7900GT: Unlocking the Beast Within

[seanp789]

supposedly NiBitor 2.8a lets you adjust the voltage on 7900's through bios. can anyone confirm this?

http://www.mvktech.net/content/view/2069/37/1/1/

 

[Megatomic]

I don't know about voltages, but I was going to flash my XFX 7900GT with higher 3D speeds. With coolbits I'm running at 575/800 and it's RTHDRIBL and Quake 4 stable there. With the Zalman hsf I installed on it, the card stays nice and cool. Quiet too.

I'll look in Nibitor tomorrow and report what I see then.

 

[1Dark1Sharigan1]

Originally posted by: seanp789
supposedly NiBitor 2.8a lets you adjust the voltage on 7900's through bios. can anyone confirm this?

http://www.mvktech.net/content/view/2069/37/1/1/

So far that method doesn't seem to work because of overvoltage protection . . .

 

[zephyrprime]

Originally posted by: Steelski
I dont get it. I know the numbers are great for a cheap card. I know that most would agree that the increese is fantastic. But what is the standard voltage on a GTX? 1.4? is that not a bit high for a 90nm process? how long will this card last, does anyone care?

Well, the Prescott 90nm runs with 1.25v-1.525v stock so 1.4v isn't really high at all. Granted they're different processes so they're not the same but they should be pretty similiar.

 

[Elfear]

Shamino got some awesome results with that 7900GT. Nice to see he benched some games too.

Just a small word of warning. With the 7800GTs (not sure if this applies to the 7900GTs but more than likely it would, especially given the budget hsf and inexpensive price) the power circuit area needed some work to make them run semi-reliably with increased volts. ViperJohn, who is the voltmodding emperor, strongly recommended that I spend some time modifying that area with better heatsinks before I increased the voltage too much. In fact he basically refused to do the voltmods for me unless I paid the extra for further modifications as he didn't believe the cards would be reliable with just straight voltmods and watercooling. A smaller core bump, like 1.3V, probably isn't a concern but if you want reliability out of your card than I'd suggest waiting for more comprehensive documentation about these cards.

The 7800GT power circuit area was physically different than the 7800GTX, from what I heard, so the increased voltage that the 7800GTX used wasn't an issue.

I'm all about serious overclocking but I thought I'd chime in for those unfamiliar with hardware voltmods and the inherent risk involved.

Originally posted by: samusaraniv

I have a VF700 on my 7900GT SE so I bet I will get comparable results to that guy's heatsink/fan combo.

The Vf700 is a good hsf but just be aware that it doesn't compare to the massive copper hsf that Shamino was using. Might be just fine for the 7900GT though since that card seems to use so little power.

 

[samusaraniv]

Oh? Maybe I should try a gradual step-up from 1.3 then instead of jumping right to 1.5V. I also have OCZ copper ramsinks on the memory, and after 2 hrs of Oblivion last night, my card only got up to 55C with it clocked at 587/1880 (this is with the VF700 set to quiet, too!).

One question, if I do the conductive pen mod, can there be any undoing of the ink?

Also, no one has answered my question so I ask again.. when you draw the lines to ground for 1.5V, should you form the two lines into one or keep them separate?

 

[1Dark1Sharigan1]

Originally posted by: samusaraniv
Oh? Maybe I should try a gradual step-up from 1.3 then instead of jumping right to 1.5V. I also have OCZ copper ramsinks on the memory, and after 2 hrs of Oblivion last night, my card only got up to 55C with it clocked at 587/1880 (this is with the VF700 set to quiet, too!).

One question, if I do the conductive pen mod, can there be any undoing of the ink?

Also, no one has answered my question so I ask again.. when you draw the lines to ground for 1.5V, should you form the two lines into one or keep them separate?

When I tried 1.5v initially my system BSODs several times, which I why I changed to 1.3v and now to 1.4v.

 

[samusaraniv]

Originally posted by: 1Dark1Sharigan1

Originally posted by: samusaraniv
Oh? Maybe I should try a gradual step-up from 1.3 then instead of jumping right to 1.5V. I also have OCZ copper ramsinks on the memory, and after 2 hrs of Oblivion last night, my card only got up to 55C with it clocked at 587/1880 (this is with the VF700 set to quiet, too!).

