New OC passes small FTT, but fails Blend in prime95, whats the Culprit

First thank you for taking the time to check this.

I am currently running with these settings trying to achieve a 3.8 OC on my q9550 (stock 2.8).

FSB- 1800
CPU-8.5x
Link and Synced
5-5-5-15-2T

CPU- 1.375v
FSB-1.325v
mem-2.1v
SPP-1.45v
MCP-1.6v
SPP-MCP- 1.4v

Idle temp: 38
Load temp: 55

With this the system performs marvelously in Prime95's small FTT stress test. But when I try to run a prime95 Blend test, it only
lasts about 3 minutes until encountering a fatal error typically on thread 2 or 1. The error reads "fatal error rounding was .5,
expected less than .4"

System Specs:
Intel Q9550 2.8
Heatsink: Tuniq Tower
EVGA 780i SLI FTW
Nvidia GTX 280 x2 SLI
G.SKILL 4GB (2 x 2GB) DDR2 @ 1066
SILVERSTONE OP1000-E 1000W ATX 12V 2.2 & EPS 12V
Windows Vista 64 bit
5 answers Last reply
More about passes small fails blend prime95 whats culprit
  1. How long did you run the smallfft test?
  2. About an hour, but thats alot longer compared to the 3 minutes it lasts on blend
  3. Hmm. Try upping the voltage by 1 notch.
  4. Blend is stressing the RAM. Back up on your timings. Set it on auto in the BIOS so that it compensates for the speed.
  5. Yea ram is probably the culprit. You could try running memtest for a few hours to verify that though. Also, 1hr is not nearly long enough for a final say on whether your system is stable or not. You need to go for at least 6-8. Preferably get a 24hr test in there as well.
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