Re: Core Audio & DP Performance
Re: Core Audio & DP Performance
- Subject: Re: Core Audio & DP Performance
- From: Jeff Moore <email@hidden>
- Date: Fri, 18 Apr 2003 14:30:59 -0700
My guess is that you are doing all your DSP on the HAL's IO thread,
yes? That's what the ping-ponging of the CPU load indicates to me. By
doing this, you are effectively ignoring the second processor. What you
are seeing is the IO thread running on the CPUs. But you will only ever
be using one of them at a time to do work. Your performance numbers
bear this out.
To make use of both processors, you need to come up with a scheme to
offload some of your DSP work onto another thread. How you best
accomplish this will depend on how you have your rendering pipeline set
up. You'll need to figure out the data dependancies and then organize
the work accordingly.
On Friday, April 18, 2003, at 01:58 PM, Lubor Prikryl wrote:
Hi,
although this is a bit off topic of development interests, maybe it is
important.
I tested the same reverb algorithm on various systems, the criteria
were the maximum effects before clicks appeared.
The tested plugin DS-RV1 is available with our GT Player on Apple OS X
downloads site.
Buffer size 128 samples, PC uses ASIO drivers
The result is a maximum number of processing reverbs.
iMac G4 800MHz / MOTU828 7
Silver G4 733/ MAudio Delta 2496 AP 6
Dual G4 1.4GHz / MAudio Delta 2496 AP 12
Celeron 1.2 GHz / MAudio Delta 2496 AP 10
P4 1.8 GHz / MAudio Delta 2496 AP 16
The problem of DP G4 is:
Both processors are loaded in average by the same load. But the load
is fluctuating from one processor to the second, so in certain moments
one runs with very low and the second with very extensive load.
The maximum overall load is very far from the 85%-90% of single CPU
machine (of course).
The application itself (GT Player) runs GUI (e.g. meters) in one
thread, event loop in another one, midi and audio with their
time-constrained threads. Can developer schedule threads to make
performance of both processors more "stable"???
Lubor, DSound
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--
Jeff Moore
Core Audio
Apple
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