7900GT: Unlocking the Beast Within

[aldamon]

Originally posted by: MuhadibIm playing it safe at 550 / 850 right now. I plan on buing a multimeter to see if I'm getting the voltage I think im getting. More ram sinks may be on my shoping list too.

This is the multimeter I've been using for a couple of years:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90899

We had a Harbour Freight in Raleigh, so I didn't even have to pay for shipping. After I bought one (well two actually), I brought it to work and compared it to a co-worker's Fluke for accuracy and it passed.

 

[Bullhonkie]

I haven't tried any voltmodding yet as I'm still on the stock cooler. This thing is loud (even at 2D speeds, makes me wonder if something is wrong with the cooler) and doesn't seem to cool very well.

I still managed to hit 590/860 but running rthdribl at those speeds puts the card at a blistering 84C after 5 minutes. Definitely need to grab a VF-700 or 900 to quiet and cool this thing.

 

[Hauk]

Planning to do the 1.4v pen mod to an EVGA 7900GT Superclock.

This card's stock voltage is the same as all 7900GT's (1.2v)? Want to make sure the Superclock isn't already ramped up. Don't want to go over 1.4v

 

[moonboy403]

i think i'm cpu limited, i only get 129xx in 3mark05 with my pair of gtx clocked to 675/860, seems like everyone's getting higher score than i do using only oced 7900 gt sli

 

[1Dark1Sharigan1]

Originally posted by: SteelSix
Planning to do the 1.4v pen mod to an EVGA 7900GT Superclock.

This card's stock voltage is the same as all 7900GT's (1.2v)? Want to make sure the Superclock isn't already ramped up. Don't want to go over 1.4v

Yes, all of eVGA's 7900GTs use 1.2v.

 

[TheRyuu]

Originally posted by: moonboy403
i think i'm cpu limited, i only get 129xx in 3mark05 with my pair of gtx clocked to 675/860, seems like everyone's getting higher score than i do using only oced 7900 gt sli

I get 13,760 in 3dmark05 without any voltage mod, thats @ 550/800 (1600 effective)

 

[MADMAX23]

Well, with 1.25v (0.5v mod with conductive pen) my 7900GT (550/1630 stock speeds), with the stock HSF, runs 100% stable at 590Mhz on the core...temps are 2-4ºc higher.
With 1.4v, it runs stable at 640Mhz...but temps are really high hitting 89ºc with ATITool but never with games, only 70ºc max...in fact my Gpu is a hot chip...so I think I'll have to get a Thermalright V1 Ultra to keep temps lower and be able to increase the core speed by 10 to 20Mhz at 1.4v...
I'll try 1.3v for you if you want...and 1.35 too...I love these GTs...
Right now I am running 24/7 at 590/1650Mhz with 1.25v on the core...

 

[MADMAX23]

Originally posted by: firewolfsm
ya, i'm a little scared, what about flashing the GTX bios? That should feed 1.4, i'm sure it doesn't work though.

No, I already did that, it does not work at all although the card will still work....

 

[MADMAX23]

Originally posted by: samusaraniv
So will a software update allow the voltage to be increased to 1.3V? Also, I just talked to a coworker of mine that did surface mount soldering stuff and he said that to remove the resistors as stated in that guide, you would need a magnification utility and be careful not to pull the trace (?). I have minimal experience with soldering stuff.

Does anyone know how hard of a task this would be?

Use a conductive pen and forget about hard modding the card....

 

[Bullhonkie]

I chickened out and only went for 1.3v.

My best OC and temps on the stock cooler were 580/870 and 42C/70C idle/load respectively.

Changed the stock cooler for a Zalman VF-900 and temps dropped to 33C/48C idle/load with no improvement in overclocking headroom.

Did conductive ink mod to 1.3v and bought myself a decent improvement in the core speed. Tried doing 650 for GTX speeds but the coolbits 'test changes' said it wasn't stable. Running at 640/870 now in rthdribl and load temps have gone up to 51C.

Kind of tempted to go for 1.4v now and see how much more it'll buy me. But my system is on 24/7 and this card will probably see usage for 3+ years so I'm leaning towards the conservative side of things.

Edit: This is on an XFX with stock clocks of 520/750.

