8800GT voltage mods

[dinos22]

waste of money. You would've been better off with this single 12v rail@ 41A
http://www.newegg.com/Product/Produc...82E16817139004

why?

[kiwi]

Nice .

I really want to do this mod, but not positive my cooling'll handle it. Take a look and let me know ? Also, should I sink the MOSFETs/etc.? I'm hitting pretty good clocks but I'm wondering if doing so would let me get further, especially if/once I do the vGPU mod.

http://img139.imageshack.us/img139/5736/8800nd12tc5.jpg

So ND1 fits 8800gt fine?

[Diverge]

So ND1 fits 8800gt fine?

you either have to mod the card by removing the fan connetor, or cut a notch in the heatsink of the cooler for the fan connector to sit in. I notched my heatsink. It's pretty easy, 2 cuts with a hacksaw.

[Eagleclaw]

Ahh didn't know you can notch the heat sink, got any pics?

edit: Just noticed your pics in another thread, you cut the copper part away is that correct?


thanks

you either have to mod the card by removing the fan connetor, or cut a notch in the heatsink of the cooler for the fan connector to sit in. I notched my heatsink. It's pretty easy, 2 cuts with a hacksaw.

[GoldenTiger]

Ahh didn't know you can notch the heat sink, got any pics?

edit: Just noticed your pics in another thread, you cut the copper part away is that correct?


thanks

Yep, that's what he did. If I had thought of a hacksaw (DOH!!!!) I would have done the same . It amazes me that I didn't for some reason.

[dinos22]

Yup, vMEM is definitely pencil modable and actually, vGPU should be too if you're careful. BUT a multimeter is a MUST for a safe vGPU pencil mod... The resistor is awfully tiny but it is doable, it's possible because the affected resistor has higher resistance than on G80GTS/GTX thus pencilling is easier.

The modable resistor for vGPU is the one marked with numbers 2 and 4, but I need measuments of the requested points to be able to calculate the target values for VRs / pencil resistance.

hmmm might be worth looking into

what sort of resistance should we be looking at for "safe initial test"???

[largon]

dinos22,
The problem with pencil vGPU mod is the low resistance between vsense and ground. Pencil vGPU modding was quite difficult on G80GTS/GTX eventhough their vsense_pin-2-ground resistance was 35Ω and since G92GT's vsense reads even lower (15Ω) pencilling becomes one step more difficult. 15Ω is awfully low to be penciled; it leaves very little room for error. Vsense-2-ground resistance could easily dip way too low consequently yielding a dangerously high vGPU.

But ofcourse, there's nothing that really prevents from experimentally pencilling the little bugger and measuring the resultant resistance, no harm done there. Just remember to apply pencil very slightly, and do not power up the card blindly without being sure the resistance doesn't get too low. And since I don't have the card I can't tell how low a resistance yields what vGPU. Hence, I have no idea what are safe resistances. We need someone who has done the VR mod to provide resistance readings...
People who have done the mod with VR: How low Ω between the vGPU mod solder points @ 1.2V / 1.3V / 1.XV?)

!CAUTION, UNTESTED MOD! READ THE ABOVE TEXT BEFORE MODDING!
Here's the pencillable resistor (optionally, you can pencil the one next to it on the right side):
!CAUTION, UNTESTED MOD!

!CAUTION, UNTESTED MOD!

[dinos22]

i think pencil modding *looks* to be a bad idea and maybe some extra loud warnings are necessary in posts referring to it i think

[largon]

Now, if some were to unsolder those two resistors and measure their values we would know if the pencilmod is safe... If we're in luck the other resistor would be low value (close to 15Ω) and the other considerably higher (some couple hundred Ω), if this was the case penciling the higher rated resistor wouldn't result in dangerous resultant resistance thus pencilmod would be safe.
Anyone?
:P

[T_M]

Dino, as a starting point any $10 30W soldering iron will do, as long as the tip is nice and pointy.
Get yourself some fine roll of solder and you are off and away

[nordicpc]

Very nice clocks guys, at those speeds we're looking at twice my G84.

I may have to be the first to try a pencil mod. Just try to change it a hair and see what happens. I'll let ya'll know if I get bored tonight.

At stock everything but fan speed, my XFX seems to like 733/18xx/1050 just fine, but another 10% wouldn't hurt if it's easy to come by.

[winbond]

Thanks for figuring out the volt mods.

