Ok, the gpu looks legit. In Nvidia Control Panel > Manage 3D Settings, is power plan on either Adaptive, or Max Performance?
Also, I now I believe I've figured out why it keeps crashing!
1)Your current 12GB memory configuration has you mixing DDR3(Hypertec) and DDR2(Patriot)! They have to be the same type. You can do 2x DDR2 or 2x DDR3, but not combine them.
2)An old motherboard like that isn't going to have a wide range of supported memory modules, and 1, or possibly BOTH sticks aren't officially compatible with that motherboard.
-Test each stick separately - NOT WITH MSI KOMBUSTOR. https://www.memtest86.com/ (requires a spare usb drive)
-If you do not have a spare usb drive, then get Prime95: https://www.mersenne.org/download/
When you first open it up, click Cancel, then click Advanced, and make sure 'SUM(INPUTS) error checking' is checked.
Go to Options > Torture Test, select Blend Mode, and hit OK. Let it run for at least 30mins. Prime95 is usually pretty quick to spot errors, so it might not take that long.
-Another alternative is AIDA64(limited free trial). In the stress test options, have ONLY the memory test selected and run it.
[Selecting and running multiple tests will cause cpu temperatures to spike hard!]