Reasonable NB(mch) voltage and temp for overclocking?

[devilchrist]

seems i'm getting the in-place large fft stability by raising the NB(mch) voltage.

I'm at 1.5v NB volt and my MSI p35 platinum board stays at a cool 31c.

how far can i push this? I don't want to go in to exteme overclocking but i'd like to get close to 3.8ghz. on E6750.

current setttings and parts

MSI p35 platinum
E6750 450x8 3.6ghz at 1.4875v, 4x 120mm fans push pull
Corsair 2gb Dominator 8500C5D 120mm fan blowing on it
ram 1:1 setting 900mhz
5-5-5-15
1.5v NB volt

 

[Idontcare]

Originally posted by: devilchrist
I don't want to go in to exteme overclocking but i'd like to get close to 3.8ghz. on E6750.

current setttings and parts

MSI p35 platinum
E6750 450x8 3.6ghz at 1.4875v, 4x 120mm fans push pull
Corsair 2gb Dominator 8500C5D 120mm fan blowing on it
ram 1:1 setting 900mhz
5-5-5-15
1.5v NB volt

Dude that's pretty extreme already. Seems like you are pushing a lot of air, a lot of volts, and a lot of GHz already. Congrats!

Regarding P35 - ask aigo or Yoxxy but I believe the P35 doesn't have a temp sensor in the chipset, so you are really flying blind as to how hot your 1.5V is pushing your NB.

The P35 on my DS3L does not have a temp sensor, this I know, it is pretty blind to NB temps.

As to whether 1.5V is high or not...it seems crazy high to me, I stopped pushing mine at 1.35V but then again I overclock quads not dual-core so you are in a whole different ballgame there.

 

[VirtualLarry]

1.5 NB volts seems a tad high to me too. What is the default voltage? 1.25?

 

[Idontcare]

Originally posted by: VirtualLarry
1.5 NB volts seems a tad high to me too. What is the default voltage? 1.25?

I got 1.20V for P35 on DS3L. But as we have discussed before not all P35 on all mobo's appear to be the same so I am relunctant to pass these numbers off as "good across all mobos". Is it 1.25V on yours? I wonder if this is like VID where Intel might allow mobo makers to have a range of allowed "stock" voltages for the P35 on their boards.

 

[devilchrist]

In my bios i have it named as system. I would have assumed that it was NB?. I guess i'd have to check with MSI on that one to make sure.

I have 1 fan at the front of the case pushing air to the CM hyper212 fan, then i have pulling fan on the back of the CM212 that's ducted to the back of the case. Almost a straight line of 4 120mm fans.

1.25 is the default on this board.

When I push the FSB to 450 it auto pushes the NB to 1.45v. so i assumed it be ok to push it to 1.5 without too much fuss.

Regarding P35 - ask aigo or Yoxxy but I believe the P35 doesn't have a temp sensor in the chipset, so you are really flying blind as to how hot your 1.5V is pushing your NB.

As for temp. I touched the NB heatsink and it seemed colder that cpu heatsink when running the torture test. so i'd assume that it be within reasonable limit.

 

[Idontcare]

Definitely sounds reasonable to me too. I haven't heard of anyone killing their P35 from overvoltage, it seems to be more of a thermal issue, so if the temps at 1.5V seem manageable then you likely can push onwards and upwards.

 

[EarthwormJim]

I have my DFI LP LT P35's nb at 1.6 volts. It has a thermal sensor on it, never gets above 42 C, but I do have it water cooled.

As long as you have a fan blowing on the heatsinks, 1.65volts would be the upper limit for 24/7 operation. Honestly for any overclocking, I'd have a fan blowing on the heatsinks. Doesn't have to be a powerful fun. Say an 80mm fan running at 5v or 7v.

I have read of nb's failing, but those were at 175volts or higher.

 

[The-Noid]

1.55 is max according to the whitepaper. My chip started to degrade @ 1.65v. As for temp, system is usually just the motherboard. My theory on nb is that if they get too hot prime will fail.