface? Is anyone able to get above 50% with no problems with low latency (128 samples)?

Thanks,

Alex

[longjohns]

50-60% on the ableton meter is about normal to start getting glitches

just re-calibrate your thinking around that number

[alexaaz]

lol surely they should recalibrate the meter?

[locojohn]

lol surely they should recalibrate the meter?

Try rather increasing buffer size, say, to 192 or 256 and see if drop outs still occur at 50% CPU usage.

Andrejs