Overclocking Question

DirkVoodoo

Ok, I bought a machine last year, and AM2 rig, specs as follows:

Athlon 64 3800+ 2.4GHz (12x200) (AM2) with Zalman CNPS9500
Asus M2N-E (BIOS 0802) 200 MHz FSB
Corsair XMS2 PC6400 C4 (4-4-4-12 @2.1V) 2x1GB modules

So, last time i tried overclocking, i came running on to boards in a panic, believing i now had an expensive aluminium footstool sitting in my room. Thanks to you guys, I only needed to reset the CMOS, phew!

Anyway, I've been dipping my toes into the acidic waters of overclocking recently and managed a meagre "just-past-stock-clock" of 210 MHz with no problems. Not exactly one small step for mankind, but I was proud.

However, as soon as I went to 220MHz, Windows refused to boot.

So, I've been looking around and this M2N-E board is a real groin-grabbingly poor board. Some BIOS revisions have enabled people to get up to 285MHz FSB, but I'm wondering what I am doing wrong?

I can find no reference for FSB:RAM dividers in the BIOS and the board is limited to 1.95 VDIMM. Google has only found an anandtech forum where people complain about how bad the board is.

So, I'm falling on the mercy of the boards OC community to help, does anyone have this board? Does anyone have a friend or relative, or maybe pet, with this board? I just want a modest overclock, but I don't know what im doing wrong. I have a sneaking suspicion that it may be linked to the VDIMM, should i loosed up the timings for the 1.95V? Shoud my vcore be on auto?

Cheers guys!

Anti

Right where do i start...


Fisrt of all, im not supprised the machine refused to boot with a higher fsb, For one simple reason. You have not increased the voltages for the other components. such as cpu and chipset. And you have not loosened the timings of the ram. Even though at a moderate overclock you shouldnt have too.


I could explain it all too you, but i think its easier if i give you this link:
http://www.planetamd64.com/index.php?showtopic=12066&hl=overclocking+guide

Its a nice guide that will surely help you.

DirkVoodoo

Thanks Anti, I'll try it out when I get home.

Just one last question: Is the VDIMM limit of 1.95V going to cripple my overclocking ability with this DDR2-800 RAM?

L31mr0d

ok baby steps here...

first get a digital camera and take pictures everytime you make a change in the BIOS and post them here, it will save both you and us a lot of time as we wont have to keep asking questions like "did you change this bios setting?" "what about that setting?"

Second, lower your HTT multiplier to 3x (it should be named HTT muli. or something and have options for values from 1 to 5) This should never exceed 1000Mhz and is a multiplier of your FSB. (i.e. if your fsb is at 220Mhz, then your HTT is at 220x5 = 1100Mhz which is bad, it shouldn't go past 1000Mhz)

Third, change your RAM divider from 1:1 (i.e. DDR400) to 1:2 (i.e. DDR200)

Do this and post some pics then try to boot

DirkVoodoo

Ok,

Anti: thanks for the guide, downloaded it, printed it and read it over the weekend, did testing on friday and saturday.

L31mr0d: Thanks for the help, my camera doesn't do screens very well, will wait until i can get my hands on a better camera.

Anyway, long boring story short: followed the guide, max HTT got to 300 MHz before I said "that's more than enough" ran Prime95 for an hour at each 20 MHz increment, no problems. (VDIMM = 1.95V, VCORE=1.44V, HT=x3)

Next, moved on to the CPU testing phase, this time incrementing HTT by 5 MHz each time. At stock, I could keep the system stable at 1.400 VCORE, but even at 210 MHz HTT the system would not crash while running Prime95 for more than 20 mins (Upped VCORE to 1.45V in the BIOS)

Im gonna try again, with a higher VCORE. One question though, whatever i set the VCORE to in the BIOS, Asus Probe 2 reports it as significantly higher. Is this an inherent measurement offset error in Probe or is my board unable to supply steady voltages? e.g. 1.45V in BIOS shows 1.56V in Asus Probe.

I'll keep you updated, next time with pictures.

Anti

That is called vdroop my friend

L31mr0d

that will be your mobo my friend. I've had HORRIBLY problems with vdroop and faulty temp sensors on every ASUS mobo i've use. But over 0.2v seems a bit odd. Maybe try another program like CPUz or speedfan to read your voltage levels, there might be an offset built into asus probe.

DirkVoodoo

vdroop, cool.

Yeah Asus Probe overstates the vcore while cpu-z and speedfan both give readings under the BIOS rating. I wasn't sure which, if any, to trust.

Cheers guys, this is a very new and interesting topic to me.

P.S. Ive attached a picture, its blurry as my camera is not able for it. I think ASUS probe is showing 1.48V and CPU-Z is showing ~1.3V.

EDIT: Sharpened the image, its 1.312V on CPU-Z and 1.49V on Probe. BIOS was set to 1.400V

Anti

Trust cpu-z. ignore the asus prope bull****.

awhir

use prtscrn man.

press prtnscrn ,then go to paint and paste it in:D

DirkVoodoo

Duh! Its always the most simple answer that proves most effective, thanks awhir!

Ok, so 2 pics enclosed. COMP.jpg is the BIOS vcore set to 1.500V and COMP1.jpg is vcore set to 1.525V.

For a HTT of of 220 1.5V, prime95 halted after a minute.

At 1.525V I have yet to test, but Prime95 ran for a few minutes.

I think this board is just a crap clocker, looking forward to Core2Duo price chops!