Why can't I overclock further?

[XSlingerX]

Hi, this is my setup:

AMD Athlon 64 3700 OC'ed @ 2805 MHz (11 * 255)
Asrock 939 Dual Sata2
2 GB PC3200 RAM @ 200Mhz
LTD: 1020MHz
Voltage 1.45V (with voltmod up to 1.575)

It becomes unstable after 2805 Mhz. I have tried different multipliers but it gives the same result. I Tried lowering the LTD below 1 GHz but still no go. My CPU is 35 C on idle and 50 C on load, so its not too hot. I have tried upping the voltage and it still won't go further.

Any ideas on how to go further?

Thanks,
Slinger

[Vanquisher]

What motherboard is it and do you have a pci/agp lock? Whats your memory running at?

[XSlingerX]

What motherboard is it and do you have a pci/agp lock? Whats your memory running at?

Motherboard: Asrock 939 DualSata2
I am able to adjust PCI and AGP settings, if thats what you mean. I can set the PCI-E frequency to be asynchronous to the FSB.

[Vanquisher]

You need to have your pci at 33mhz and pci-e should be stuck on 100mhz. Whats your multiplier? or are you infact running your memory at 200mhz still?

[XSlingerX]

You need to have your pci at 33mhz and pci-e should be stuck on 100mhz. Whats your multiplier? or are you infact running your memory at 200mhz still?

Yep, PCI is at 33MHzand PCI-E is at 100 MHz. My memory is running at 200MHz.

[Vanquisher]

Sounds like a power issue, what powersupply do you have?

[XSlingerX]

Whta powersupply do you have?

I'm not positive on the name brand, but its a 500W with a dual fan. It's not a bottom line PSU, but not a big name brand either.

[Vanquisher]

Sounds like plenty but do you know the ampere rating on the 12v line?

[XSlingerX]

Sounds like plenty but do you know the ampere rating on the 12v line?

No, I'm not sure.

[Vanquisher]

there should be a label on the side of the psu it should say on there, looking at your rig now I notice you have 2gigs of ram and an overclocked x1900 chip so i'm sure its power lol as thats a pretty power intensive setup, its very important you have a good psu especially when you're overclocking

[XSlingerX]

So if anything, its my power supply thats limiting me?

[Vanquisher]

Most likely the case yes, I can't stress enough how important it is not to skimp on the power supply, if you go and spend money on an uber system and only get a midrange psu, then overclock its not a good idea . I'm not saying you have to spend a huge amount on a power supply but at least get one that's a good brand and has one 12 volt line for stability, with at least 25 amperes on it.

[XSlingerX]

Thank you very much for the advice Vanquisher