Nvidia bios volt moding...NOT Working!

Hi all;

I've recently sli'd my BFG 8800 GTS OC 512mb
anyhow, I planned on voltmoding the cards using Nibitor , the voltage read for my gpu's was 1.15V ,, I changed that to 1.25V, saved the bios and flashed using nvflash in windows xp 32x

Then after restarting the pc I checked using aida64 , and nibitor itself that the voltage was indeed 1.25V ....
Time to check the difference using gputool, the shocking discovery was to find that there was absolutely no difference in the max speed the gpu/mem can reach

my question....what went wrong? how can I get more from those cards?
*I did not change any other settings in nibitor, just the voltage.
* temp went up more than what it would reach when i oc with those settings (780gpu , 1112 mem)
* I found something called gpu vcc in aida64 which was around 3.3v...what is that and is it related to this issue?

Edit: something was pushing me to change the voltage upto 1.3 but i hesitated not to damage the cards

Unfortunately, you have to do hardmods to get more voltage out of the older cards.

Thank you for your fast response
so, no matter what I do with the bios modding it won't work with my cards?
is there a guide for hard modding?

Nope, BIOS voltage mods won't work.

Just follow that link to 8800GTS (G92).

You can adjust the voltage via the BIOS, but it is limited and already at the max. Iirc you can select from 1.00 (VID0), 1.05 (VID1), 1.10 (VID2), and 1.15v (VID3) via the BIOS.

What you were doing was changing the labels, not the actual voltages. You have to pick 1 of the 4 preset VIDs or it will default back to stock.

hmmm
at the guide I was following , the guy used (Tool > Voltage Table Editor) in order to add other voltages...which I had to do . ... I sat VID0 as 1,15 and add .5 on top of that for each of the rest VID

and after the oc was done, aida64 showed that the core voltage is 1.25V

anyhow, if what I did was wrong, can u give me a work around/guide cause i'm not good in soldering at all

You just changed the label or comment for VID0 to 1.15v. Just like writing Froot Loops on a box of Bran Flakes doesn't make 'em Froot Loops. VID0's (and the other VID's) absolute voltage value is hard-coded and can't be changed.

I even went so far as to add VID4, VID5, VID6, VID7 to the code as there was just enough empty room in the code to fit it, but there are only 4 values (probably a 2 digit binary representation), it's not possible to change them, and unfortunately, there is just no way to get around it.

I used hard-mods on my 8800GTS-512, and an HR03-GT cooler (you aren't going to get much of anything else out of the card w/o better cooling anyway), and had good results: 846 core/2268 shader/1274 mem.

Later w/ the same card I removed the mods, dropped the stock speeds via the BIOS to 600/~1500/1000, dropped the voltage to VID0 (1.00v) via the BIOS, and put a single-slot 8800GT-512 cooler on it. I used it in my previous HTPC, and it ran cool and quiet.

very interesting info...so I won't be able to modify the voltage through any code.
However, I can get my card mem to oc upto 2000MHZ right now without any modding just normal oc,gpu up to 770mhz.
I'm planning to water cool the whole thing so I would expect much more ocing when it is that cool (with the modding) right?

For clarification you have your RAM at 1000Mhz, but since it is Dual-Data-Rate (DDR) the effective speed is GDDR3-2000.

With water cooling and volt mods on the GPU and vRAM you can hope for results similar to mine or better...but as always it will be dependent on luck of the draw.

Since you can only get the vRAM to GDDR3-2000 speeds (1000MHz) I'm going to assume it's using Qimonda RAM. Some 8800GTS-512 cards come w/ Samsung RAM, and do much better. The Samsung RAM responds well to extra voltage...the Qimonda RAM actually does better w/ a lower voltage, and you have to do a different mod (vmem buck mod) to get the voltage lower vs higher.

When you disassemble the card look at the RAM chips and confirm who makes them.

My 1st 8800GTS-512 had Qimonda RAM and it only got up to 1044MHz (GDDR3-2088) after using the vmem buck mod. After a long hunt I got my hands on an 8800GTS-512 w/ Samsung RAM, and was able to get it up to 1274MHz (GDDR3-2548).

Tweaking this card out is a lot of fun, but before you buy custom blocks or anything like that you might want to weigh the cost/performance benefits of your endeavor. For the money you might spend on water cooling it might be better to sell what you have and put all that money towards a new card which is more powerful, more efficient, and has DX11 support.

I've opened this back up as this is what I'm trying to do.
Q. Has anyone had positive results on V-Modding GTX-460, 470, 480 and GTX-560Ti, 570, 580 cards. I'm also looking at trying GTX-660(Ti), 670, and a Reference Asus GTX-680 DCU II (8+6 pin power).
^ I'm using Fermi/Kepler BIOS Editor, NiBitor 6.06, and NVFlash 5.558.0.
I have had limited success with AMD/ATI cards. HD-7xxx/R9-280x to 1.4v-1.425v HD-5870/5850 I ended up Completely Corrupting the BIOS Chip.

Thank You

Here's a link to some modded BIOS's that might help out.

https://community.hwbot.org/topic/2...-bios-collection/?tab=comments#comment-104071