P4C800 Deluxe ,faulty voltage ?

Got my new rig about 3-4 days ago :
3.0 C SL6WK , 2X512 PC3200 samsung and a P4C800 deluxe .
After one post at 3.0 .I decided to overclock right out of the box.
3300 ==> OK
3600 ==> Ok
3750 ==> OK
3825 ==> Ok
3900 ==> Ok
4000 ==> Post but , crashed on loading windows .

needless to say I run on 5:4 settings not 1:1
Strange is that I run every damn game ,every bench even memtest at 3825 (got some locks up at 3900 too) but no way it will run prime95 even at 3600 : tried with disabled pat mam etc ...no way .....even tried 3:2 setting ,on my ram ...damn

I put in 1.725 voltage in it but when I m reading it with asusprobe . when on load it goes down to 1.52 !! never more than 1.61 in any case ...is my board faulty ?
Anyone got an idea plz ?
ps:
I have to point out that I got a 350 enermax power supply , and the bios that came with the board : 0.8

While the P4P800 and P4C800 both have massive Vcore load undervolts, that seems more than a little extreme. My Vcore is set at 1.65 in the BIOS and sits at 1.55 under 2xF@H load 24/7.

Try a BIOS update and/or a different BIOS to see if the undervolt gets better (and make sure you set AUTO Vcore in the BIOS before you flash).

first you should consider flashing the 1015 bios. this may help. your power-supply could be a little more beefy, but it shouldnt be a problem. i have the same board, i used my computer with 1.675 vcore in bios for a month, running a 2.4 @ 3.3. i did this to burn it in. i would always see 1.58-1.61 in windows while under load. now i set it to auto, so its stock voltage. in bios i see 1.48-1.5 under load. most settups will see a little bit drop under load, but i think yours is a little extreme. like i said try flashing the bios to the latest one, follow the instructions on the asus site because you need to use an updated afudos. report back after youve flashed the new one, try a different power supply if you can. if that doesnt work, it may be the board.

thx man ...flashed it , still undervolting but at least only 0.1 v
But still I understand why every damn benchmark runs on my pc at 3825 mhz except for prime 95 and it 's not running even at 3600 mhz ...didn t even bothered to look if it works at default speed

Lapindgarenne said:

thx man ...flashed it , still undervolting but at least only 0.1 v

Click to expand...

Good, that's normal for the board. As long as you're aware of it, you should be fine.

Try to use the memory Black Slot...
I've problem with prime95 blend mode, report error without any pattern, @233 maybe I can run it 3 hours, @220 can report errror after about 10 mins...
move my 2x512 ocz el gold 3500 on the black slot, wow stable 24 hours 3 times in a row.

very interesting. ill have to try this next time i restart. i always thought you were support to use the blue slots first, but ill try the black and see if i can get a better OC or maybe be able to pass prime and mem test at 280FSB. right now my limit is 275FSB do to my ram, trying to save up so i can do a volt mod

You are suppossed to use the blue slots first. You're also supposed to use them at 200 MHz, not 280

Try it and see; it can't hurt.

There are also reports of increased memory bandwidth gained from switching slots, without any change in speed. For me, nothing happens.

I'll try this one and report back ...

Jkee, i think you just misunderstood. you see, my highest clock on my processor now is 275 fsb (12 X 275 = 3.3ghz). if i go higher i get errors in mem test and prime. ive had my processor at 3.6ghz with the 3:2 ratio, but that ratio sucks. what i said was 280FSB, not Mhz. so actually, my memory is running 220mhz right now. i want to try them in the black slots and see if i can do 224mhz. if not, im gona stick em back in the blue and do a volt mod and then i can run 300FSB.

I was sort of joking; don't look at specific numbers in this case.

My point was, the blue slots are recommended for use first, but overclockers aren't out to use things the way they were recommended, we're out to use things as fast as we can get them to go.

tested the black slot ...not being able to get rock stability in prime95 while running super pi , memtest 3Dmark cpumark etc ...I don't get any errors that's damn strange : why does my chip fails in prime95 ,I don't get it . Surely he would fail in some other bench too ...but NO !
Also I ran into another problem today increasing the voltage to 1.75 my pc wouldn ' t even boot up (actually once in 5 try) since I flashed the board ...anyway I 'm afraid of frying that one or getting a damn SNDS , so I think I'll put it into a safe range like: ~3700 mhz and let it burn for some time there before I try to push it further .

yeah i tested my black slots too, they didnt yeild anything better.