I like a lot of guys have always suffered some sound hitching in Source based games, Parnic asked users willing to try the following steps http://developer.valvesoftware.com/wiki/Stuttering
to povide some feedback so here I am.
First I guess you want system specs:
2Gb DDR 400 2-2-2-5
X-Fi Sound Card
Dual Leadtek 7600GT Extreme's in SLi
NF4 SLi MoBo
I tested every suggestion on that page, results as follows:
mat_forcemanagedtextureintohardware 1 (has no effect on the game at all) left it on for sake of it.
mat_forcehardwaresync 0 (not seen this one before - might be good but I need to do more testing tonight)
snd_async_fullyasync 1 (caused horrible sync issues - not advised at all)
cl_forcepreload 1 (has no obvious effect on anything)
sv_forcepreload 1 (again has no effect)
cl_smooth 0 (no effect)
snd_mixahead (value of 0-1 in tenths) (anything above 0.1 causes a delay on audio events and it does'nt help the hitching) setting this to -1 however may well help me, again I need to test this further tonight.
mat_loadtextures (this stops the hitching completely) also turns the whole game pink and black.
My page file usage was consistant thougout testing, I have'nt tried switching this off yet though.
I have PCIe GPU's so PCI latancy and AGP aparature are meaningless.
All drivers, fireware & bios's are upto date, I have access to NVIDIA's developer website and as such am often testing/running BETA drivers well ahead of the current public releases.
Harddrives are setup as fast as can be and are all defragged every other day.
Audio Codec priorities have been changed as suggested by Valve - this makes no difference.
So to summarize there are two console commands that may help, they are snd_mixahead -1 & mat_forcehardwaresync 0 but I need to start a new game and run through a good chunk tonight to see if there is really any difference.
With HL2 the only thing that ever made any difference for me was the recent patch that supposedly fixed it, it "mostly" fixed it in my case. I would think we are at the mercy of a code update from Valve/Ritual to bring us in line with that HL2 patch before things start to get much better.
If you have any questions or want me to test anything else please let me know, I'll update this post with tonights results when I can.