Does anyone know how high a stock e2160 can be overclocked while remaining stable and at reasonable temperatures? (W/o additional case fans - I assume having more case fans or a purchased cpu cooler would increase OC potential further)
 
Thanks

2.9 on stock cooling would be about your max. 3.3 would be about right with a bad ass cooler. Depends on the chip mostly. My e2180 didnt like to run stable over a 333FSB and with the same Mobo my e7200 runs 421 stable. Everything exactly the same except for PSU's.
 
If you tossed the idea around about a better cooler , dont. For the price of the cpu and a cooler you could buy a retail e7200 and get better results.

Ok...and is the clock speed of the CPU what bottlenecks the video card? (overclocking reduces bottleneck?)

An OC should reduce or eliminate bottleneck, yes.

If your video card sucks, then OCing won't remove any bottlenecks.

3.0GHz Is a nice medium for overclocking it as the temp does not shoot through the roof and is stable.