Palit/Xpertvision /Gainward 7900GS 256MB vMod/ memMod - DONE!

[dracoonpit]

Hi guys,

I have a 7900GS 256MB from Palit/Xpertvision now, but it has a non reference layout. Searching for existing vmods was not successfull...

Maybe this card is similar to another non-reference layout for which the vmod is known?

Please have a look at the following pictures:


http://139.18.42.44/~pete/tmp/vmod_1.jpg

http://139.18.42.44/~pete/tmp/vmod_2.jpg

names of 8-pin bucks:
datasheet backside, left, the upper one: RT9214 (http://www.datasheet4u.com/download.php?id=528781)
datasheet backside, left, the lower one: LM358 (http://www.datasheetarchive.com/datasheet.php?article=2022274)
front, left, next to the gpu: 25P05VP - needed?

Standard-voltages are: 1.2V GPU, 1.8V mem

[Fr3ak]

Those 2 chips in the back left seem to be the chips you have to solder a vr to.
Whats their description?
VGPU and VMEM reading points are most likely on the legs of the "8ROM" things or the "1ROM" one.
Report back what voltage reading you get from those points.

[bbjayo]

OK, I've managed to get hold of one of these boards and a digital MM.

I've never used one before though so if someone tells me what to do, I'll post the voltages

bb

[dracoonpit]

Hi,

I'm also new to this stuff... ;)

You have to find the measure points for VGPU and Vmem first. The card must be running while you measure.

Most likely you'll find them, when you measure the voltage of the pins from the "Rom"-things (those big black ones).

[kolba]

hi, what's the maximum overclock with this board without vmod??

[xor59]

I've got a twintec version of this board.
My maximum stable overclock without vmod is 660/795.

[bbjayo]

Out of the box, I got 666/840

After a day or so, I started getting screen blanking and now can't get the mem to run much over stock. Core is good at 665 tho :confused:

[Knochenkotzer]

It's nearly the same layout that is used for the Palit/Xpertvision 7900 GT 512MB.
I think it'd make sense to work together.
http://www.xtremesystems.org/forums/showthread.php?t=98874&page=8

[bbjayo]

It's nearly the same layout that is used for the Palit/Xpertvision 7900 GT 512MB.
I think it'd make sense to work together.
http://www.xtremesystems.org/forums/showthread.php?t=98874&page=8

Good point. FWIW I just measured the vgpu point and got 1.3v and 1.35v in 3D mode. I guess that explains why these cards clock onto the high 600s straightaway. I'd love to know what's up with my mem tho.

Having said that, I'm on a tentative stability test at 720 :)

bb

[dracoonpit]

I found my max stable settings at 670core/784mem. But I did not check for core-slowdowns yet...

But back to topic - any new voltage measurements? ;)

[dracoonpit]

GPU-Vmod worked out:
xs (http://www.xtremesystems.org/forums/showthread.php?t=98874&page=8)
vrzone (http://forums.vr-zone.com/showthread.php?p=2591135#post2591135)

[dracoonpit]

Hi Guys, just want to let you know, that pencil-VGPUmod/memMod is working fine with my Palit 7900GS 256MB.

I penciled resistance down to 608 Ohm (629 Ohm Standard) and now the card runs perfectly with 685MHz GPU - (Geo +0). I guess my Chip is already at its limit, because without the Mod I reached 672MHz: Not that big jump...

I tested down to 592 Ohm - but I recieved Pixel-Errors, looking like when you have a defective Pipeline activated with RivaTuner. But I was able to run benches with 710MHz GPU. But not without artifacts... So I rose the resistance again to ~600 Ohms.

BTW: Does anyone know, where to find the measure point for the GPUcore?

http://img171.imageshack.us/img171/9464/gpuuy9.jpg


Vmem-Mod:

Is also working, but also without real improvement concering frequencies. I penciled from 1493 to 1421 Ohms - Resulting in 15MHz higher clocks.

http://img133.imageshack.us/img133/9928/memxz6.jpg


I also did several steps down to 1200 Ohms - but heavy artifacts occured. Seems, the Samsung-RAM doesn't like higher voltages. Or its already at its limit due to factory overclocking...


So - both Mods are working - but without the great results I hoped to see...

Finally (A64 San Diego 2800MHz, 2x512MB 255MHz):

http://img482.imageshack.us/img482/1899/05680785gy4.jpg


A detailed description in german can be found here: effizienzgurus.de (http://forum.effizienzgurus.de/f37/review-palit-xpertvision-geforce-7900gs-256mb-t296.html)

[TEDY]

I'm getting this baby tomorrow :)

[IluvIntel]

I have the Inno3D 7900GS, its based on reference design. Is there any software tools for increasing VGPU ?

[dracoonpit]

Changing voltages is not possible by software tools anymore... RivaTuner tells you, there is a difference, but there is not. Prooved by OC-test.


Only hardmods are working with cards from the 7-series and following...