I did this voltmod, and almost destroyed my card.
I'm actually surprised it is still working.
I have soldered many times before and have a good soldering iron but the wire i used was too thick and it ripped off couple times, taking the soldering points with it, and those resistors are really small too, but should be better next time around

ok so i turned it up to 1.35v and the stable overclock i got is 864/2106/970

the next step is 879.5 for the core and 2160 for the shaders, both unstable with this voltage

the ram is really bad, only got few mhz out of it, i can bench it @1025 but it's unstable in games

i wonder if it can go any higher with more voltage,
but i want to play couple games before i fry it

[dunn2953]

what are your temps and what type of cooling do you have?

[winbond]

watercooling with maze4 gpu block, heatsinks on ram (useless) and vregs,

idle 36 load 45

[npk]

watercooling with maze4 gpu block, heatsinks on ram (useless) and vregs,

idle 36 load 45

does the maze4 fits without any modification? also guys, so far what vgpu would you consider "safe" (please don´t say stock) for 24/7 on water?

[winbond]

yes, the maze4 gpu fits without any modification, 24/7 voltage? i don't know but i would say if everything is cooled well 1.3v shouldn't be a problem

[Renegade5399]

Guys, listen up. Running the memory at 2000 or higher for long period of time can be an issue.

See here:

http://www.hardforum.com/showpost.ph...8&postcount=13
And here:

http://i4memory.com/showthread.php?t=5030

Sorry if linking across forums is taboo, but it's important. You can slowly kill the memory running it over 2k.

EDIT: I have been debating on an 8800GT or the new ATI offering. Since my volt modded 7900GT was so good to me I think I will go with the 8800GT as well. Just wanted to get this post up for you guys.

[Garrett]

Just like I thought... 256-bit
Still these cards clock like crazy...hmmm tempting

[winbond]

just want to post an update, 849/2052 is the highest stable clock regardless of voltage, i went up to 1.47v

the 864/2106 is stable in crysis and benchmarks, but unstable in stalker,

my ram actually maxes out @ 956, im pretty sure the cards that came with 1000 ram clocks are unstable since its the same ram, voltage and timings

[winbond]

......ok , new discovery, at anything over 1.3v the card crashes, so i suggest you stay around 1.3 max for now, unless you have some super cooling,

(to me) it looks like some component on the card is overheating, my max overclock plays fine for 2/5 minutes then crashes. i have the heatsinks on all vregs and a big fan blowing on it so those are fine and my core is @ 45 so it's got to be something else.

if you are able you should test the temps of all the components on the card during load, i have no room to work with at all and don't have a good thermometer either

[d44ve]

I think I am going to have to give this a shot tonight. I will report back to you what I get.

[VETDRMS]

......ok , new discovery, at anything over 1.3v the card crashes, so i suggest you stay around 1.3 max for now, unless you have some super cooling,

(to me) it looks like some component on the card is overheating, my max overclock plays fine for 2/5 minutes then crashes. i have the heatsinks on all vregs and a big fan blowing on it so those are fine and my core is @ 45 so it's got to be something else.

if you are able you should test the temps of all the components on the card during load, i have no room to work with at all and don't have a good thermometer either

I had no issues running at 1.320v, but there was no need to as I am now 100% stable at 864/2106 at 1.281v. It probably varies by card, my loaded temps at 1.320v were 33C.

[Hazaro]

I had no issues running at 1.320v, but there was no need to as I am now 100% stable at 864/2106 at 1.281v. It probably varies by card, my loaded temps at 1.320v were 33C.

How many minutes stable is this?
Is it possible to run some under AtiTool 0.27?
Can you open up Crysis (Not benchmark, get some explosions in there) and play for over 15 minutes?
Any other games?

It just seems to good to be true, I am looking into doing one of these as I have a Accelero S1 cooler and my load temps are only 52C atm with 713/1728/948 clocks. (713 = Crysis stable [As in blowing up 40 trucks at a time and detonating 3 nukes simultaneously]) 740/1890/948 = UT3 Stable.

Of course clocks for Crysis are the only things that matter

That's for all the stuff you've ran so far.

p.s. Where can I order a 500 Ohm variable multi turn resistor cheaply from California

[VETDRMS]

[QUOTE=Hazaro;2539122]How many minutes stable is this?
Is it possible to run some under AtiTool 0.27?
Can you open up Crysis (Not benchmark, get some explosions in there) and play for over 15 minutes?
QUOTE]


30 minutes in ATITool, 6 hours in WoW at 1650x1050 8xAA, 30 minutes or so in NFS: Pro Street, Loops of 3Dmark05/06. I have done 6 loops or so of Crysis timedemo too, no artifacts/locks, ect..

[nelsmar]

500 ohm variable multi turn restistor: Radioshack. in their lil bins in the middle of the store that hold resistors led's etc etc. they should have some VR's there i bought a 10k and 500 from there.