Bios mod for 5800NU
 

Is there a bios mod for the 5800NU to say the 5800U? I looked on mavke's site and didnt see one. I know its a rare card, but if someone has a 5800U I would appreciate the bios :) My card easily does U speeds, but would probably gain a bit from increased Volts.

Re: Bios mod for 5800NU
 

OK, I found the 5800U bios. Does anyone know aside from speeds what difference there is in this and the NU bios?

Re: Bios mod for 5800NU
 

Likely none- except for clock speeds and core voltage. What voltage does your 5800NU run at now? You said it will run 500/ 1000 with the original BIOS? I'm thinkig by flashing the BIOS you'd like to overclock it further, and if so, remember that these cards run quite warm so good cooling is essntial. You are also aware of the "clock-throttling" issue that these cards have with the 60-series Detonators, right?

Re: Bios mod for 5800NU
 

No, if you could fill me in I'd appreciate it. I am using the 52.16 drivers right now. I am stable at 515/1120 24/7, any higher and I get diminishing returns. That seems to be the peak for me.

Re: Bios mod for 5800NU
 

Do you mean that anything above 515/ 1120 seems to be pointless as in no gains are evident? Or do you get artifacts/ freezes/ general instability? What temperature does your card run at at these clocks? The "clock throttling" issue may be a factor in the older 50-series Detonators also, but I cannot verify. Basically what this means is that the drivers will clock the card down under certain conditions, eg. running warm. It became a real problem in the 60-series drivers as the card would downclock while running 3D apps. fairly consistantly- even casual gaming. The "fix" is to install Rivatuner, and allow overclocking of the "low power 3D" mode. Simply set this mode to the same value as the "regular" 3D mode and that will prevent the throttling...
Also, which type of cooler is on your card? If you have the "ultra" cooler (some NU5800s did) you should not have many problems with cooling- if you have the smaller cooler then temperature may become a factor over 500Mhz as that cooler was intended for only 400Mhz...

Re: Bios mod for 5800NU
 

The main problem with flashing a 5800nu to a 5800u would likely be a clash with memory types. Doesn't a 5800u use DDR3, and not sure what your 5800nu has ???

However, you could probably get more Core speed from your card by modding your bios to set GPU volts at 1.5, instead of its norm of 1.4v !

All you should have to do is use X-Bios editor and look for gpu volts look-up table binary string of "78 04 82 05 8C 06" and change it to "78 04 82 05 96 07".

Or of course, you could just use NiBiTor 1.8 and at "VID Mode" tab, set Voltage 3 to VID 7 !

However, remember whatever you do will likely increase temps. And good temp control was never a plus point with a 5800 card ??

Re: Bios mod for 5800NU
 

Both cards use DDR-2.

Re: Bios mod for 5800NU
 

For some reason, I had a vague feeling that 5800nu and 5800u cards used diff memory types.

However if they both use same memory type, then nothing to stop flashing a 5800nu with a 5800u bios -----> apart from ensuring the card has adequate heatsinking/cooling to cope with increased temps?

EDIT:

Just compared a 5800 bios with a 5800u bios and found speed tables to be same, 2D is 300/600, Throttling is 400/800, and 3D is at 500/1000.

So maybe temps wont be an issue unless for overclocking ?

Re: Bios mod for 5800NU
 

You are correct. The 5800 uses DDR clocked at 400mhz(800mhz effective) and the 5800U uses DDRII clocked at 500mhz(1ghz effective). Isn't DDR faster if clocked to the same speed as DDRII?

Re: Bios mod for 5800NU
 

Glad to know some of my brain cells are still working !

As I said, there was this vague feeling in the back of my mind that a 5800 used diff memory from a 5800u ------> which then obviously means you must not flash a 5800 with a 5800U bios !!!!!!

Also, I think DDR2 was supposed to be more overclockable and do more work per clock cycle, but don't believe it was found sufficiently successfull over DDR in vga cards to guarantee a future.

And although it is now becoming the in thing for new generation mobo main RAM, it is still proving less effective than DDR untill running at higher speeds, simply because the DDR2 ram chips have a higher built-in latency.

Re: Bios mod for 5800NU
 

I really don't think 5800NU uses DDR1, I'd like to see a link supporting that claim.

Re: Bios mod for 5800NU
 

DDR-2 has higher latencies... My 5700 had something like 21 25 14 7 8 in the bios.
If I try to lower them to typical DDR-1 it cannot even run at nominal frequency (450MHz for the 2.2nS modules used).

Besides I don't know if there are other unknown parameters in the BIOS to be taken into consideration. I suggest to try Omni Extreme Edit to modify the frequency in your card bios instead of using a bios designed for a different model