this has been buggin me for months, and now i'm finally blowing a gasket on this one. first my setup

P4C800-E deluxe
2.6C o/c 3.25 vcore @ 1.55
OCZ PC-3700 fsb@250 1:1. latency @ 2.5-3-3-6
Swiftech MXC4000 heatsink w/ ceramique applied and memorex silent fan on top
Geforce 4 4400 o/c 300/630
Antec True power 480 w/ blue led
Creative Audigy 2
23" cinema display hd

my case has 5 fans total, 2 intakes on the bottom, 2 on the rear, and one on the top. they aint that good of fans cuz i can just by feeling the flow of air being too little. anyways here's the problem, my system idles @ 27-28 deg C, and loads at around 42-28 deg. C, depending on what i'm doing with it. now what pisses me off is when it gets to around 48 deg. C my computer always locks up, and i know damn well that it shouldn't, cuz i know everyone else on this damn planet has theirs up to 60 deg. C and they're still fine. whats even more mind boggling is the fact that the temp. sensors from the bios, probe, motherboard monitor are all reading the same temps within 1-3 deg. of each other. so obviously something is wrong here. the only way i can counter this is keeping my case open on the left side to let the air vent out. but its not the fact that my computer locks up cuz of the hot air inside, but because its locking up @ 48 deg. C. but as soon as i'm running heavy cpu app's and the temp starts to approach 41 deg C, i'm forced to open the side case, so it don't approach the 47-48C mark. As a last resort i've set all my system settings to their default value and ran every app and game to load the cpu and i still got the same result. when i tried running prime 95 and it failed after the first 5 seconds, yet memtest ran flawlessly, so i can pretty much eliminate the memory problem. i'm wondering if if it could be my northbridge or vid card overheating on me, but i doubt the vid card, cuz it locks up at 48C even when im not using it for gaming. anyone please give me a logical explanation as to wtf is going on here...........

PS: i've already tried the voltage where i've put it up to 1.65 and also put the clock rating back to normal and still the same results. any other suggestions...

It could be any number of things. Asus is known to read temperatures a little low. When overclocking, it could be just one BIOS setting that's throwing it off, like MAM or PAT.

I'm sure you've probably noticed the Vcore voltage droop on your board also. If you set it to 1.55, when idle in Windows it's overvolted to almost 1.6, then you give it a heavy load, it droops, sometimes down to 1.5 or lower.

If you have 1024MB of RAM and not the most recent version of Prime 95, then you're going to fail. There was a bug in P95 for systems with 1024MB RAM. Latest version is from February.

Even though it passes memtest, try loosening your RAM timings or going with a 4:5 FSB:RAM ratio.

Dumb question, have you locked the AGP bus?

If you're overclocking that much, attempting to run a quiet rig is not such a good idea. Sounds like you're running everything at the edge without superior cooling.

Lastly, it could be driver conflicts. Prime95 can flake out with bad drivers.

malcore,
i forgot to mention that with the ocz sticks i'm using, they apparently dont like settings beyond a 1:1 ratio. its kinda weird but if i were to put the fsb at 200 with 4:5 it wont boot, so anything less than 1:1 it won't work, and naturally i found this out by doing some research on goodle. in addition, i found out on another forum, prime 95 is not a good candidate with my board, so i can forget that program for now. AGP bus is locked at 66/33 otherwise i wouldn't of been able to o/c this sucka. the only logical explanation is that my cpu came out bad since i bought it oem, and i've also found out that retail cpu's performed better than oem's most of the time, but unless i had a spare 2.6C chip running around, there's no way i can compare it for now.

I'm sure you've probably noticed the Vcore voltage droop on your board also. If you set it to 1.55, when idle in Windows it's overvolted to almost 1.6, then you give it a heavy load, it droops, sometimes down to 1.5 or lower.

that is a default mechanism that ASUS put on their for default purposes, who the hell knows why, but it's said that it won't effect your overall system. i'll be sure to take that with a grain of salt.

keep up the feedback fellas.......

Most people using the same OCZ sticks as you and setting the FSB to 240 or higher are running it 5:4. Meaning, the memory is set in the BIOS to 333MHz. At 250 FSB the RAM would then run at DDR400. At 250 and 1:1 the RAM is running at DDR500, and those timings of 2.5-3-3-6 are just way too tight to run stably at 500MHz. That RAM is rated at 2.5-4-4-7 at DDR466. Even OCZ's Premium Gold enhanced latency DDR500 is only rated to run at 2.5-4-4-8 at 500MHz.

I don't know what forum you heard it on, but saying Prime 95 is not compatible with a certain motherboard is a serious case of denial.

250 is a pretty steep overclock, without really relaxing the timings and/or getting some serious cooling going. The northbridge chipset is getting pretty hot there.

OEM vs. retail, another urban myth there, much like saying a Malay chip is better than a Costa Rica one. Pure garbage.

Also, a lot of folks hitting the upper 200's have performed a droop mod on their boards with a pot to bring the voltage up and keep it up when under load.

What are your temps at stock speeds, no overclock? If there's a delta of over 15 degrees between idle and load, your cooling is just not up to snuff.

here's where i got the prime 95 information, unfortuately it's buried somewhere in that thread, and i forgot the exact location...
http://www.abxzone.com/forums/showthread.php?threadid=49225&perpage=15&highlight=agp%20aperture%20size&pagenumber=1

and the oem vs retail myth has more truth to it than it seems, because i read it on an article 6 months back on xbitlabs once, apparently it was from an inside source which was later confirmed, but the story never picked up steam i guess, and was buried in time.

at stock they're actually pretty much the same, only 2-3 degree difference at times, and i am in total agreement about my cooling system just sux, the fans inside my case blow little or no air at all, and thats gonna need a major overhaul. sooner or later i'm gonna take the water plunge, but not for a few more months, the main point was trying to establish the cause of my low temp lock-up.

and the oem vs retail myth has more truth to it than it seems

You'll have to back that up with something pretty reliable before I'll believe it. The only difference I've ever been able to find out between OEM and retail is the box with purty pictures and a warranty. Builders like your local computer shop don't need the box, and they usually handle warranty themselves. I always have...Otherwise it's the same CPU, just different packaging...and I've built a bunch of systems with OEM chips. Probably close to 100. Only had one CPU/heatsink come back, and it had a broken fan blade so I was pretty sure it was user damaged...

Back to the problem though...I don't think it's so much temperature and cooling as it is overclocking itself. When you overclock a machine you invite trouble, and system instability is the most common problem, once the heat issues have been dealt with. And here the cooling is still obviously an issue although the temps aren't getting too high. If it's unstable you're trying to squeeze too much out of it, drop it back some and loosen up the memory settings.

I don't recommend overclocking at all and for the most part don't support it, I figure if you want to run it way past its rated speed, you're asking for trouble, and it's not worth scrapping motherboard, RAM, video card and CPU when a faster CPU would cost about 1/4 as much as all that combined or less, depending on what you buy and where you buy it. Not to mention voiding the warranty and banging your head against the wall trying to figure out why it won't run right. It's rated at a certain speed for a REASON...

pete,

you need to be live more dangerously buddy :)...

Really? Who's the one with computer problems??? :rolleyes: