BSOD 0x00000003b

it's not overclocked, idles at 53C and load at 70-80C, so should be safe enough.
probably the drivers, i'm going to reinstall the drivers later at night.

53C idling is not particularly great. 70-80C under load is going to trip the heat warnings, unless you've disabled them. I'm not into trying to reach absolute zero (adequate cooling is... adequate), but those numbers are in the "dangerous" category.

Try opening the side of the box and pointing a mains fan straight into the motherboard. If that greatly reduces the frequency of these crashes, it's obviously heat-related.

already using 2 x 12 inch fans blowing to the card from side panel (CM stacker 830)
aircooled room in a tropical climate.
it's below average temps for 4890 over here.

unless you're talking about CPU, my CPU idles at 33C and tops at 58C

djbb said:

already using 2 x 12 inch fans blowing to the card from side panel (CM stacker 830)
aircooled room in a tropical climate.
it's below average temps for 4890 over here.

unless you're talking about CPU, my CPU idles at 33C and tops at 58C

I thought you were talking about the CPU. In any case, you might want to try the mains fan for a while, just to check whether it makes a difference. All 12V "computery" fans are comparatively smeggy when it comes to volume of air moved, almost irrespective of their diameter.