Re: [LAU] Ubuntu Hard real time kernel (2.6.24-21) poor performance.

After a number of years of making successful music recordings using a combination of rosegarden and ardour on my Ubuntu Dapper Drake system, and my home grown real-time kernels, I thought it was time to upgrade to Hardy Heron and use the proper real time kernel that the experts had built. What a disappointment! I have an internal pci sound blaster live card (emu10k1 chip set) and a M-audio audiophile USB sound module. On my dapper installation, which happened to have 2.6.22.1 real time patched kernel (the default ubuntu kernel was 2.6.15), I could get latencies as low as 1.5ms (32 frames/period) on the sound blaster and 2.7ms ( 64 frames/period) on the USB Audiophile with very few xruns; so few xruns that I used to wonder why people posted to mailing lists/forums about the problem. With the stock Ubuntu 2.6.24-21rt kernel the sound blaster gives xruns every few seconds with no load (no recording and no playing back) at 23ms latency (512 frames/period) and the Audiophile struggles at 43ms ( 1024 frames/period); I am getting xruns every 10-20 seconds. Infact the rt kernel gives little, if any, improvement over the generic kernel.