8800GT voltage mods

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02-28-2008, 02:02 AM
scottc19

Havent got around to pictures yet, but managed to bench the xfx card that I brought back from the dead... hit 1720 in 3dmark06 :)
http://service.futuremark.com/result...eResultType=14
core 885, shader 2219, ram 1026, 1.56v ---for benching
q6600 @3.82 1.59

24/7 870/2100/1000 1.5
3.8 1.57
02-28-2008, 02:35 AM
NonDecepticon

Scottc: nice results, always great to see some hardware resurrected from the Xtreme graveyard :rocker:

Does your's have the Samsung mem? How does it respond to more/less volts?
02-28-2008, 07:45 AM
jason4207

Quote:

Originally Posted by r4st4m4n

I just downloaded it yesterday and tested the spike created when idle Vcore is 1.2V. But it seems Crysis demo make the voltage going higher than Aquamark 3 :rolleyes:
I've also tested 3dmark01 and the test 8 or 9 (can't remember exactly the name) is what makes the voltage going higher by far. While any other test including Crysis bench only make the voltage go up to +0.055, this test make the voltage jumps up to +0.08 :eek:

I'll try tonight to set idle Vcore at 1.35V and run the 3dmark01 test, if it doesn't make the OCP kick in, I think nothing else will and I'm not willing to go higher on voltage anyways.

Yesterday I was a little bored to run benchmarks, so I tested the stability by playing Crysis. So far it seems 784/1944 is stable at 1.2V. At least it is after 1+ hour of Crysis. :up:

The voltage may spike higher, but OCP relates to current, not voltage.

Try running AM3 w/ 1.35v idle, and see what happens.
02-28-2008, 11:54 AM
trans am

Any 8800gs vmod results yet?
02-28-2008, 12:55 PM
scottc19

Quote:

Originally Posted by NonDecepticon

Scottc: nice results, always great to see some hardware resurrected from the Xtreme graveyard :rocker:

Does your's have the Samsung mem? How does it respond to more/less volts?

No samsung mem, the mem on this card really sux tho :( i did the vmem buck mod and found best at 1.84. 1026mhz is not 24/7stable, it is barely stable enough to make it through 3dmark... it iappears to be 100% stable at 1k tho.
02-29-2008, 03:12 AM
largon

Complete GeForce 8800 GS/GT/GTS Voltmods for reference PCB @ techPowerUp!
02-29-2008, 03:33 AM
quake6

And how do I connect them? Like this? Or reverse end on resistor?
http://shrani.si/t/1p/NS/VU0nF3k/g92gtsocps.jpg
http://shrani.si/t/2o/Wu/30y80R6L/1/qm-r-007-carbon.jpg
02-29-2008, 04:15 AM
BulldogPO

Could someone measure their card´s Vgpu and Vmem mods resistance with everything soldered. Measured from soldering points.
02-29-2008, 05:21 AM
largon

quake6,
It doesn't matter as resistors work both ways.
02-29-2008, 07:00 AM
r4st4m4n

Quote:

Originally Posted by jason4207

The voltage may spike higher, but OCP relates to current, not voltage.

Try running AM3 w/ 1.35v idle, and see what happens.

Indeed running AM3 at 1.35V is the winner :p:

It could complete the test at 846/2106 @ 1.3V idle (spike at the end going slightly over 1.35V) but it couldn't at 1.35V idle. At the end of the benchmark the voltage went slightly over 1.4V and it did trigger the OCP.

Anyway 1.3V idle is good enough for me ... at least for the moment ;)
02-29-2008, 08:53 AM
jason4207

1 Attachment(s)

Quote:

Originally Posted by largon

Complete GeForce 8800 GS/GT/GTS Voltmods for reference PCB @ techPowerUp!

Excellent write-up! :clap: :up:

Bookmarked for future reference.

I did notice that on the reverse vmem mod you used a different location for one of the solder points than the one VJ showed me (shown in yellow below). But, it may be that VJ's solder point, and yours are electrically the same.
02-29-2008, 09:03 AM
aoch88

Sorry but what does "reverse v-mem" means?
02-29-2008, 09:18 AM
jason4207

Quote:

Originally Posted by aoch88

Sorry but what does "reverse v-mem" means?

