What would happen if I flashed a vbios from a desktop GPU onto my mobile GPU?

I'm thinking about flashing a 9800 GTX vbios onto my FX 3700m. Though I would lower the clocks.

If that's not a good idea, what about just taking the vram timings from the 9800 GTX vbios and putting them in my 3700m vbios?

The 9800 GTX has ram that runs at 1100mhz, I have ram at 800mhz (can OC to 950mhz +). With the 9800 GTX timings, wouldn't I get a much better OC on my ram?

Pretty sure I could blind flash if it goes wrong (my notebook boots with a dead 3870 and I can hear the windows sounds).

Has anyone flashed a desktop GPU vbios onto a mobile GPU before?

 

I don't think it would work out well to try flashing it to the 9800 GTX bios.

Where is the BIOS you were thinking of? I want to look at it with a hex editor...

 

Here it is:
techPowerUp! :: VGA Bios Collection: Gigabyte 9800 GTX 1024 MB

What do you think about just taking the timings from it then?

 

Really not sure...

I think umm you should compare 285m and 280m vbios see if they have the same timings, because people have successfully flashed 280m to 285m.
You could take the timings from that.

Why are you thinking it would allow for higher overclock, I don't really understand it as well, but is it sort of the same thing as with ram timings and FSB overclocking?

 

Yes, I have seen a guide somewhere on the net which showed when you increase vram timings you can get a better OC on the vram. Also in the datasheet for my vram it says it will run at 1000mhz if you have the cas right.

I thought it would be a fun thing to test.

 

It will almost certainly not succeed. The memory timings will not work with your 3700. If you're running into an overclocking limit, changing the vbios will not change the physical nature of the chip that is limiting the overclock.

The thing you might try doing is editing the 3700M vbios. But flashing a desktop->mobile vbios is treading on very, very thin ice and could even cause you to get to an unrecoverable state, so be prepared to buy a new card if you try it.

 

Sorry for my stupid question... But what are mem timings? Is it how fast the Voltage travels around the VRAM?

 

Maybe there is something in the vram datasheet that will hint at the actual hex bits or something to lower the CAS.

I wish I had time to look up datasheets and stare at hex code right now, it seems like the most interesting things only come up in life when its most busy.

but if you have any ideas... and you just want to make sure it wont brick the card... I will sacrifice a broken card I have as a guinea pig, it doesn't run at full clocks but has no issues with lower performance modes.
Maybe I could actually sort of fix it by overclocking the low performance modes, I hadn't thought of that, not sure what could be wrong with it causing everything to work perfectly but the full clocks.

BTW its the exact same version you have.

..Or get a new EEPROM. I'm not convinced there have been more than a very small number of flashes that destroyed hardware. A bricked card in this case only means that the EEPROM is too messed up to accept a flash operation which can be bypassed with some hardmods.

 

Are you saying that if I provide you the vbios you will flash it

 

Yes. Not the 9800 gtx I don't think that will work at all. If you think you have a good idea of how to edit the timings and increase the CAS, I will try it.

 

Thanks for that, currently I'm working on the vbios (testing the timings with nibitors feature "test timings" button). Got artifacts with the last timings I've tried, so a bit of trial and error now.

 

I can't change the timings without getting artifacts.

nibitor tells me my timing set is nr. 5. But when I press test timings and get timings, they dont match the timing set nr. 5.

 

Well here is an FX 3700m vbios which has had it's timings substituted with those from the GTX 285m, I hope this works.