GTX260 BIOS Vmod Questions

[DavidNJ]

I have two GTX260 cards, a 192 and a 260. The 192 hits 756/1512/1152 with no to minimal artifacts; NiBiTor reports 1.12v. The 216 hits 729/1458/1250 with no artifacts, NiBiTor reports 1.06v. Both cards are 65nm.

Questions:

1) Does the reported voltage only affect the GPU?

2) Does it potentially affect the both the GPU and shader clocks?

3) Is the memory controller on the chip? Does it affect the memory clock?

4) Do all GTX280s come with 1.18v? Is that safe?

5) Do the GTX280s use the same fans speeds as the GTX260? Do they have any other cooling differences?

6) Is water cooling beneficial? The memory on the ATI 4830 and 4850 are often sold without any memory cooling. Even in a full coverage block, the memory on the reverse side of the board is air cooled. If water cooling is beneficial, is it beneficial for the memory also? That is, is it better to use a full coverage block rather than a Dtek or Swiftech solution which would have a water block for the GPU surrounded by an air cooled heat sink for the other components.

7) is there a significant risk updating the BIOS? In a SLI arrangement, can you always flash one card using the other to drive the video?

I have NiBiTor 2.22 and GPU-Z .2.21. I haven't downloaded the flashing utility...chicken I think.

Thanks for your help!

[DavidNJ]

No answers...my post is lonely...by poll in the video forum showed no on there doing anything...

[aussie-revhead]

I am interested in this also mate , so good luck finding answers.

:up:

[BenchZowner]

NiBiTor reports 1.12v. The 216 hits 729/1458/1250 with no artifacts, NiBiTor reports 1.06v. Both cards are 65nm.

Despite what NiBiToR reports, AFAIR the voltages cannot be adjusted by modifying the BIOS on the GTX 2xx series.
I might be wrong, you can try, but as far as I remember it's not working.


1) Does the reported voltage only affect the GPU?

The voltages "shown" in the BIOS and NiBiToR are only related to the GPU ( the core ), not the RAM or any other part.


2) Does it potentially affect the both the GPU and shader clocks?

Yes.
Raising the core's ( GPU ) voltage helps in overclocking for both the GPU Core & the SPs.


3) Is the memory controller on the chip? Does it affect the memory clock?

Adjusting the GPU voltage does not affect the memory clock alone.
In cases of "extreme" overclocking ( I mean way over 850MHz GPU Clock ) higher GPU Clocks might result in a bit lower memory clocks.


4) Do all GTX280s come with 1.18v? Is that safe?

I'm not sure, because I don't remember what my cards are showing in NiBiToR, and I haven't measured the voltage with a multimeter with the card in stock condition :p:


5) Do the GTX280s use the same fans speeds as the GTX260? Do they have any other cooling differences?

Nope.
Actually every manufacturer can ( and some of them do ) set different fan duty cycles in the BIOS, and I've even seen cards using different fan models.


7) is there a significant risk updating the BIOS? In a SLI arrangement, can you always flash one card using the other to drive the video?

When it comes to BIOS/Firmware flashing there's always a risk.Relatively small if you're experienced and have the skills and equipment to recover from a failed flash.

Yes, you can use the other card as a display device and flash the other card.

If you're thinking of fiddling with the BIOS and flashing the card, etc, read the guide (http://www.benchzone.com/page.php?al=geforce_overclocking_gui) first and the BIOS Flash failure "recovery" solutions just to be ready :)

( Ignore the guide's name, it's working for the GTX 2xx series as well, and the 9xxx series of course )
[ just make sure to grab the latest versions of NiBiToR, and nVflash ]

[CryptiK]

I can't be certain as I don't own a 200 series card, but I have read about guys reducing the voltage from 1.18v on their GTX280's to reduce the heat produced. It appeared to work for them as temps were lower and they could not overclock as far as on 1.18v (they set 1.06v for extra & 1.03v for 3D IIRC). I have no diea if you can increase a GTX260's voltage to 1.18v through the bios, though. You could potentially increase the 260 (core 216?) voltage to 1.12v like you std 260 shows, but that's just a guess. It's a bit of a grey area at the moment.

When you read the 260's bios in nibitor, what VID's does 'extra' have associated with it? That may give you a clue as to what is able to be set.

[DavidNJ]

I found this: http://forums.techpowerup.com/showthread.php?t=66296

[Splave]

2 of my 260s 55nm flavor came 1.06v and 1 1.12v
The 1.12v overclocked the best until I flashed the other cards to 1.12v and then they clocked better.
Not sure if they lower the voltage on better cores for better temps?

[DavidNJ]

GPU-z records the voltage in is sensor file if you turn on logging.

That would make sense. The more voltage the higher the voltage. I have a third card, supposedly the same as my second card, but with the higher voltage. So, as Bobbylite said, the are set by the manufacturer to get the specified performance.

My guess is marketing sets the production levels for each speed, and the cards are tested and binned for the desired speed with voltages being adjusted as necessary. A 1.06 card should OC better with more voltage.

I think the same thing affects memory. I haven't had a chance to test, however they are binning voltage for 1.65v for Core i7. A 7-7-7-24 DDR3-1600 cold very well be a 7-7-7-24 DDR3-1866 with 1.9v.