q9550 Overclocking..

loginmytech

Member
Feb 21, 2010
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Hi,
I'm an OC noob and just did my first OC today. I raised the FSB on my q9550 to 376 x 8.0 mult gives me a mild OC of 3.0ghz.

I was wondering if you could check out my stats (in attached photo and let me know what you think). I'm curious how far I could push it with this board and how to adjust v-core.

MB: gigabyte p35c-ds3r rev 1.0
ram: 4 gb g.skill ddr2

Let me know if anything on this looks out of whack. Also I ran Prime95 for an hour and hit 55C on Core #2 as my highest temp.

Please let me know other things to tweak and what to look for.

Thanks

4376994763_2806802958_b.jpg
 

dguy6789

Diamond Member
Dec 9, 2002
8,558
3
76
Do you have PC2 6400 (800Mhz) or higher rated ram? If you do, make sure your memory is set to a 1:1 ratio with the FSB, then you should have no problems cranking it to 400mhz FSB and 8.5x multiplier for a 3.4Ghz clockspeed.
 

dguy6789

Diamond Member
Dec 9, 2002
8,558
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Should be all you need to do. Any higher than 400 and you will be overclocking your motherboard and your RAM just so you know.
 

loafbred

Senior member
May 7, 2000
836
58
91
Your core voltage is being set higher than needed when you leave it set to "auto". It may need 1.35v at 3.4 to 3.6 GHz, but it shouldn't need more than 1.20 at 3.0 GHz. If you have a "LLC" (load-line calibration) option in BIOS, turn that on, and manually set vcore to 1.20. I wouldn't run mine at over 1.30v vcore, but I'm the paranoid type.

Be aware that you will now be venturing into the unknown, and O/S corruption can easily happen. I always disable my hard drive, and boot from a "UBCD" CD or DVD. Google UBCD, download the ISO, and burn it to either a CD or DVD. When you boot from it, you will see "mainboard utilities" or something similar. In there you'll find several stability tests. Try Memtest 86+ and Prime95. If it will pass Memtest once, and Prime95 for an hour, it will probably boot Windows without corrupting anything. Once in Windows, use the stability test of your choice, including games.
 

dguy6789

Diamond Member
Dec 9, 2002
8,558
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Your core voltage is being set higher than needed when you leave it set to "auto".

Are you sure his motherboard in particular does that?

Not saying you do, just asking, but for some reason, a lot of people on this forum think all motherboards raise the voltage of the CPU when you overclock the CPU and leave the voltage on auto. This is simply not true. There are a select few motherboards that do, but definitely not all of them.
 

loafbred

Senior member
May 7, 2000
836
58
91
Are you sure his motherboard in particular does that?

Not saying you do, just asking, but for some reason, a lot of people on this forum think all motherboards raise the voltage of the CPU when you overclock the CPU and leave the voltage on auto. This is simply not true. There are a select few motherboards that do, but definitely not all of them.

I'm just going by his screenshot, which shows Speedfan reading 1.34, and CPU-z showing 1.328. I just now noticed, though, that Coretemp is showing his VID as 1.300. I didn't know any of the Q9550's had VID that high. What would the upper tolerance be with 1.30 VID?
 

dguy6789

Diamond Member
Dec 9, 2002
8,558
3
76
I'm just going by his screenshot, which shows Speedfan reading 1.34, and CPU-z showing 1.328. I just now noticed, though, that Coretemp is showing his VID as 1.300. I didn't know any of the Q9550's had VID that high. What would the upper tolerance be with 1.30 VID?

My understanding is ideally, you do not want your cpu voltage to be as high as the VID.

It does actually look like his board is overvolting his CPU because I've never heard of a 1.3 volt Q9550 before. Maybe they are using lower grade chips with less headroom with more volts for the new 9550s.

OP should definitely manually set voltage in this case. Try 1.2 or 1.25 and see how it does at 3.4Ghz.
 

MagickMan

Diamond Member
Aug 11, 2008
7,460
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Depending on the Q9550, you can get 3.4-3.8GHz @VID (default voltage). If you want an easy OC just:
- manually set your core voltage to it's default (usually around 1.21-1.28v)
- set the FSB to 400
- run some stability tests
- and call it a day

If you're using the crappy Intel cooler you don't want to go higher than that.
 

SmCaudata

Senior member
Oct 8, 2006
969
1,532
136
Depending on the Q9550, you can get 3.4-3.8GHz @VID (default voltage). If you want an easy OC just:
- manually set your core voltage to it's default (usually around 1.21-1.28v)
- set the FSB to 400
- run some stability tests
- and call it a day

If you're using the crappy Intel cooler you don't want to go higher than that.

With my p35 board I had to bump the Northbridge voltage but I didn't have to touch the core voltage. Couldn't do more than 10% without moving the northbridge voltage up on a p5k pro.
 
Nov 26, 2005
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Memtest HCI is a good test too. Be sure to run it. IMO it's better than Memtest86 v4.0

The ultimate test is playing UT3. If something is unstable, it'll surely crash.
 

Wineohe

Junior Member
Jul 21, 2008
18
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0
I echo dguy6789's comments, just do 3.4mhz. I'm running everything at 400mhz at 1.2v. Any of the utilities I use actually report an even lower voltage. It's rock solid. You shouldn't need 1.328v. I have four memory modules installed and they are very finicky about anything above 800mhz anyway. So memory is set to a 2.0 multiplier. So it's a no brainer overclock.
 

ZipSpeed

Golden Member
Aug 13, 2007
1,302
169
106
Going to chime in that I also ran my Q9550 @ 3.4 GHz at 1.2 V and 1:1 RAM for a year and half with no problems. Southbridge, northbridge and RAM running at the lowest voltages I could select in the BIOS.