It means lowering the vmem voltage instead of increasing it. Read the guide and it will explain it better.
02-29-2008, 10:48 AM
Masure

Hi guys,

I don't have a VR but a 470ohms fixed resistor, could someone tell me what would be the vGPU with that res ? I'll solder if it makes me get something like 1.2-1.35v.
02-29-2008, 11:17 AM
Shocker003

1 Attachment(s)

Quote:

Originally Posted by wittekakker

VGPU in BIOS is set to 1,05V. I saw 1,1V is the highest possible value, maybe it works and boosts your overclock 2% :)

Made modbios via Nibitor, here is the zipfile, use at own risk.

Why void the warrant for these vga cards:eek:
All you guys need is Nibitor, it will save you a lots of stress. 1.5v can be done without pencil or soldering resistor. Read out your cards bios with the said program, go to tool and use the voltage editor, to choose your volts. Then flash your new bios with a bootable disk(floppy) with nvflash exe.
Pros: vga card is overclocked without using riva and ati tool, less load on cpu and rock stable ocs, while gaming and benching:yepp: .
Think about it and am ready to help out if someone wants to give it a shot.
02-29-2008, 11:39 AM
Renegade5399

Farthest you can BIOS volt mod is 1.1v, no matter what you set it to.

Please read all of this thread:

http://www.xtremesystems.org/forums/...d.php?t=164242
02-29-2008, 02:20 PM
Kabauterman

have someone a link to a simple understandalbe picture for 88GT (Rev Design) OVP mod???

There are so Many other Pictures and threads and my english is not so good
02-29-2008, 02:24 PM
quake6

Just do vgpu and OCP,OVP isn't required
02-29-2008, 02:32 PM
Kabauterman

what is OCP for 8800 GT i have only see the OCP Pic from GTS
but the GT hasn't all of this resistors
02-29-2008, 02:49 PM
EightyDuce

Quote:

Originally Posted by Kabauterman

what is OCP for 8800 GT i have only see the OCP Pic from GTS
but the GT hasn't all of this resistors

For OCP mod on the GT all you have to do is solder (in parallel) a 3.8-4.2K Ω SMR across the SMC next to the 78X chips. It's just like the GTS only there is 2 SMCs on the GT vs 3 on the GTS due to having one less phase on the GT.

Here is a pic:
http://img.photobucket.com/albums/v7...0stuff/OCP.jpg

Let me know if you have any more questions.
02-29-2008, 03:03 PM
Renegade5399

I am doing this mod tonite. I am SO close to 900 core, it's disgusting. I can get 880 on 1.35v load, but the card will cut out at the end of AM3 due to OCP.
03-01-2008, 01:54 AM
Ceph

Hi

I did the vgpu, the reverse v-mem and the OCP mod weeks ago. My Card does 753/1782/1053 (Core/Shader/ram) at 1,13V Load. No Artifacts in ATi Toll and no reboots or graphic errors. Also 792/1890/1053 at 1,17-1,18 are stable in crysis for a day playing. Now i set the voltage at 1,21 Volt Load and the card got unstable in crysis. With every voltage I got over 1,19V Load the card craps out in Crysis. So I tuned up the voltage and tune down the Clocks on stock, but it didnot work. Should I do the OVP Mod to get over 1,19V ? Thank you ceph
03-01-2008, 02:00 AM
quake6

Just do OCP,OVP hit the card only at 1.7v as far as I know
03-01-2008, 02:14 AM
Shocker003

Quote:

Originally Posted by Renegade5399

Farthest you can BIOS volt mod is 1.1v, no matter what you set it to.

Please read all of this thread:

http://www.xtremesystems.org/forums/...d.php?t=164242

I will make a deal with you send me your bios and the equally write out the settings you want, just core speed, mem speed and what voltage you need. I will mod your bios with these new setting and i will asure you they will work like a charm.:yepp:

I modded a BFG 8800 GT 740mhz core, 1835 shader and 1000mhz mem at 1.3v and i don´t want to push it further becos. the card don´t belong to me(father inlaw).
03-01-2008, 03:28 AM
r4st4m4n

Quote:

Originally Posted by Shocker003

I will make a deal with you send me your bios and the equally write out the settings you want, just core speed, mem speed and what voltage you need. I will mod your bios with these new setting and i will asure you they will work like a charm.:yepp:

I modded a BFG 8800 GT 740mhz core, 1835 shader and 1000mhz mem at 1.3v and i don´t want to push it further becos. the card don´t belong to me(father inlaw).

Did you measure the voltage with a DMM ? Could we know how you do that ?

Maybe you can put the explanation in the 8800 GT bios mod thread as it would be more its place ;) : http://www.xtremesystems.org/forums/...61#post2807561

I would be interested to know how you did since some people already tried without success ... even mavke, the developer of nibitor.

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