you can try using my kernel howto (see signature), it might get a little better. but keep in mind that you don't have a recent cpu and only a single cpu core. also amd cpus are not very good for game servers (usually).
that's only important for disk IO, and disk IO is evil in any case for game servers (seek times are usually in the order of 10ms, that's way to long to keep like 1000 fps). so basically we trust that srcsd/hlds doesn't need to do disk IO in the running game. else we have lags in any case, you could only try to minimize the lag...
tsc is very fast, but not as accurate as hpet. Both ones are completly changed.
tsc > very fast because its implemented in most of the newest Intel CPUs, but not 100% accurate. You dont need to switch it on, its normally the standard timer.
hpet > its slower because its implemented in most of the newest Intel Chipsets (and other) but very accurate. You have to turn it on in the bios. Normally you have to force it > clocksource=hpet (kernel parameters)
If you want very good results you can use both it doesnt matter.
Some voices told me hpet is better, but i have a lot of systems now running with both > i found out no clearly different
activate acpi and its timer (in BIOS and kernel) and use acpi_pm. tsc is not really good for game servers... and btw: hpet is on modern systems (especially on recent kernels) not really slower than other clock sources. that was only valid when hpet was very new...
BehaartesEtwas: i think thats untrue. I got with my newest system (AMD Shangai Dual Quad Core) only 960-970 FPS. This AMD dont have hpet, only acpi_pm, tsc and jiffies. I tested "acpi_pm" hopefully it would give some more stable/higher FPS. result was > 500 FPS :-)
Ok i tried only one test, with no more tests, perhaps you have an other idea.
But the most of tutorials and your own ones recommend hpet, there is no word about acpi_pm.
Here you can read something about the timer: http://wiki.debianforum.de/KernelTimer
I think the best choice is hpet because its more accurate.
matte563:
The older AMD64 versions have Hpet. The very old ones do not have it and the newer one, too.
In the newest Intel CPUs is this option standard.
Peter: You shouldn't conclude from your system to all ;-)
enabling acpi is generally a good idea, as it will disable some "system management" interrupts (don't remember the right term) which could disturb the server, as acpi offers an alternative (more modern) way of handling those events.
the link you give doesn't tell me anything new. it basically says, TSC is not good, but HPET is the best. acpi_pm in somewhere in between and thus the best option if HPET is not available. that was my statement ;-)