I've never overclocked a cpu before so I guess I'm hesitant. What are the risks vs rewards?
Almost no risks if you keep the voltage below maximum specs and maintain reasonable temperatures. Q6600 B3 @ 3.2ghz and G0 stepping @ 3.4ghz are most likely doable. Just get a $30 Cooler Master Hyper 212+. Overclocking the Q6600 is the easiest in the world on your board:
1. Flash the board to the latest BIOS from the corporate website using @Bios flashing tool.
2. Set PCIexpress frequency Fixed to 100.
3. Disable all power savings features (C1 states, EIST).
4. Relax ram timings to 5-5-5-15 and increase voltage to 2.0V
5. Increase CPU voltage to 1.425V.
6. Increase MCH and FSB voltage +0.1V
7. Set a lower CPU Ram Ratio (i.e., 2.0 is the lowest on Gigabyte boards) so that your ram isn't running out of spec.
8. Set CPU FSB to 378 FSB for G0 stepping for 3.4ghz, or 356 FSB for B3.
Do stress testing using Orthos, LinX and then go back to #4 and #5 and find the tightest ram timings and the CPU and Ram voltages that ensures stability. You are done.
I am currently playing sc2, plan on getting Civ 5 and I am mainly looking to upgrade my gpu for FFXIV mmo.
And it also looks like FFXIV will favor nVidia GPUs as well (could be wrong here but its just what I read most recently). Don't have a clue about about Civ 5. But from the games you listed it seems like your best best is to go with a GTX460.
Sorry, nVidia, especially the 460 is
FAR outclassed by the 5850 in FF14. I mean it's probably the WORST recommendation for that game.
GTX460 is not even a contender. It is 46% slower than ATi 5850 in FF14!
http://www.xbitlabs.com/articles/video/display/nvidia-geforce-gtx-460_15.html#sect2
Even when overclocked to 800mhz, the GTX460 1GB trails the stock GTX470 and 5850 by a whooping 23-25% in FF14.
Also, don't forget you can overclock 5850 to 900mhz+. It will be EVEN faster than the 5870 which is an unbelievable 72% faster than a GTX460 in FF14.
The performance in SC2 will be similar, however:
http://www.xbitlabs.com/articles/video/display/starcraft2-wings-of-liberty_5.html#sect1
Regardless, since you haven't overclocked your CPU, you are unlikely to overclock the GTX460. Since GTX460 is only viable over the 5850 when you consider overclock, you should be comparing $260 GTX470 with $260 5850 not GTX460 with the 5850. GTX470 is at least 40% faster at stock speeds over the GTX460 in FF14 and faster in SC2 than both the 5850 and 460. However, it runs louder and consumes more power than the 5850, but it is faster by 7-10% depending on the games.
If you don't overclock the CPU, you will be CPU limited in SC2 and a ton of other games. Personally, 460 is a non-contender since you mainly are looking at FFIV where it can only manage 40 fps @ 1920x1080.
Add to the fact that ATI cards are less sensitive to CPU speeds, and my vote is the 5850!!!
P.S. just for reference, if anyone is curious how badly an overclocked 5870 thrashes a GTX480 in FF14, follow this
link