computer locks up

[gcaldani]

Well, yes, you should hotwire it but i think the software monitor should be enough.
Anyway the 3.3 òome is the very important thing as i experienced a PSU that started to give only 2.5 at one point and i had my vidcard turned off exactly as you are experiencing (that was even more subtle, because my old PSU was starting at correct 3.3 losing voltage over time, so my system was working well till the system start stressing the power).

Another thing that comes in my mind and that can help to be really sure the problem is related to the vidcard:

VPU recovery is an internal ati tool that turnoff the videocard in case of any problem that could potentially damage it (ie: overheating)

I think you can safety turnoff it at least one time and see: if the problem is related to the videocard you will still have a lockup but the display should not be turned off, just everything frozen.

Anyway, would be wise to have a sensor monitor running, just in case you have no locksup (that can be dangerous because if VPU turnoff the card there is a reason) and eventually turnoff your pc if u see anything not correct in the sensors.

A question jumped just in my mind: are you really sure the system lockups?

I mean: is it possible that the display turn off but the desktop is still there (it happened to me in the past). To check this just configure sounds for any windows button click and, once you are in front of the blank screen, press the WIN key. If the desktop is there, you will hear the sound of the Start menu popping out. In this case you can safety reboot the system.

Not sure i have anything else to suggest to understand the problem other than asking a friend for another videocard to see what happens.

[gcaldani]

I googled how to disable VPU Recovery and it says I do it in the Catalyst Control Center but there is no option anywhere (even in advanced mode)...

Download Aty Tray Tools (ATT) from http://www.guru3d.com. In the standard tweaks you will find the option to disable VPU Recovery.
ATT is a 3rd party tool that substitute CCC, but you can use it with CCC installed as long as you don't run it after you did the change (for the test).
Once you have done the test you can decide to continue using it (but you have to remove CCC in this case) or just remove it.

Check in guru3d ATT forum the version of ATT you download, as a free tool there are different versions around. Latest version should be 1.6.9.1433.

[gcaldani]

Cross your fingers and enjoy the life in Atys