PDA

View Full Version : Unleash the 7900 GT to 800 MHz core and 2 GHz (DDR) mem


Pages : [1] 2 3 4 5

MUYA
03-30-06, 07:35 AM
http://www.vr-zone.com/?i=3437


Linky up there say dem boyz overclock dat 7900 GT to 800Mhz core and 2ghz memory for 50% increase in performance in FEAR and Quake4 ...at 1280 by 1024 with 4XAA and 16XAF!!!

a12ctic
03-30-06, 08:20 AM
very belivable, the cards seem extreamly underclocked with that tiny hs/fan

Joe Public
03-30-06, 09:51 AM
That's an excellent overclock. I'm aiming for a 7900GT when I upgrade my system, this is good news. :)

psuvette
03-30-06, 09:53 AM
I wonder if an arctic cooling 5 rev 2 would work on a 7900GT.

anyone know how rev 2 and 3 differ?

anticitizenzero
03-30-06, 09:55 AM
Yea but did you see how they did that voltage mod, i don't know **** about messing with the hardware on cards, isnt there a way to up the voltage in bios?

MUYA
03-30-06, 10:05 AM
You should check their website out as they have various guides to volt mod various hardware

Belarnion
03-30-06, 10:23 AM
Yea but did you see how they did that voltage mod, i don't know **** about messing with the hardware on cards, isnt there a way to up the voltage in bios?
No.
The only way with 7900GT is hardmod. But it's one of the easiest hardmods ever. :D

Marvel_us
03-30-06, 11:10 AM
Yea the GT mod is cake. I'm starting to wish I would've got one now.

Wonder if my GTX can go that high w/ some high end cooling.;)

CaptNKILL
03-30-06, 11:27 AM
Yeah, Im wondering about my GTX... Id love to squeeze some rediculous amount of speed out of it :D

littlegreenguy
03-30-06, 12:31 PM
same here. any ideas anyone?

TimeOut
03-30-06, 12:35 PM
I wonder if an arctic cooling 5 rev 2 would work on a 7900GT.

anyone know how rev 2 and 3 differ?

I installed my old artic cooling nv silencer 5 rev2 on my 7900GT last night.
It works fine but, I had to cut about half of an inch of its plastic air exhaust in order to make it fit in my case.

tieros
03-30-06, 12:41 PM
I'm going to grab a windshield deicing repair kit today and try out the 1.4 and/or 1.5Vmods. There's no way I'd ever do a solder mod to anything that costs more than 20 bucks, but this is a digital mod (just flipping a bit by grounding it as opposed to tweaking voltages), and it's easily reversable, so I gotta see what this baby can do :)

anticitizenzero
03-30-06, 12:56 PM
Where do I get a multimeter, do I need one to do this?

tieros
03-30-06, 01:00 PM
You shouldn't need a multimeter to do the basic Vmod.
The voltage is digitally controlled, and you're just flipping the +.2V bit "on".

Once you've done it, just do "detect optimal frequencies" from the nvidia control panel. If it goes way up, it worked :)

FraGTastiK
03-30-06, 03:36 PM
Amazing! That thing OCs like crazy I dont know if I could resist Vmodding my 7900GT if I had one, sooo much untapped potential left in that little cool core.Makes you believe that nVIDIA went super conservative with clocking those GTs.

If only partners were allowed to use higher voltages and made a factory OCed card based on that... :drooling:

Yet another winner scored by nVIDIA. GT line FTW!

anticitizenzero
03-30-06, 04:06 PM
So wait let me get this straight, on the website it says "a sharp pencil and shade the resistor to decrease it's resistance" now are they saying that you actually use a pencil, (the type for writing) and simply shade it in and it will actually increase the voltage? I'm new to this type of thing so this question probably sounds stupid

FraGTastiK
03-30-06, 09:40 PM
This should be called:

GeForce 7900GT
http://img215.imageshack.us/img215/1769/incredibles800042nc.jpg
EDITION

Super Fast Air Cooled Single Card.

Did I pimp it well?

tieros
03-30-06, 10:09 PM
So wait let me get this straight, on the website it says "a sharp pencil and shade the resistor to decrease it's resistance" now are they saying that you actually use a pencil, (the type for writing) and simply shade it in and it will actually increase the voltage? I'm new to this type of thing so this question probably sounds stupid

The resistor mod isn't needed for going up to 1.5V. It's also really easy to mess up. Graphite dust can end up places you don't want it :)

You can either solder a wire to make the connection, use a pen with conductive ink to draw the connection, or use a deicer repair kit from an auto parts store to draw the connection. I'm going with the last one since they are cheap and easy to get. I was going to get a kit today, but real life got in the way. Definitely tomorrow :)

agentkay
03-31-06, 05:34 AM
tieros, can you make step by step pics of the mod? Iīm especially interested how a deicer repair kit looks like (stupid language barrier) and how you applied it. Thanks in advance and if you canīt, its okay, no big deal. :)

Mr_LoL
03-31-06, 05:39 AM
I wonder how long the card will actually last at those speeds. I mean the temperatures are low so heat would not kill it. It might end up being too much voltage over a period of time.

