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

cmf0106

Distinguished
Aug 17, 2008
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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
 

cd14

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Mar 29, 2006
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18,680
Blend is stressing the RAM. Back up on your timings. Set it on auto in the BIOS so that it compensates for the speed.
 

vinegarjoe

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May 9, 2007
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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.