i did it... Hardmod on my 8800gts 640!

Well i got bit by the overclocking bug again, always seems to happen on about a 6 to 8 month interval... this time it was the gfx card that was going to get a bump in clocks. Problem was i was already at my max 24/7 oc of 594/1458/1944 (max oc is 621/1512/1998 but i like to go one step under for 24/7 use)

So i set out to do vmods to it. Problem was that they were going to have to be hard mods, atleast for the vgpu as its voltage setting resistor is of such a small value, so i figured i may as well do both the vgpu and vmem mods legit. Man o man was it a PITA to solder to the vmem and vgpu resistor spots! I decided to do the mod similar to the XS and madshrimps guides but with a lil somethin extra.

Check it - as you can see i got all my stuff neatly ligned up at the back of the card. from the left to right in the pic we got a 20K ohm 20 turn VR for the vmem, the lil plug for my vmem and vgpu voltage read points (have a plug to plugs into it that goes to a 4pin molex. then the 2k ohm 20 turn VR for the vgpu!


The somethin extra... a 2 pole dip switch so that i can actually turn the mod completely off (disconnects the ground to the VR's)


And with it in my rig. Came out friggin bittchin if you ask me super clean


Well now onto clockin her!!! im hopin for 2 more steps in clocks... so and extra 54/108/108 mhz on respective current 24/7 max clocks.

Nice job man! Clean work, I wouldn't try that on my card lol, maybe with a better tip for my iron.

awsome!

good luck

still have the 6600gt with the cpu sink on it?

freeagent said:

awsome!

good luck

still have the 6600gt with the cpu sink on it?

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haha thnx guys...

messin round right now but my card no like to clock very much... still a work in progress on the clocks tho.

and yup still got the 6600gt agp with the cpu hs on it.

how much have your temps spiked with the mod on Stock cooling ?

I did the same mod to my old 8800gts 320mb .
I think somwhere in the 1.45v range on a moded stock hsf ran @ 720 24/7.

Very nice clean work. Hopefully you can get those extra mhz out of it now...

||Console|| said:

how much have your temps spiked with the mod on Stock cooling ?

I did the same mod to my old 8800gts 320mb .
I think somwhere in the 1.45v range on a moded stock hsf ran @ 720 24/7.

Click to expand...

gah i wish i could get 720ish on 1.45v... takes 1.45 to do 648 and the next step 675 @ 1.45v hard locks

from stock volts of 1.33 to 1.45 load temps gone up like 8*C

sweet! oh man it's a shame i still don't have that 8800 GTS rig..

ya so i have pretty much come to the conclusion that my card dont like to go much past 621/1512/1998 which it can do on stock volts.... vgpu voltage at 1.45 gets me 648 stable stock is 1.33v... but 1.5V dont get me 675 and 2.10v on the mem from 1.95 couldnt get me 2 steps up to 2106.... bah.

What are your idle/load temps?

That is hard core!!!

That makes a 478/479 pinmod look like shooting fish in fish tank with a shotgun! LOL

Wicked sweet mods!

Special7 said:

What are your idle/load temps?

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only like 8*C higher than normal... 60idle 85*C loaded with fan round 60%

Hmm, for the hell of it I would try to up the fan speed and see if it helps who knows.

Special7 said:

Hmm, for the hell of it I would try to up the fan speed and see if it helps who knows.

Click to expand...

ill give it a try tomorrow... i got kind fed up with its lack of clockability!

i hear you on that, my gts 320 was a much better clocker then my gtx was. well, i was able to run the core at 648 and mem at something like 940, and my gtx i ran at 621/1512/1008. when i had the 320 you werent able to clock the shader seperately heheh. but that dam gtx was such a let down in the ocing dept, it just sucked.

ya i wish i had an A3 core 8800gts 640... things do 702mhz on the core without vmods.

D*#@#! I was so hoping your mod would have yielded a hidden potential of this card! I would have been willing to tutor myself on hard modding with it. My A2 core 640 has been running 620/1399/1804 on stock voltage for some time now. It has been a long time since I played with it but if I remember right it did somewhere in the 650ish range and better than 1860 mem. Don't remember the shaders. I just backed off the OC a little when I stuck it a back up machine and thought nothing more of it.
edit: and I forgot to add "Kuddos on the great mod job!"

ya i am kinda bumbed ima play round with it again today n see what i can get but its lookin like ima just leave it at its bios's clocks ... i flashed it with my 24/7 oc a while back.

Better cooling should help. Obviously, you are nowhere near any kind of melting point, but these chips really like to stay below 50*C to get the higher clocks w/ more voltage.

Better cooling alone does nothing.

More voltage alone does little.

Together there is synergy!