3.3v rail question.

[spaceman]

OK, I only recently started playing around with trying to put more voltage to my 3.3v line, to OC my RAM higher (BH-5). It seems like any more than 3.54v corrupts the AGP. Doesn't the 3.3v also feed the AGP slot, and is there a work around for this? Using the DFI 250 Gb. Thanx for any input, this is drivin' me nuts.

[saaya]

hmmm weird... what makes you think the agp voltage is too high? can you meassure it?

afaik the dfi board uses the 5v rail to creat vdimm and NOT the 3.3v rail ;)

i wouldnt increase the 3.3v rail as i heard some a64s died from too high 3.3v rails!
bawoman said he killed several chips with a too high 3.3v rail! i think around 3.6v or 3.7v! so back down that 3.3v rail, it wont help you to get a higher and more stable vdimm anyways :D

[WeStSiDePLaYa]

hmmm weird... what makes you think the agp voltage is too high? can you meassure it?

afaik the dfi board uses the 5v rail to creat vdimm and NOT the 3.3v rail ;)

i wouldnt increase the 3.3v rail as i heard some a64s died from too high 3.3v rails!
bawoman said he killed several chips with a too high 3.3v rail! i think around 3.6v or 3.7v! so back down that 3.3v rail, it wont help you to get a higher and more stable vdimm anyways :D


nope dfi UT uses 3.3v rail.

get the modded bios from dfi-street and it will let you to use vdimm that is .1v less than your 3.3v rail. so if you set 3.3v rail to 3.5 you will have 3.4vdimm max. ;)

[craig588]

Usually its around .3V below the 3.3 rail. When I had my 3.3 rail at 3.5V I could only get 3.2V max. At 3.7V I could only get 3.4V.

[WeStSiDePLaYa]

Usually its around .3V below the 3.3 rail. When I had my 3.3 rail at 3.5V I could only get 3.2V max. At 3.7V I could only get 3.4V.


was your line drooping?

straight from jess and oskar it should be .1v. and thats what others have said. maybe your board is funky? are you reading from the dimm or within windows?

[craig588]

I was using a DMM, and my lines are right on. (In fact, under load they acctually increase for some reason)

[spaceman]

I figured it out! :banana: :D First off, I'm 95% sure that craig588's right, working vdimm is .3v below what a DMM or the BIOS shows. ;) Now when my AGP started goofing up, I thought the higher 3.3v line was overvolting the AGP, so I turned it down to 1.5v. It finally occurred to me, that maybe it was the other way around, and the vdimm was sucking juice AWAY from the AGP. So I tried it with 3.4 vdimm, and 1.7vagp, and it works! :D I've got 256.5 solid on the RAM, and was mostly stable, but not solid, @ 260. :cool: 256.5MHz. gives me 4012/4012 bandwidth in SANDRA, and Super Pi gave me 1M=33s, and 8M=6m 50s. I'm gonna run it there awhile, with F@H running, to see if some burn-in time at that voltage helps. I'm pretty sure it will. Later on, I should be able to feed it 3.6vdimm. :cool: