PCA Forums

So I've had my current PC for some time now. Specs are as follows:

Athlon 64 X2 4000+ Brisbane, 2.1GHz Stock, OC'ed to 2.7GHz
aBIT AN52 Motherboard, nForce 520 Chipset
2GB (2x1GB) G-Skill DDR2 800 RAM
Sapphire Radeon X1900GT
Antec NeoPowerHE 550W PSU

The computer is rock solid stable when it actually gets to windows. Prime95 for 5 hours straight on both cores, and no issues whatsoever.

The problem I have is when the computer actually boots. I don't normally leave my computer on 24/7, can't afford the electric bill. When the computer starts cold, it won't POST right away. You have to press the power button, then the reset button for the PC to POST. Granted, this only happens when I have the computer overclocked. If everything is set to stock settings, then it POSTs as soon as you hit the power button.

I know an obvious answer is 'don't overclock', but I'm more curious as to why it does this? I really have no spare parts to test individual components, but I'm wondering if anyone else has an opinion as to why it does this? I'm kind of leaning towards the power supply, but I figure it's plenty beefy enough with triple 12V rails... it could also be the motherboard, since it is a lower-end model (1 PCI-E 16X slot, yadda yadda), but it is a hell of an OC'er.

All input welcome... also perhaps ideas how to rectify the problem... other than not OC'ing, of course. This thing hauls butt

Thanks
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Edit: Posting some more detailed OC Specs

Core Speed - 2732MHz

CPU Multiplier - 10.5x (Locked)
FSB - 260
HT Multiplier - 4x (1040MHz, 1000MHz Stock)
DRAM Frequency - 390.3MHz (DDR2 667 downclock)
Timings - 5-5-5-15 (Stock)

CPU Core Voltage - 1.35V (1.25V Stock)
Memory Voltage - 2.1V
Hyper-Transport Voltage - 1.2V
Northbridge Voltage - 1.2V

I would try another power supply. If that doesn't fix it, make sure the voltages are correct for your clock speeds. If nothing else, you're going to have to turn the clock speeds down or get another board. Abit boards are nice though. I had one for my Prescott P4 478 and I ended up selling it on e-bay for almost 90% of what I bought it new.

I've gone over the OC settings with a fine-toothed comb, and this is about the best I could get. I upped the voltages on pretty much everything except RAM, since it's technically staying underclocked a bit. I'm thinking if the multiplier of the processor was unlocked, I wouldn't have this problem, since it only seems to rear it's ugly head when I jack up the FSB.

If I ever get a chance to get another powerful PSU, I'll drop it in for a test, but I don't have anything in the house near powerful enough to POST the computer.

Another question would be... is there a chance that continuing this could kill the computer? I have no real problem pressing the reset button after power, except for a small annoyance factor, but another concern would be can this cause any major damage to the components?

sounds like ur mobo just has an issue with overclocking. Is cold boot really cold or is the PSU always left on. If ur like my dad and flip the power strip off could have a CMOS battery with low voltage as they die faster when the psu isnt constantly sucking juice and the reset is re triggering with OC values that doesnt need to happen when the defualt values are used. What extra hardware do you have, try using it with nothing but mobo, cpu, 1 mem stick(at a time), onboard vid if available, and 1HDD. I some times forget to dumb down the problem and yanking out extra HDD and ram solves the issue real quick

And for the killing the computer part shit happens as they say, If you happen to get a component that has better tolerances it could just as easily been sold as a higher end part like the limited editon CPU's(hand picked I think they refer the practice as). It comes down to tolerances and you never know if. Basically if its gonna break its gonna break OCing just magnifies the problem


One last thing bumping Volts should be a last resort when higher OC is unstable and extra juice fixes windows issues

First off I wouldn't just bump the voltages indiscriminately. I would also avoid overclocking the system for now and just set the default voltages. If the system's not stable (and if it doesn't POST it's not stable, then don't overclock it. If the problem persists with a normal clock THEN you know there's something else wrong. You can't diagnose anything if you're overclocking and over voltaging.

Assuming the problem persists at normal clock and voltages, my suspicion would be a weak/unstable PSU. I would also closely examine the motherboard for swollen or leaking capacitors. Difficulty POSTing but rock solid once it does post is a classic symptom of either one.

If it's the PSU it's impossible to say if it's doing long term damage. I did have a bad PSU (it had bad caps when I opened it up) that worked fine except that every time I turned off the PC (which was rare since the system was on 24/7) it would voltage spike the HDD and eventually kill it. Went through 3 hard drive RMAs until I figured it out.

Another possibility is that your RAMs just aren't matched close enough for Dual Channel Memory mode. Try configuring the memory for single channel (instead of one stick in each bank, you put them both in the same bank). Moreover, you should not be using dual channel mode at all if you intend to overclock. It's just not stable.

Hope this helps...

Well, hard drives aren't the best thing you want to be resetting the power on while in the middle of operation. First thing, take off all overclock and return to defaults. If the problem no longer occurs, now you know the fault.

Sometimes a system will refuse to POST because of an overclock and go to defaults on the reset, in which you may not actually be overclocking after all. Make certain whether or not is actually overclocked after the reset.

Thank you for all of the helpful replies. I am here to post a bit of an update, as well as clarify some of the things I said in my original post.

I suppose I did not make it clear enough in my original post that the problem does not persist when the BIOS is set back to default settings, so I know that the overclocking is causing the problem. I was more posting this thread to receive input more on the 'Why does it do this?' part, more than the 'What causes it?' part. I suppose there could be a number of problems, ranging from the motherboard itself to a weak power supply, to a crappy northbridge.

When I purchased this system, I did many hours of research on each individual part that I selected. The processor was one of the more important decisions, as I bought the system mostly as a budget system, but I also wanted to build a good overclocker system, too. And I believe I have succeeded in that goal, to an extent.

I selected the processor because, being based on the new (at the time) Brisbane core, it's a 65nm core, which means lower heat output, and more overclocking headroom. I bumped the voltage of the processor up from 1.25v to 1.35v because the voltage thresh-hold between these cores ranks all the way up to 1.4v. I was just lucky enough to get one of the first lower voltage Brisbane processors, but it is just as capable of taking the 1.35v as it is the 1.25.

Taking a suggestion from FP, I switched the memory over to single channel mode with no luck. I purchased these two sticks of RAM as a matched pair, and CPU-Z shows the serial numbers of both sticks within one digit of each other.

Interestingly enough, I ended up answering my own question... when I purchased the system, I chose the Abit An52 motherboard because of it's low price point, but also it's superior overclocking ability. But more research into the subject shows that the particular board I purchased just happened to be part of a batch that shipped with a flaky northbridge, so I assume this is my problem.

So I'll consider this problem as 'solved'. Now that I know what has caused it, I really am not all that worried, because I eventually plan to replace the motherboard and video card to something a bit more beefy.

Thanks for all of your replies, I appreciate you taking the time to listen.

Cheers, Josh

if you are gonna overclock...DFI

Or Asus...