One question, if I do the conductive pen mod, can there be any undoing of the ink?

Also, no one has answered my question so I ask again.. when you draw the lines to ground for 1.5V, should you form the two lines into one or keep them separate?

When I tried 1.5v initially my system BSODs several times, which I why I changed to 1.3v and now to 1.4v.

So since you changed back from 1.5 to 1.4, I assume that this means that you can remove the ink somehow?

 

[1Dark1Sharigan1]

Originally posted by: samusaraniv
So since you changed back from 1.5 to 1.4, I assume that this means that you can remove the ink somehow?

Yeah. Just use some acetone/alcohol and a cotton swab. Comes off in a few seconds . . .

 

[samusaraniv]

Nice! So to get 1.5V, do you combine the two ink leads into one stream or keep them separate?!?

 

[1Dark1Sharigan1]

Originally posted by: samusaraniv
Nice! So to get 1.5V, do you combine the two ink leads into one stream or keep them separate?!?

One stream. Separating them wouldn't achieve the same effect as you in essense "combining" the two circuits . . .

 

[Muhadib]

Is there a picture for the memory votage mod?

 

[samusaraniv]

Originally posted by: Muhadib
Is there a picture for the memory votage mod?

Here ya go: http://sg.vr-zone.com/?i=3330&s=2

I have done the pencil shading technique on the VMEM resistor and I was able to get my mem clock up to 940 from 870 using an eVGA 7900GT SE.

 

[zephyrprime]

Originally posted by: Elfear
Just a small word of warning. With the 7800GTs (not sure if this applies to the 7900GTs but more than likely it would, especially given the budget hsf and inexpensive price) the power circuit area needed some work to make them run semi-reliably with increased volts. ViperJohn, who is the voltmodding emperor, strongly recommended that I spend some time modifying that area with better heatsinks before I increased the voltage too much. In fact he basically refused to do the voltmods for me unless I paid the extra for further modifications as he didn't believe the cards would be reliable with just straight voltmods and watercooling. A smaller core bump, like 1.3V, probably isn't a concern but if you want reliability out of your card than I'd suggest waiting for more comprehensive documentation about these cards.

The 7800GT power circuit area was physically different than the 7800GTX, from what I heard, so the increased voltage that the 7800GTX used wasn't an issue.

I'm all about serious overclocking but I thought I'd chime in for those unfamiliar with hardware voltmods and the inherent risk involved.

With so much more power caused by this voltmod, some heatsinks on the power mosfets are definitely in order.

 

[Muhadib]

Bummer, that looks like it's not as easy as the 1.5v GPU pen mod.

 

[nib95]

I wish someone would just release a softvolt mod already

 

[Extelleron]

Originally posted by: nib95
I wish someone would just release a softvolt mod already

Wish nVidia would just allow for software over-volting like ATI.

 

[nib95]

Originally posted by: Extelleron

Originally posted by: nib95
I wish someone would just release a softvolt mod already

Wish nVidia would just allow for software over-volting like ATI.

Oh I see, so they dont actually even allow it

Does that mean, there may never be a softvolt mod for the 7900 GT? :Q

 

[1Dark1Sharigan1]

Originally posted by: nib95
Does that mean, there may never be a softvolt mod for the 7900 GT? :Q

They will first have to find a way around the over voltage protection. That's the only thing that's preventing a softmod from working . . .

 

[1Dark1Sharigan1]

So I'm at 1.4v now and doing 693/1820 stable, getting almost 5500 in 3DMark06 . . .

 

[Creig]

This is excellent news for the best-bang-for-your-buck crowd.

 

[Cookie Monster]

Originally posted by: 1Dark1Sharigan1
So I'm at 1.4v now and doing 693/1820 stable, getting almost 5500 in 3DMark06 . . .

:Q

Nice OCing.

 

[bokster]

Hey 1Dark1Sharigan1, nice oc! Did you just get the stock 7900gt? and what cooling are you using?

 

[nib95]

Originally posted by: 1Dark1Sharigan1
So I'm at 1.4v now and doing 693/1820 stable, getting almost 5500 in 3DMark06 . . .

Run me thru the easiest way to do this again please?

Also, what cooling are you using on the card?

 

[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. :\