 

[aldamon]

Originally posted by: nib95Can someone please link me to the memory volt mod. That earlier picture I saw is SO confusing and I have no idea about this.

Any help would be greatly appreciated.

I know what you mean. I'm not sure why they didn't draw the line in the picture. Use the 7900GT photo as a reference, but draw a u-shaped line around the resistor with the pencil like in the 7800GT mod shown here:

http://resources.vr-zone.com//Shamino/78gtvmod/3.gif

Use a cheap multimeter to confirm the voltage change. My first pass with the pencil netted me 2.1V and my second pass netted me exactly 2.2V.

 

[1Dark1Sharigan1]

Originally posted by: Bullhonkie
I chickened out and only went for 1.3v.

My best OC and temps on the stock cooler were 580/870 and 42C/70C idle/load respectively.

Changed the stock cooler for a Zalman VF-900 and temps dropped to 33C/48C idle/load with no improvement in overclocking headroom.

Did conductive ink mod to 1.3v and bought myself a decent improvement in the core speed. Tried doing 650 for GTX speeds but the coolbits 'test changes' said it wasn't stable. Running at 640/870 now in rthdribl and load temps have gone up to 51C.

Kind of tempted to go for 1.4v now and see how much more it'll buy me. But my system is on 24/7 and this card will probably see usage for 3+ years so I'm leaning towards the conservative side of things.

Edit: This is on an XFX with stock clocks of 520/750.

51C @ 640/870 is pretty good. My card goes up to 60C @ 700/1800 1.4v.

 

[aldamon]

XFX 7900GT XE
1.5V VGPU with CircuitWriter Pen
2.2V VMEM with Pencil
Sytrin KuFormula VF1 without the included RAMsinks installed

720 core / 1960 memory and currently artifact testing in ATITool

50 - 51 degrees after running rthdribl

It's stable in Oblivion at these settings. Higher memory speeds result in a black screen in Oblivion rather quickly. I'm going to let ATITool run all night and make sure I'm clear.

My core craps out in Coolbits above 720. Should I take that defeat at face value or is it pulling my leg?

 

[TheRyuu]

I have the 1.4 vgpu mod and the 2.2v on memory mod, and I have to say I'm pretty impressed. Right now I can do 640/1800 with out any artifacts in ati tool.

I felt the OCZ copper ram sinks on the memory, and they seem to get rather warm, is that anything to be concered about?
Also, I put some ram sinks on the mosfets just incase, and those things get pretty hot too.

 

[Muhadib]

Originally posted by: samusaraniv
Wo0T! Did the volt mod for the GPU to 1.4, and I am clocked at 693/1872!!

The only thing that sux is that apparently the guy who said the VF700 might not be adequate seems to be right, as before any mods clocked at 587/1740, the card didnt get above 55C on silent mode in RTHDRIBL. At the new OC'ed rates, RTHDRIBL gets the card up to about 76C in silent mode, 70C in normal. Not sure if I like the temps being this high, so I might have to get me a VF900 or just lower the voltage/clock rates. :\

I've got a 7900gt (1.5vmod) 690/1000 VF700 CU with AS5, Max 62C with RTHDRIBL. Maybe you could use some arctic silver?

 

[nib95]

I'm so envious.
Waiting on my new power supply before I voltmod my cards.
But I have all the stuff ready, VF900's, extra fan, zalman fan bracket, conductive pen, pencil, and AS5.

 

[Muhadib]

Originally posted by: aldamon
XFX 7900GT XE
1.5V VGPU with CircuitWriter Pen
2.2V VMEM with Pencil
Sytrin KuFormula VF1 without the included RAMsinks installed

720 core / 1960 memory and currently artifact testing in ATITool

50 - 51 degrees after running rthdribl

It's stable in Oblivion at these settings. Higher memory speeds result in a black screen in Oblivion rather quickly. I'm going to let ATITool run all night and make sure I'm clear.

My core craps out in Coolbits above 720. Should I take that defeat at face value or is it pulling my leg?

Gah! I was looking for something like ATITool to test for atrifacts because I didn't think it supported the 7900gt yet. What version are you guys using?

