Limits of CPU Voltage

[eon_designs]

Question - have I reached the limits of my current CPU Voltage?

 

Running Q6600 (G0 Version) with 4 x Corsair Dominator PC2 8500 C5 Ram (2 matched sets of 2GB) Air cooled with 120 Ultra Extream. ASUS P5K Premium Wifi Motherboard

 

My current settings run very well with over 10 hours of all 4 cores in Prime:

 

FSB 361, CPU volts 1.3250 Ram at 4:5 ratio (905MHz) Load temps max at about 56-57 degs C

 

Problem is if I try and push the FSB to 367 so running at 3.3GHz. When I run Prime on all 4 cores after about half an hour the system reboots.

 

Is this because the volts are too low? Ram running too high? (Should I lower to 1:1 ratio?) Need to change Northbridge or FSB terminal volts? (Both currently set at lowest setting)

 

I don't really want to increase the CPU volts as maxed it reaches 62-63 degs C which is a little too hot. But just wanted to know what others think?

 

Thanks. eon

Edited February 12, 2008 by eon_designs

[kingdingeling]

You can still increase the CPU volts a wee bit, my Q6600 needed 1.424V's to run 3.5GHz stable, but it never went past 65

[eon_designs]

Thanks for the reply

 

Looks like your Quad Core is running a little cooler than mine. I would not dare push my volts to 1.4

 

Is 65 Degs sort of the max limit - or is it just down to personal prefs. at 1.3350v it get to 63

[kingdingeling]

Essentially you want to keep your CPU below 70

[eon_designs]

Will have to check the VID tonight.

 

I know it will be around 1.3 - but cannot be sure - so will post a reply later

[eon_designs]

Just had a look at the VID in CoreTemp

 

It is 1.3000v

 

Reading a bit more on other forums - some suggest that when using 4 sticks of Ram it is better to up the Northbridge volts to 1.4 - so going to give that a try and also lower the Ram to 1:1 ratio so that it is purely the CPU that is being overclocked at present.

 

Thanks. Any suggestions please keep them coming.

[cchalogamer]

Reading a bit more on other forums - some suggest that when using 4 sticks of Ram it is better to up the Northbridge volts to 1.4 - so going to give that a try and also lower the Ram to 1:1 ratio so that it is purely the CPU that is being overclocked at present.

VERY true, in fact keeping ram speed below DDR2-800 will help a lot as well when dealing with 4 sticks, loose timings also help out greatly. Though it's all a delicate balance of what you can get before suddenly it doesn't POST

 

Just make sure your keeping the NB cool as well, they get hot with volts or with extra ram to take care of in the first place, combine the two and it just gets worse.

[eon_designs]

Well my first little test did not work - obviously I had reached the limt for that voltage.

 

However, upped the voltage one notch to 1.3375 and increased the Northbridge to 1.4 and ran Prime with 367 x 9 and Ram at 920 (4:5 ratio) and it works perfectly. At max load the temp reaches 61 degs C.

 

I also changed a couple of other settings which were at their lowest voltage back to auto (don't know if that made any difference) CPU PLL to Auto instead of 1.5 and FSB Termination to Auto instead of 1.2

 

So far all working well

 

A little concerned about the 61 degrees - I would have preferred to keep it below 60 - but you and others say below 65 is ok

 

This also possibly gives me a little bit more room to overclock - I may be able to push the FSB a little higher - but will stay at 3.3GHz for now.

 

Any other suggestions?