Default ATI-OVERDRIVE max limit on HD4650

No such thing. All cards will clock differantly depending on th equality of the GPU chip. They are all of a set quality but between point X and Y so a chip that passed testing at the higher end of the spec will clock higher than a chip that passed at the low end. Some chips wont Overclock at all and some even give a worse performance when overclocked compared to standard clocks.

Its down to luck of the draw. Best way of doing it i found is in ATI Tray Tools (free download) It has a built in OC utility in which you can set the allowable amount of artifacts/graphics glitches and i usually set it to 5. It will then clock the card upwards untill this target is reached. Drop the clocks back about 5 Mhz and you should have a decent OC. You can of course try and clock it higher yourself as long as you are prepared to keep adjusting and re-adjusting the settings when the card falls over. keep an eye on your temps as this is a good indication of things being about to go wrong.

mactronix

What make is the card ?

Mactronix

Have you actually changed the card BIOS or just the driver/overdrive software?
If you`ve just changed perameters in the software just reinstall the driver suite.

Well i have asked around and it seems that its possable to use a differant manufacturers bios as long as its the same chip and memory used.
Now this is a bit of a long shot but as i couldnt find any actual Palit Bios downloads i thought that at this point it may well be worth trying the MSI live update service.
http://www.msi.com/index.php?func= [...] od_no=1742

Im assuming your card is not working at the minuite or is it just that you cant OC it ?
If its not working and its a nothing to lose thing then if you install the MSI updater then if it does totally screw the bios you are no worse off.
The way i see it it will scan the card and either decide its compatable and update the bios for you or tell you its not compatable and so it cant carry out the operation.

Sorry i cant be of any better help

Mactronix

UPDATE: I posted my problem on another forum and this very kind person who happened to have the same (only Diamond not Palit) posted his BIOS, and like i guessed. it FIXED IT! thanks http://www.techimo.com/forum/graph [...] ost2944891