I/O voltages 3.7V, 3.8V, 3.9V safe? How high is yours?

[MCS]

It seems I need to raise my I/O voltage to at least 3.7/3.8 maybe more to get my KT7A stable at 150Mhz FSB. I am not worried about the actual chipset running at this voltage but I am worried about frying my memory/AGP card which also use this voltage...

How high are people running theres?
Has anybody ever caused damage because of high I/O?
Would Abit even allow you to go to 3.9V unless they knew it was safe?

Thanks

 

[AndyHui]

Those IO voltages are way too high. Considering that the default IO voltage is 3.3 volts and some manufacturers allow a maximum of 3.4 volts, I think you would kill everything with voltages like 3.8 or 3.9 volts.

AGP, PCI, DIMMs and chipset all use IO Voltage.

 

[Bartman39]

I agree... 100% ever see dead memory sticks??? High IO is the #1 killer...

 

[MCS]

^^^^^^

 

[medic]

I would agree with Andy...I have seen this a few times where a client raised the I/O and fried his ram.
The highest I would ever go would be a 3.4 or 3.45 and even then I prefer to leave the I/O stock.

 

[The Reaper]

I thought 3.4 was default for AMD? That's what my KT7A runs on 150FSB CL2. I've gone up to 155FSB with no problems on a week 49 northbridge. Maybe your ram just can't take the 150FSB.

 

[medic]

The Reaper

Correct, the default for many AMD boards is 3.4V, my OLD workhorse K7M has a default of 3.4V. but has run for over a year at 3.31V. (500@7.5)

Big jump though up to 3.8-9V...

 

[MCS]

I haven't actually gone above 3.7v as yet.

I have tested my RAM to be stable up to 155Mhz (its Crucial CAS 2). I used a lower FSB to test the AGP and PCI at the equivilent speeds, so no problem there.

Its risky of Abit to allow you to set the I/O so high then?

 

[Big Lar]

I agree with Andy also, and Abit would just refuse the Rma more than likely if the board blew out, which IMHO, that is what would happen, Some boards, such as the Asus P3b-f as I am running, default out at 3.5v, and I personally have run as high as 3.6v for the I/O, but 3.5 is plenty high for even the fastest of ram timings, and for the biggest Voltage Hogging vid cards. Just my $.02

 

[Eug]

For some of their boards (ie. my P2B), the much revered Asus sets the default voltage at 3.5. VIO can be set at 3.7 for testing/overclocking.

I've had mine as high as 3.7 for testing to get some function out of my old cheap@ss memory overclocked. However, I've come to the conclusion that if my system took 3.7 to work then it's too close to the edge for comfort. Personally, I would back off from 150 MHz.

How about 140 MHz at 3.5 VIO?

 

[MCS]

Yes I can run 140-145 FSB using 3.5/3.6V or so.

I can run 133Mhz FSB using just 3.2V, but at this setting the PC won't even POST at 150Mhz FSB.

 

[rickn]

I have 3.6v on my p3v4x. Default is 3.5v

 

[MCS]

Thanks all for your advice/opinions.

I think I will stick to 3.5/3.6 as my limit.