Actually this is an easy question.
Ubuntu > Debian > CentOS
1)
For a person who is an experienced Linux user, s/he would already have a preferred distro, and would know enough to twist things around to suit his or her needs.
Thus the answer to which distro to use, would be any distro.
2)
SRCDS Linux is portable, that you can use the same copy of SRCS Linux on a different machine, by simply copying the files.
Thus continue from my point #1, for experienced Linux user, it would be better to find out the results by running the SRCDS Linux on different distros.
3)
For a new (or average) Linux user, who doesn't know enough about Linux, it would take a while before s/he would have learnt enough to twist things around. The important thing for his or her, is the
"out-of-box" experience, because s/he is already paying for the dedicated box, and need to be able to use it now.
4)
So for this member (I assume s/he is a new Linux user), my answer would be:
Ubuntu > Debian > CentOS
5)
I am still learning to use Linux. For my web server, I use CentOS, because that seems to be the preferred distro. For my home box, I use Ubuntu, and I have been using it to host my testing SRCDS Linux for about a year.
Yet occasionally after a SRCDS update, I would get issues like segmentation fault, unable to shut down the SRCDS by using "exit" or "quit" and had to use "ctrl+c" instead.
Therefore, after I got my dedicated box, I tried CentOS, as I assumed it would be a better choice for a server. I tried CentOS 5.3, 5.4, i386, x86_64, and the "out-of-box" performances were horrible. Of course for those CentOS guru, they know enough to twist it for a decent performance, but I don't know how to do that.
Also, I wasn't able to compile a custom kernel, even by following the official wiki (
link).
(By the way, I like the official CentOS wiki more than the Ubuntu's one, because it seems to be more accurate, up-to-date, and easier to follow)
I checked many CentOS/RHEL forums and mailists, and most questions regarding how to solve the custom kernel issues, only lead to a dead end. Most of the time I see people saying that they have solved the issues,
by switching back to the default kernel...
6)
I have then tried Debian, and was able to compile the custom kernel, yet having been an Ubuntu user, I missed those little twists that Ubuntu offers by default, so I then switched back to Ubuntu.
7)
So far with Ubuntu 9.04 x86_64 server, I haven't experienced any issues.
8)
From my readings, kernel from 2.6.30 and up, yield some good increase in general server performance, which also seems to work for a SRCDS server as well.
9)
I still use CentOS for my stats hosting, forum, fast download, CMS, just that for SRCDS Linux, at the moment, Ubuntu/Debian is the better choice for me.
10)
Last to mention, be sure to follow BehaartesEtwas's Linux Kernel HOWTO!, and use his FPS Meter. They helped me to optimize my server performance (Thank you BehaartesEtwas
).