TimeOut
03-31-06, 09:25 AM
I did the 1.45V vmod to my eVGA 7900GT Superclocked after I replaced the stock cooling solution with my old NV Silencer 5 Rev 2.

It is working at 650/1800 artifacts free but the temperature hits low 70s when playing BF2 @1280x1024 all settings maxed out.

I had to modified the card BIOS to increase the fan speed to 100% from the original 40% in 3D mode and I could reduce the max temperature about 3 degrees but, the once the fan hits 100%, it stays at that speed regardless I'm back to 2D mode which is supposed to run at 20%.

tieros
03-31-06, 11:28 AM
tieros, can you make step by step pics of the mod? Iīm especially interested how a deicer repair kit looks like (stupid language barrier) and how you applied it. Thanks in advance and if you canīt, its okay, no big deal. :)

Yeah, I'll be glad to. I just need to clear off a large enough spot on my desk to hide the mess :)


I wonder how long the card will actually last at those speeds. I mean the temperatures are low so heat would not kill it. It might end up being too much voltage over a period of time.

The GPU is the same one used in the 7900GTX, so it's designed to accept 1.5volts. If it's one of the chips that didn't pass at that speed and was binned lower, I'll know quickly and can just use a little achohol to remove the mod and go back to 1.2V.

Based on the number of successful mods, my guess is that speedbinning didn't come into play in determining GT vs. GTX :)

I definitely won't be doing a voltage mod to the RAM. It's already overvolted on the eVGA GT SC, so I'll leave it at 1640MHz and be happy.

GuOD
03-31-06, 03:40 PM
Single 79GT @ 660/910. perfectly stable/no artifacts. 1,4v paintmod

3dmark05 @ 10307
3dmark06 @ 5945

X2 1mb cache @ 2640
2gb ram @ 240mhz 3-3-4-8

tieros
04-01-06, 01:52 AM
Here's the pictures and results from the mod.

Here's the "before" shot of the upper left corner of the back of the 7900GT:
http://www.logicalshift.com/images/7900gt_before.jpg

Grounding the right leg of D508 increases the voltage to the GPU by +0.1V. Grounding the left leg of D511 increases the voltage by +0.2 volts.

I grounded both of them to raise the voltage from the default of 1.2 to 1.5.

Here's the "after" shot:
http://www.logicalshift.com/images/7900gt_after.jpg

The connections were drawn using conductive fluid from a car window defogger repair kit, which cost 10 bucks at my nearby auto parts store. It's used to repair breaks in the defogging/deicing lines on your rear windshield.

The fluid contains copper, and dries in a few seconds. I used a toothpick to paint it on, and applied three coats to make sure it was solid. It wipes off easily with alcohol in the first few minutes.

The proper way to do it is to make a mask or template and then apply the liquid so it forms clean lines. But daylight was fading, and my wife was taking the pictures outside to get even lighting without any glare from the flash. So I just drew the lines on freehand. Yes, I know it's ugly as sin :) I'm going to redo it properly this weekend, if I can pull myself away from Oblivion :)

And now for the results...


Stock for the 7900 GT: 450 MHz GPU and 660 MHz RAM
Stock for the eVGA GT SC: 550 GPU and 790 RAM
My default after swapping the stock HSF for a Zalman CF-700: 565 GPU and 820 RAM
My default after the voltmod: 650 GPU and 850 RAM
The highest stable OC in 3DM06 : 690 GPU and 900 RAM


The highest OC was 140/110 over the GT SC default, and 240/240 over the stock GT clocks. That's more than a 50% OC on the GPU !

I set the default at 650/850 so I could turn the Zalman fan back down to 5V silent mode.

Here's my 3DMark scores at the different speeds using an x2 3800@2400MHz. The card was set to High Quality mode in the control panel for all tests:

565/820: 06=5379 05=9624
650/850: 06=5863 05=9818
675/875: 06=6052 05=9990
690/900: 06=6133 05=10060


Many thanks to the guys at the XtremeSystems forum for all their hard work on this voltmod, and to nVidia for making such a kick-ass card!

Mr_LoL
04-01-06, 05:08 AM
Get another one for sli and you will be laughing all the way to the bank :D