I signed up on this forum really only to reply to this thread, although I will likely stick around.
I am running an AMD Opteron 165 @ 2610 MHZ (currently). The Opteron 165 was the primo overclocking chip for a long while before the C2D came out, and I used to run it at 2.8GHZ on stock cooler (got lucky, but after time thermal migration or some such caused me to lower it a bit, not a big deal).
Anyways, I still haven't upgraded mobo (DFI) and CPU because of a combination of massive initial overclock, declining interest in gaming, and finally a year ago a switch to linux. It just still works fast enough for me, and really it is quick. I did upgrade my video card a few times however (currently on an 8800GT with an overclock). Yeah, that is old too.
I just wanted to say, that my switch to linux, after a few unhappy stints with Ubuntu, is probably the only reason I still use this 5 year old PC. Otherwise I would have shelled out lots of money to keep current with Windows.
I now use Arch Linux (x86_64 version). www.archlinux.org. The best place to start is the Beginners Guide on the Wiki, and the Wiki is your best friend and of excellent quality https://wiki.archlinux.org/index.php/Beginners_Guide
I would recommend this linux to anybody who has previously tried Ubuntu for a few weeks but was unsatisfied. You MUST configure the system yourself, but that is what makes it so great. If the fonts bother you, install the windows fonts and change the aliasing options. Whatever it takes, it IS possible and you will learn lots. You get a fast, custom system, and learn the basics of linux in a way that Ubuntu will NEVER teach you. The Arch wiki and AUR (custom software installation) are great. Documentation is well above average. I cant recommend it enough. I tried ubuntu a few times (various flavors), but something would always screw up and a solution was hard to find. Google searches are futile with Ubuntu because there are so many similar (but really unrelated questions due to past versions), it sounds like your problem, but really isn't. With arch, just consult the wiki (in most cases, always try it first), or the manual (man command), or as a last resort the arch forums which are great. Arch also uses some aspects of BSD that make it easier to configure in relation to a standard Linux, although Arch is Linux. Hard to explain, but if you use it you will see (rc.conf for starts).
I am surprised that my system still runs after running it overvolt and overclocked for so long, and that my three HD's averaging about 4 years old now are all still working, but I really see NO REASON to upgrade at this point. This system is so fast and never locks up except when I boot into XP. XP has a tendency to just become unresponsive from .5 seconds to forever at times (even at stock clock and volt), so annoying. Arch never does that. Windows 7 or Vista would be even worse than XP when it comes to speed.
Sorry if this sounds like a true-believers rant, but I have had a great time with Linux after trying Arch, and it has taught so much to this 7+ year IT tech. You can do so much with shell scripting, and compiling programs from source, or even modifying programs before compilation is not as hard as it sounds. It has been less than a year since I started this, and really I am quite comfortable with it now (I was very intrigued after a day with arch, and completely sold after less than a month of hard work). At that point I even turned my 4+ year XP install into a virtual machine with Disk2vhd, although I will admit that I recently re-partitioned a drive to install XP and dual boot again. Don't worry, I ain't switching back to Windows as my main system any time soon...
Really, it is all about the distro, try more than one. I would recommend Arch, but each to their own. You WILL have to spend a week or two configuring to your hearts desire, but that is the point!
If gaming is the vast majority of your PC use I think it will be hard to develop the interest to do what I have. I still recommend trying various distros in a dual-boot for anybody though. You can learn a lot. Ubuntu was a good start, but so much more is out there.
Edit: For clarification, I use Arch X86_64 with Openbox as my Window manager (although you can use Gnome, KDE, or other desktop/window managers). You could even make it the same as Ubuntu in day to day use, but why do that? My preferred file manager is a combination of Thunar and Worker (I love Worker for the scripts you can make easily with it).
Since there was recent question about Wine, I will share my experiences. The most recent game I care to play is Stalker: COP. It runs in Wine fine, as long as you do not care about Dynamic Lighting (I bet you do). This is because of a bug in Stalker, supposedly, but the Wine folk are not interesting in making fixes that only apply to one game, so the only fix for now is to play at a graphics level that corresponds roughly to DX8.
