My system would pass Memtest for days on end with no problem. The only test I found that gave errors in parallel with TI9, as I said earlier, was Prime95 (under Windows). I ran the blend test and it would rarely get past 5-10 mins without a rounding error. I suggest you get Prime95 - you might need to run the custom test (instaed of blend) and reduce the memory usage parameter a little if you get disk paging with the default blend test. If you are unfamiliar with Prime95 then google is your friend as there are guides about - just remember to set priority to 10 (password 9876) and select tests via the torture test menu. Best of luck.