Q9550 is unstable when oc'ing

chriscornell

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Jul 27, 2009
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Hi People.

So, I recently got a Q9550 (stepping A, Rev E0) and a XFX nForce 750i SLI motherboard to plug it in. Installed it with a Zalman-cooler (don't remember model, one of those big copper mothas 95..something). The cpu i stable with a V-core as low as 0,90V and load/stress-temp is around 45c - All this is good.

The problem is, that the damn thing won't overclock. Not even 2,9Ghz is stable?

My first thought was that the motherboard was sucky and that the chipset needed more power
- I installed my old E6750 which runs with the same fsb as the Q9550, and the beast went past 4Ghz without problems, feeding the chipset standard voltage and only giving the cpu 0.5V more than stock.

So the chipset is fine, and the motherboard is a good oc'er.

Reinstalling the Q9550 resulted in the same crappy stock-like freq. and I'm lost?

My mashine consists of the following:

Q9550 (surprise)
XFX nForce 750i - flashed with the latest rev. BIOS
Zalman something 120mm copper cpu cooler
Zotac GTX 260 V2. gfx
Creative Xtreme Gaming S.B.
Patriot Warp V.2 SSD system-drive
Western Digital Caviar 500Gb WD50 HDD
LG Blu-ray/DVD-combo drive
2x 120mm Antec tri-speed casefans
Chill Innovation 520Watt, 80% efficiency PSU - link: http://www.chill-innovation.com/products/products.php?kategori=&products=4

So my questions are:

Is the PSU too weak? My system shouldn't consume much more than 400W max. when running 3D-applications.

Is the n750i just to crappy at overclocking quadcores?

or is it something else?

I really want to squiize this here cpu, as the rev. and stepping are in the good end and considering that it runs stable at 0,90V - right now my E6750 running 4Ghz is faster, and that really sucks as I'm often rendering film using Avid and I often use Photoshop - both programs benefit from more cores. I play games too ofc.
 

ptizz

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Feb 1, 2010
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I have a q9550 in a xfx 680i lt mobo. I read after i bought the q9550 that my mobo didn't support 45nm processors. I flashed the bios and and the q9550 worked just fine. So oc'ed of course and I am running stable at 3.6Ghz. I mean it isn't awesome but hey I can't complain. I believe that 750i was designed with 45nm in mind so i think you should be able to at least get as far as I have.
 
Goodluck with that. I mean obviously you can't expect miracles but it seems odd that it wouldn't go even 100Mhz over.

I know my own struggles with 3.6 and anything over is a no go but 3.4 was okay with a bit of extra voltage.