Either way, it runs a bit slower in wine. That is just one example, I played through it in Wine in Dx8 mode without problem, but I would not count on Wine to get you through all games, it is on a case by case basis.
Dual boot with XP or 7 if you are worried.
Like I said, I don't play games as much as before. I wish Wine worked better, but as it is developed by a small team, they don't wish to make individual fixes for specific games. I do believe that the future of Linux gaming is bright, and I think that the difference between linux and windows gaming will diminish as (frankly) high-end windows gaming diminishes.
Edit: if Photoshop is the main reason that you don't like linux, make an XP VM (or vista, or 7) in Virtualbox and run it in there. You can even run it in seamless mode where it appears as a regular window in your Linux desktop. It does take time spent in configuration, as with anything in Linux, but after a few months of config I spend very little time doing that kind of crap and I have a system that works how I want it to. Also, Adobe Flash works fine now in Linux, even in X86_64 (for me at least), I know this has been a long standing problem and it was a problem when I started. It has been working fine for about 6 months now though, I think they have it worked out. Hopefully Flash will be a non-issue for everybody in a few years, and it can join RealPlayer in the cemetery... lol
we have a devoted linux section, that you can find at:
I myself, use Ubuntu for my desktop(with kde workspace, kubuntu i dislike and there is a difference trust me ), slackware headless (no gui or monitor, ssh into when i need to do work ) for my file server and i use my laptop as a test bed for distro's, right now it has crunchbang on it.
I keep a copy of windows always installed, just incase, typically for web site testing (as i'm a website designer, and need to make sure things work correctly in the IE, i have xp loaded in 3 seperate VM's, one for each flavor of IE from 6 to 8, but since 9 is only available to 7...guess i will need to add one more, will be dropping support of IE 6 and 7 this summer tho, yippy! )
I like ubuntu the best i do believe, the reason i like it, it as advanced as you want it to be, it is fully capable of doing what the other linux distro's do, nothing really stopping it i like it cause of the repo's, yes they are a bit out of date compared to those of arch, but what they have in them is unmatched even by rpm repo's. i would run debian instead, but it is pita to run a mixed-repo installation of debian (dipping into testing and unstable repo's, and even using ubuntu debians or repo's, some enjoy the challenge, i personally don't.)
ubuntu's community is filled with noobs, one of the main reasons it is hard to find good "support" when you need it, typically you can find good support on linuxquestion.org, you can venture into debian land if you want to find help, but their community is a bit, not sure what to call them, brutish? they don't like noobs and they really don't like ubuntu users LOL.
arch i've tried, (if you can handle slackware you definitely can handle arch), i just didn't like it, there was a lot of little things i didn't like, it just wasn't one big thing, the lacking in their repo's was the biggest thing, and aur to me wasn't an acceptable add on, i found numerous problems using aur packages, and then updating my system (lot of the time it was dependency issues, they were easy to fixing, but annoying to have to fix them everytime running the update command.) i did get a hang of altering the PKGBUILDS file and storing my own locally vs using the ones in aur, the other problems i had with it was repositories fizzing out, i would choose the closest and fastest ones to me, and within a month i would be replacing them, cause they either stopped being arch repo's or they stopped updating (the first time this happened, was installing, and i chose a mirror in the mirrorlist, and it was 8months to a year old, and it installed all old packages, when i caught the error, i switched to a new repo, and did a system update, and it boinked the system, had to reinstall, which to me was unacceptable for me to take it serious as a committed distro, some suggested i should have done a netinstall vs a disc install, and i had done a netinstall when this occurred...)
It is a good distro, it just wasn't for me, and arch uses a *BSD style init, (it is different tho, slackware uses a true *BSD style init) which is what you were looking for. most linux distro's use this, as it was taken from *BSD, ubuntu uses upstart, which is something different.