Gainward 4850 512 MB Problem

[bokisb]

Hi All,

I have a big problem, and I wasted all my attempts to fix it... First my configuration:
AMD Athlon 5200+ X2
ASUS M2N VM HDMI Motherboard
4 GB RAM
ATI Gainward 4850 512 MB
250 GB 7200 HDD SATA
Power supplies: MSI 550 Pro/Chieftec 400 W tried with both
Samsung 22" 1680*1050

My problem is following:
In all games (tried: COD4;Fallout 3; LOTR Conquest etc...) I get sudden FPS drops. They run around 40+ FPS for 30 seconds, then sudden drop to around 5 FPS 5-10 seconds, then 40+ again.
And this goes all the time. Same thing happens in no regard to ingame resolution or graphic setting low/high. I tried drivers i got with the card, and the newest catalyst drivers.
I tried it on Windows XP Pro 32 bit, Windows Vista Ultimate 32 bit, and Windows 7 Beta 64 Bit. Same things happens in all versions of windows.
The temperature, when watched on Catalys control center never exceeds 52 degrees and fan runs at 6%. Tried manually putting fan to 100%, same thing.
I am all out of options, so If you have any suggestions, please...

Thanks

[bokisb]

and allitle addition... I just tried playin LOTR conquest on 640*480 with all LOW settings...and I had frame drops to 5 FPS

I am going crazy....

[pingu]

I doubt it's your power supply, because I used to have a similar system and never any problems. All I can think of is flashing your bios.

[InspectahACE]

I would probably use the bios flashing as last resort. I'm not familiar with AMD settings in a bios but if they have some sort of downclocking feature to conserve energy(like intel's speedstep) that might cause it too. Maybe even run MemTest on each stick of ram to rule them out.

[bokisb]

forgot to mention that I flashed BIOS also to the newest version Will try the Memtest and power saving featuers, thanks for the tips...