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8800GT Volt mod success!

Last response: in Overclocking
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December 27, 2007 2:01:54 PM

Breaking news that isnt that important!

And now for the explanation... I was able to Volt mod my 8800GT with a 1Kohm Pot. I adjusted my idle desktop voltage to 1.26V. Under load it went between 1.29~1.3V( I used ATItool artifact scan, worst case scenerio type deal). This enabled me to increase my core to 770, shader to 1925, and my memory at 1000.

This gave me a whopping and I mean WHOPPING 124 points over my previous 700/1000 OC in 3DMark06. THATS IT ALL THAT STRESS, and constant image of my $240 card turning into a brick for a crappy 124 points. This volt mod is total buppkis,crap,waste of time. Not only that even with my Accelero S2 and turbo module when I scanned for artifacts my temp rose over 90C! When running 3DMark06 it barely hit 80C for a second. Absolutely not worth anything, not even the $2 and change I spent on the pot. Yet when I run it at normal voltage 700/1000 temps barely touch 50C during the run. +30C for not even 150 points? Not worth it.

Not only that, this website:

http://iax-tech.com/video/8800gt/8800gt01.htm

Is where I followed step by step. The mod does actually work. Before I would artifact anything over 720+ @ core. With the mod I was able to push the core up to 770 and the shader up to 1925. So it does in fact work, but the performance increase is NOT, at least in my case, as dramatic as the one posted on the site. After their OC/volt mod they were able to get well over 1000+ points in 3dmark06. At thier 'stock' speed they have a much higher SM2 score than me. Mine was about 49xxish, while their's was just about 55xx. Our SM3 scores were abaout the same. After their OC they achieved everything in the 6xxx area. Now I know their cpu is a HELL of a lot faster than mine, on average I get about 2500 cpu points compared to their near 6400 cpu points. I'm not sure if this effects their SM2/3 scores...but after EXACTLY doing EVERYTHING they mentioned I only achieved some points in SM2 and almost none in SM3. And I know the mod is working because the heat was a LOT hotter when overvolted, and I was able to run the artifact scan without errors at the 770/1925/1000 speeds(previously anything over 720 core would cause driver to stop responding). I verified speed with GPU-Z as well.

I cant explain why I saw almost nill improvement compared to theirs. It's not that but these are synthetic tests, which are usually more dramatic than what would be achieved during a real game. So I really dont think I would even see a noticable improvement with this OC.
In other words, if you are able to achieve 700 core 1000 mem just stick with that, it "ain't" gonna get much better. I actually desoldered the wires and removed them, leaving the pot sticked on for a little memento(not to mention the 3M sticky pad is sticky as hell) I'll post pics of the actually mod on the card in my system later on. It was fun and it 'worked' but not as well as I thought it would.
December 27, 2007 7:55:28 PM

Here it is:

January 4, 2008 11:53:04 PM

I haven't found the temperature to be a problem, but I'm running a bastardized VF900 with an 80mm Scythe fan at 1300rpm. What I did find was that I couldn't raise the voltage much above 1.2 without the card shutting down.

ATI Tool artifacts at 730 vcore OR 1000 mem OR 1900 shader. Running 700 / 975 / 1850 actully lowers 3DMark from ~11,700 to ~11,100.

Makes you wonder ... I'll play with it a little more and reverse the mod if I can't make it work better. I'm sure that will be *much* easier than soldering that bastard on there - those pins are awfully small!

edit 3DMark was low because I lost the processor O/C when the GPU reset. But so far the gain is marginal -
Related resources
January 6, 2008 2:50:05 PM

UPDATE: The eVGA 8800GT won't take much over 1.2v. With that it clocks to 740/950/1900 stable (so far ...). ATI Tool artifacts around 750 core. 3DMark06 is around ~12,350 with the CPU (E6750) running at 3.44. It seems that 3DMark score is largely dependent on a combination of GPU *and* GPU overclock. Between the two O/C's I get a boost of about 11% in 3DMark.
January 6, 2008 4:07:51 PM

I guess so, but for my particular situation, I just de-soldered the wires and stuck with my nice 700/1000 OC, I'm happy with that as I've read some people have a hard time getting there memory stable at 1Ghz. So I'll take it as it is, I'll maybe try again when I get a Q6600 when its cheap a year or two from now.

