I am still pretty new to CUDA, trying to figure out what kind of application this can be used for. What I would like to do is realtime audio/synthesis under MIDI-control, so I started out studying what kind of timeframe would be possible? Ideally kernels should run for (at most) a millisecond at a time to have reasonably low latencies and leave enough room to have graphics updating as well.
At first this didn’t look too good. With a plain vanilla desktop kernel, about 20% of the time was spent on uploading a small fragment of data representative of the keyboard state. Upgrading the kernel to 220.127.116.11-rt17 doubled the throughput but most importantly: Jumping out of Gnome then quadrupled the throughput? Modifying the bandwithTest to ask for high priority realtime performance shaved off yet another 20%, so now the test can upload some 10Kbyte of data in just 0.02 milliseconds rather than the original 0.2 milliseconds. That should be good enough, I think …
But what I wonder is: What is up with Gnome? X by itself isn’t degrading performance, nor is a lightweight environment like IceWM.
mvh // Jens M Andreasen
[using a silent 8400GS/g98]