[linux-audio-user] latency issues

two years ago i did a bunch of testing on latency to find the best kernel and patches for my system, and got some damn good results with several kernels (the best being 2.4.12-ac3-pe (alan cox's patch and pre-emptive kernel patch using alsa on suse 7.3 with gcc 2.96 20000731). i now have a new computer with gentoo linux and alsa 0.9.6, and can only get 16 ms latency with perfect results. same soundcard - m-audio audiophile 2496 (ice1712). i've used kernel 2.4.20 with pe, ll, and some other options, compiling with gcc version 3.2.3 20030422, and i get the same result with all of them (as well as without pe or ll). does anyone know what the problem could be? alsa version? gcc version? kernel version? hardware (eth0 and soundcard share irq - never thought to test without eth0 loaded)? i'd like to get latency under 4 ms. thanks for your input, dave