BTW nice rig.
January 6, 2008 4:09:08 PM

I doubt the prices of the Q6600 will fall much if any.
January 9, 2008 5:02:06 PM

If your hitting 90 degrees with the Accelero and Fan's you've got some serious issues.

I'm running the exact same setup as you, 8800gt, Accelero cooler with turbo fans and i've been able to take my card to 770 / 1050 / 1900 with just the software volt mod. The hottest my card gets is 42 degrees.......it idles at 32, even before the volt mod and Accelero cooler i had it clocked at 710 / 1000 / 1750 and the hottest it got was 63 degrees.

I've seen some big increases with this mod

Also testing has shown that taking the card past 1.1 volts is pointless. (stock is 1.05) Like i said before i gained an extra 60 / 50 / 150 by taking it to 1.1 v.

So no offense, but something is wrong here.
January 10, 2008 4:27:55 PM

LaN- said:
If your hitting 90 degrees with the Accelero and Fan's you've got some serious issues.

I'm running the exact same setup as you, 8800gt, Accelero cooler with turbo fans and i've been able to take my card to 770 / 1050 / 1900 with just the software volt mod. The hottest my card gets is 42 degrees.......it idles at 32, even before the volt mod and Accelero cooler i had it clocked at 710 / 1000 / 1750 and the hottest it got was 63 degrees.

I've seen some big increases with this mod

Also testing has shown that taking the card past 1.1 volts is pointless. (stock is 1.05) Like i said before i gained an extra 60 / 50 / 150 by taking it to 1.1 v.

So no offense, but something is wrong here.


I'm confused by your clocks, the core I get, the memory I get, but is your shader at 1050? or did you mean 1950? I had mine at 1925, if so OC shader to 1950 and check temps again. When I run the ATITool artifact scan my driver stopped responding and the temp went off the scale. My Accelero S2 can't be setup wrong I think, right now I idle at 38~40C depending on my ambient (usually 20C) and I've never ever go over 50 during gaming, I think it usally stops at 47C during gaming from some testing I've done. From my stock cooler it's a massive difference, I used to idle at 60C and load was well into the 80's. I wonder what happened....Please list your gains from the volt mod if yuo can in a 3dmark06 type of way with the breakdown of cpu/sm2/3. Thanks.

Actual is the shader one of those x2 deals? because 1050*2 would be 2100 shader, which is very impressive. The guide I listed mentioned getting close to that but had to add quite a bit of voltage considered dangerous.
January 10, 2008 6:45:01 PM

My shader is around 1800 (can't remember off the top of my head.....i'm at work)

My card idles at 32 degrees and never gets higher then 43. I'm going to get rid of the turbo fans and zip tie 2 120mm fans on it and see if i get any difference.

I don't have specific numbers on 3dMark, but i know i saw a good increase.......when i get off work i'll do more testing and let you know.

I've been playing COD4....Crysis and world of warcraft......i know wow isn't intensive, but it never drops below 60 frames :) 

Last night i played COD4 and it locked up on me once so i took everything down 3mhz just to be safe, but overall i've been playing Crysis no problems. I have everything set to high but no AA and i'm getting 40-50 frames. I can do x2 AA but it drops down to 28-35 which is to low for me.
January 11, 2008 12:35:47 AM

Well i have numbers for you.

Not a huge gain, but a gain none the less.

My rig is a 6400+, 2 GB memory, nothing insane.

My score in 3dmark on all stock settings was 11246

My score in 3dmark overclocked at i got a 11559 a difference is 313 points.

these were my settings.

740 core
1782 shader
1044 memory.

Now i'm not sure if this will effect score at all, but i did have my 2nd monitor running. I figured thats how i play games so i left it on.