 

[AzNPinkTuv]

err what kinda conductive pen is this... just because of this im thinking on getting 2 7900gt's in my next rig for like 290 a pop when conroe comes out, clock to gtx and make it run sli which would be much cheaper then the x1950xtx

 

[1Dark1Sharigan1]

Originally posted by: Muhadib
Gah! I was looking for something like ATITool to test for atrifacts because I didn't think it supported the 7900gt yet. What version are you guys using?

Why not just continue using RTHDRIBL like you've been doing?

Originally posted by: AzNPinkTuv
err what kinda conductive pen is this... just because of this im thinking on getting 2 7900gt's in my next rig for like 290 a pop when conroe comes out, clock to gtx and make it run sli which would be much cheaper then the x1950xtx

It doesn't matter what kind, even conductive paint would work (you'd need to be careful though) The one I used I got at radio shack. The ink should be silver.

 

[AzNPinkTuv]

Originally posted by: 1Dark1Sharigan1

Originally posted by: Muhadib
Gah! I was looking for something like ATITool to test for atrifacts because I didn't think it supported the 7900gt yet. What version are you guys using?

Why not just continue using RTHDRIBL like you've been doing?

Originally posted by: AzNPinkTuv
err what kinda conductive pen is this... just because of this im thinking on getting 2 7900gt's in my next rig for like 290 a pop when conroe comes out, clock to gtx and make it run sli which would be much cheaper then the x1950xtx

It doesn't matter what kind, even conductive paint would work (you'd need to be careful though) The one I used I got at radio shack. The ink should be silver.

link?

 

[aldamon]

Originally posted by: AzNPinkTuv

Originally posted by: 1Dark1Sharigan1
It doesn't matter what kind, even conductive paint would work (you'd need to be careful though) The one I used I got at radio shack. The ink should be silver.

link?

http://www.radioshack.com/sm-see-all-needs-and-wants--pi-2104395.html

 

[AzNPinkTuv]

time to go to radio shack once my new rig is ordered

 

[samusaraniv]

Originally posted by: Muhadib

Originally posted by: samusaraniv
Wo0T! Did the volt mod for the GPU to 1.4, and I am clocked at 693/1872!!

The only thing that sux is that apparently the guy who said the VF700 might not be adequate seems to be right, as before any mods clocked at 587/1740, the card didnt get above 55C on silent mode in RTHDRIBL. At the new OC'ed rates, RTHDRIBL gets the card up to about 76C in silent mode, 70C in normal. Not sure if I like the temps being this high, so I might have to get me a VF900 or just lower the voltage/clock rates. :\

I've got a 7900gt (1.5vmod) 690/1000 VF700 CU with AS5, Max 62C with RTHDRIBL. Maybe you could use some arctic silver?

I made a mistake, I had accidentally combined the traces from the 1.3 pin and the 1.4 pin, so I was actually getting 1.5V instead of the 1.4 that I reported. Still, though, the card was getting substantially hotter at this voltage. I do use the VF700 in silent mode with AS5 and OCZ copper ramsinks.

I don't think I'm doing the RAM mod right, however, as I can not achieve memory clocks near as high as many people claim to be overclocked at. I can't get above 1820 or so stable.

So you're just supposed to draw a line (I'm assuming on the PCB) around the VMEM resistor with a sharp pencil, correct? Or are you supposed to SHADE the flat sides of the resitor on the left and right and "bottom" to form a U? I've attempted this a couple times, and either I can still only get up to 1820 or my card starts artifacting like crazy (in Windows even). I guess I'm just not doing it right..

A definitive picture would be very much appreciated..

 

[aldamon]

Originally posted by: samusaranivA definitive picture would be very much appreciated..

<cough>I already did a few posts up. This is how you do it. Note the pic is from the 7800GT mod, but the U-shaped line is the same:

http://resources.vr-zone.com//Shamino/78gtvmod/3.gif

 

[samusaraniv]

Originally posted by: aldamon

Originally posted by: samusaranivA definitive picture would be very much appreciated..

<cough>I already did a few posts up. This is how you do it. Note the pic is from the 7800GT mod, but the U-shaped line is the same:

http://resources.vr-zone.com//Shamino/78gtvmod/3.gif

This is the post I was referring to when I referred to the "U" shading method. I am still not clear..

Should I be shading the PCB or the flat edges of the resistor?

Either my memory sux and won't overclock to 1900+ or I am not doing this right.