http://www.mtm2.com/~mtmg/misc/Beta0.47_Rudee_test7.zip
New test, copy both .exe and .dll
Do them on the HDD drives.
This one is going to be a little more involved, sorry. But there is also a genuine concern that the issues you are having with the 6650 might be genuinely from your system not interacting well with the game when on the HDD (as evidenced by working fine on the SSD), having background operations (windows memory paging, antivirus etc) coming into conflict with MTM2. While AI is pretty good at doing things, it's not great at coming up with very specific edge case fine-tuning solutions and your situation might have reached the max of my understanding and I'm not able to steer the AI into finding the right way to fix it.
So do the following tests:
V-Sync off - bobsled/quid
Send over the perf, sndperf, hitch txt files
Then the same but with
V-Sync on
THEN, go to system and edit monster.ini. In the graphics section scroll down to find tripleBuffer=1, change that to a 0, save the ini and run the same tests again with V-Sync On.
The tripleBuffer thing is hopefully a way to fix your issues when running Vsync on.
And one specific test for the SDD, this one only on quid pro
V-sync on
tripleBuffer=1 (enabled)
and then one with
V-sync off
tripleBuffer=0 (disabled)