All n All i overclocked my video card an average of 10%. It was free and easy to do. With my cooling setup i'm not going to worry about anything. Hell if i blow it up it means i get to buy a better one :-D

Also i got rid of those turbo fans and put 2 120mm fans on the S1 and i never saw temps over 39 degrees during my 3dmark run.
January 11, 2008 3:39:38 PM

Nice our performance is almost the same! Thing is though I don't have your score breakdown...this is mine:

3DMark Score 11399 3DMarks

SM 2.0 Score 5125 Marks

SM 3.0 Score 5439 Marks

CPU Score 2569 Marks
January 13, 2008 9:07:27 AM

Idk what you did exactly but the best way of voltmodding with 8800GT is changing a certain voltage in the BIOS from 1.05 to 1.1v and it allows you to get another 30mhz+ on the max overclock on most things.


If you don't see any improvement its likely a CPU bottleneck.
January 14, 2008 3:46:24 PM

Hatman said:
Idk what you did exactly but the best way of voltmodding with 8800GT is changing a certain voltage in the BIOS from 1.05 to 1.1v and it allows you to get another 30mhz+ on the max overclock on most things.


If you don't see any improvement its likely a CPU bottleneck.


Actually I forgot about the BIOS volt mod, sounds easy enough, Maybe Ill do that so I can get a little more on my core and shader.
January 24, 2008 8:01:17 PM

I've been playing around with this more and i've been able to break 12300 points.

I've been overclocking my 6400+ to 3.4 GHZ with a 285 FSB along with overclocking my memory and playing with my memory timing.

One thing is i've see a very big gain in my SM and HDR by overclocking my FSB / CPU and Memory I haven't even touched my video card. The card is still at 756 / 1824 / 1050.

January 25, 2008 2:01:11 AM

I dont get it though your mem is at 2100 but you say you didn't touch it? Nice score btw. What voltage are you putting on the GT?
February 19, 2008 12:49:38 AM

weird.. my 3D mark scored 11684 at stock speed.. after overclocked CPU and GPU... the score went to 13600+.. haha nice boost there
February 21, 2008 3:17:58 PM

bangity said:
weird.. my 3D mark scored 11684 at stock speed.. after overclocked CPU and GPU... the score went to 13600+.. haha nice boost there


This can be do to a much more powerful CPU. The system I compared to was getting around 6xxx for cpu score opposed to my 27xx cpu score. It kind of goes hand in hand, the more cpu power, the more it can process faster overall. But still for a budget build consisting of $155 in rebates (which I finally all received) and this cheap-o E2180 @ 3Ghz I can't complain to much. But at the resolution of 1920x1200 I play at the limitation mostly becomes the GPU rather than the CPU. I only have the demo of 3dmark06 so I can't run the higher res.
February 28, 2008 1:14:30 AM

Well I got my new monitor and decided to see if the volt mod would help at a resolution of 1920x1200. And the verdict is....better than at 1280 but still IMO not worth the time if your thinking about it. Overall I noticed a 2.16% gain with 750/1915/995 in 3DMark06 compared to my stock voltage 710/1775/995 setting. Again a bust. I'm still unsure if it's because of my 'weak' cpu (E2180 @ 3Ghz) but I know for sure in my case this mod really does not seem worth the time. If/when I get a Q6600 and @ it over 3Ghz I'll see if I can get some results, but that will be awhile from now...
March 9, 2008 1:22:51 PM

core clock helps mroe then shader clock
March 10, 2008 10:56:32 AM

well the temp difference is becuase you put 1.3v on the core so thats goign to increase the temps loads compared to the other guys 1.1v. maybe you could try lowering the voltage and checking if it is stil stable.
personally i just got a 8800gt for £110 and im going to try putting a accelero s1 and flash the bios but all in due time
March 10, 2008 2:29:44 PM

sex_monkey said:
well the temp difference is becuase you put 1.3v on the core so thats goign to increase the temps loads compared to the other guys 1.1v. maybe you could try lowering the voltage and checking if it is stil stable.
personally i just got a 8800gt for £110 and im going to try putting a accelero s1 and flash the bios but all in due time


Under load the voltage hit 1.3V but the default to assume is under Idle, either way however it's quite a bit more voltage and In reality the reason why I went to my non-volt-mod OC was because there was hardly any synthetic gain or a real world gain from the two.
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