[llama311]

i recently built a new computer and i have noticed extremely inconsistent performance, such as playing team fortress 2 at 200 fps one day then either several hours later or the next day trying to play it and getting 10 frames per second. one day when it was particularly slow, i ran 3dmark to try to find out where the problem was, and sm 3.0 scored very low, i think it was around 500 where it normally over 6500.

i am confident my processor and videocard are not having heat issues because i monitor their heat, the processor with real temp and the videocard with ATI's CCC. i'm pretty sure sm 3.0 is videocard related so im pretty sure its not some spyware or windows program thats taking up computing power. the only things i can think it possibly might be would be the motherboard overheating or the psu struggling. but i think a struggling psu is a long shot because i havent had any random reboots. anyone have any ideas what could be causing the problem? or how to test if one of the possible problems i listed could be tested without an extra psu or mobo? i've also taken my computer apart and then back together once, the issue happened before and afterwards, so i doubt its a loose connection.

my computer specs.

i have gigabyte ep35 ds3l, a hd 4870, a 37200 (overclocked to 3.0Ghz), 4 gigs of ddr2 800 ram, 32 bit xp, antec earthwatts 500W psu.

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1)don't overclock. I bet your system will be more stable that way.

2)your power supply isn't sufficient. While it will work fine for most things, once you start putting loads on it, it will start showcasing instability issues. Just as your experiencing now. Your total system power consumption is ~200watts at idle. Under load puts it up at your max that the psu can handle. Variations can be caused by the quality of power (supplied to residence) and effeciency of the psu.

[starjax]

1)don't overclock. I bet your system will be more stable that way.

2)your power supply isn't sufficient. While it will work fine for most things, once you start putting loads on it, it will start showcasing instability issues. Just as your experiencing now. Your total system power consumption is ~200watts at idle. Under load puts it up at your max that the psu can handle. Variations can be caused by the quality of power (supplied to residence) and effeciency of the psu.

[llama311]

thanks for the reply. acouple comments though, i'm not trying to be difficult, but just want to be as confident in the problem as possible before spending a significant amount of money repairing the problem. first of all, you know that the psu in question is a high quality psu with over 80% efficiency? also, while i occasionally get slow frames per second, i have never had a random reboot, which is typical of the psu struggling. wouldnt a struggling psu crash the computer and not just cripple the performance of the videocard? also, when i do 3dmark06, the cpu and videocard tests are separate, so there wouldnt be as great a load on the powersupply, yet gpu performance is still well below what it should be. also, at one point, i had my cpu overclocked to 3.16Ghz, and i underclocked it because the psu seemed like the obvious choice, and i havent seen any improvement yet.

if you could be alittle more informative on why you think its the psu, i'd be very grateful.

Edited by llama311, 01 September 2008 - 10:32 PM.

[starjax]

Yes and no. Because you have a good power supply is why it isn't crashing and blue screening. That doesn't mean it won't happen in the future as the system is used more. You have a good psu, it just isn't rated high enough in wattage. For anyone who games or had/is building a modern system (like yours) then I always recommend at least a 600watt psu.

Your system is overclocked. By setting it back to normal, not only do you reduce the power load, but you can rule out instability inherit to overclocking. If your system performance stabilizes, then we know where to focus our efforts.

The only other points I can make is to make sure that you are using the latest video card drivers. Also check to make sure your system isn't overheating.

[llama311]

i compared my normal 4870 scores with other people's 4870 scores in 3dmark06 and mine are well below normal, around half in sm 2.0 and sm 3.0. i also changed cpu clockspeed to 2.56Ghz and have seen no improvment in sm 2.0 or sm 3.0.

and i have re-checked drivers like 10 times

as for system overheating, i know that the gpu isnt overheating and the cpu isnt overheating, how can i check to make sure mobo isnt overheating?

Edited by llama311, 02 September 2008 - 09:09 AM.

[starjax]

well, you have two options

1)attempt to warranty your video card. They may or may not do it. They may even require you to upgrade the psu before they will do it.

2)update your psu and see if that helps before doing the above warranty.