Power Loss when running Prime95

[The Green Bean]

My system is:

2500+@1985MHZ@1.75V
PC2700 K VRAM @ 360DDR 1:1
120 gig 7200.7
ti 4800SE
300 Watt PSU with low ratings

Whenever I run Prime 95, After 4-5 mins, the power just goes down. My monitor on the PSU works, but I cant even turn my rig back on. Then, I have to unplug and replug the Power Cable?

My guess:
1. Bad PSU
2. RAM!
3. Processor chip?

Most prolly the PSU. Will a 300W PSU with a much better rating be suitable or should I get a 400W PSU? No use getting something I dont need cuz PSU prices are pretty high especially the high end ones this part of the world.


Will be upgrading to PC3200 RAM but for now this looks fine.

Also when I try to run Prime 95 after I crank up the FSB to 200, (ram at 333) I get calculation errors immidieately. Why?

Also wanted to ask the MAX speed I can run a 512 stick of Kingston Value ram Pc2700? currently at 360.

thnx

hatim

 

[Alkaline5]

Sounds like bad RAM to me. Have you tried memtest86?

 

[biostud]

PSU

 

[The Green Bean]

rams fine...Ran memtest w/out a hitch for an hr and a half.

 

[Boogak]

Definitely your PSU, I've had the same problem with wimpy mATX power supplies where it would shut down when running Prime95. Upgrading to beefier power supplies fixes the problem. I'd get a quality 300w - 350w power supply, no need for 400w unless you want to be futureproof.

 

[mechBgon]

Another reason for complete shutdown is high CPU temperature. Try opening your case and blowing air straight into the side of the computer with a house fan, if you want to test whether cooling is part of the cure. But I agree that a new good-quality power supply may be a good idea too

Besides high case temperatures or an inadequate heatsink/fan unit, an incorrectly-installed heatsink can also cause the CPU to overheat. It does not seem very likely that your system would run at that OC with an improperly-installed heatsink, but just in case... heatsink photo guide.

 

[The Green Bean]

I noticed that CPU shuts down when 52C on Prime 95. However, I played CS for 45 mins and CPU temps were 54-55 and nothing ever happened. And Ive heard that AMD can go ~60-65C easy.

thnx for the link

 

[Mark R]

As said, this may be a thermal shutdown on the motherboard - usually a result of the CPU getting too hot (or the thermal shutdown option in the BIOS being set too low).

The easiest way to check this, is to open the case on the computer, boot up, and run something that normally works fine. Using a domestic hair-dryer warm up parts of the system one-by-one (e.g. motherboard chipset, CPU, PSU) to see if you can reproduce the problem. If you identify an overheating part, make the appropriate changes to the cooling.

 

[The Green Bean]

The PC shuts down at about 52C as I said. Running stock setting, it ran at 63/4 b4.

 

[JohnPaul]

No sense in getting a 300 or 350 watt ps when a 400+ is not much more expensive, and can be used in your next build most likely. But, yea, it definitely sounds as if your power supply cannot handle the extra load of prime 95

 

[The Green Bean]

please do read the posts b4 replying. The 400 Watt is 3 times the 300 one. Im frpm karachi Pakistan btw. 300 W for $10, 400W $30

 

[The Green Bean]

1.ok...I got a new PSU 350W with a better rating. Also bought new RAM. Kingston Value Pc3200 (I noe it sux for ICing...but its the best I could fin here).

2.Im underclocking my Ram to OC my CPU. 181MHZ. Even last time this weird problem arrised, I was either increasing or decreasing the RAM speed. Surprisingly, Memtest 86 runs fine.

3.I have a stock heatsink, temps are 50 under full load at stock. When I oc raise my vocore, load is 56-7.

4.Whenever I try ro boot with 200MHZ core, Windows hands up on the welcome screen. No mouse movement even. Tried different voltages from 1.65-1.8. Same prob. So I cant test if there is a problem with the ram speed being increased ot decreasd.

5. My Ti4800 heatsink seems extraorniraly hot (much more than the AMD HSF.) it covers the whole card but is really hot. Dont think that to be a problem though cuz games work problem free. I have a 120 mm case fan blowing on to the card and processor effectively
Plz help

hatim

 

[The Green Bean]

bump

 

[mechBgon]

Is your power supply equipped with a 115-volt/230-volt selector switch on the rear? Is that set to the correct input voltage?

I did have a Pentium3 450 that had a partial core failure. It would run fine under any load until its SSE capabilities were used, and then it would lock up the computer immediately. Very strange. And it was in a dual-processor system, so that didn't make me very happy :frown:

hatim, what kind of thermal-interface material do you use between the CPU core and the heatsink? If it is the stock AMD thermal patch, remember that they are good for only one use, and then they must be scraped off, and replaced with high-quality thermal grease. If you have removed your heatsink in the past, but have not used thermal grease, then try that next Good luck!

 

[The Green Bean]

we only have 230Vs here

Im using AS5...

Its pretty wierd cuz Prime 95 runs 5 hrs straight on stock. If I increse my FSB by 20...restart. I have a feeling it has something to do with the ram not running at normal speed.

 

[Sid59]

could always try and chipset bump, memory volt bump/.

 

[The Green Bean]

trid that also...

Ok when the I oc so that the BIOS detect the proc as 3200+, windows doesnt boot at all. Everything else is normal ?

Maybe its just a bad mobo or proc

 

[Sid59]

what mobo? - make sure you choose USER DEFINED settings and not choose an option for it to 'auto-detect'

 

[The Green Bean]

Ok i updateted drivers and Bios...Yet to run P95. But I ran 3D mark 12227 marks from ~11000. And temps were 42 at the end of the tests on speed fan....

Can this be possible, some problem with Prime95?

 

[The Green Bean]

Same prob....now running SisSandra arithmetic continous test.

 

[The Green Bean]

sissindra even has the same reslut!
The problem is definately in my setup. What could be wrong. Happens only when I oveclock. RAM speeds??

 

[SmokeRngs]

What motherboard do you have?

If it is not an nForce2 chipset board, then when you change the FSB your PCI and AGP frequencies also change and run out of spec. You could easily have a card that doesn't like the higher PCI/AGP specs and that is why your system goes down.

 

[The Green Bean]

its an Nforce2....

I might just try and do this in some time if dis doesnt work. http://www.ocworkbench.com/2004/guides/unlockwk43update/ocw_unlocking_xp39+.html

 

[The Green Bean]

might be a heat problem. So ill just give up on Ocing for now. Until I actually need some more power. But that wont be before I get a new Proc