If you want to test your cpu or your vidcard for stability the best test is the (original/first) Unreal castle flyby. I have to laugh at so many people who think their vidcard or cpu is stable without at least looping the flyby minimum 100 times. This will basically kill anything that is not stable ...even the Q3A exec demoloop doesn't do this much damage b/c of the pause to reload between maps.
What usually happens is you will get kicked & end up with long error message if the cpu is the problem, or if the vidcard is overclocked too high the system will lock.
My V5 will run forever at 183, but anything higher and it will invariably lock ...just give it time. Unreal flyby will eventually bury anything if it's too far overclocked/overheated
edit #1 : you don't need to install the full game ..just like 50mb of system files and run it off the cd
edit #2 : I would be interested to know if your card will run 194 overnight with the case closed and looping Unreal ...if it does you are a hero
edit #3 : that is a sweet mod ...maybe the best I have ever seen on a V5 ...I don't doubt that it will do 194mhz ...nice job!