5 Ways for a Better 6800 GT Overclock

I’ve been testing my GT a lot lately and was able to achieve a 473Mhz 3dmark2003 run on aircooling (http://service.futuremark.com/compare?2k3=3649129) which seemed pretty high compared to other GT overclocks ( http://www.xtremesystems.org/forums/...ad.php?t=45876 and http://www.xtremesystems.org/forums/...ad.php?t=49832 ). That’s why I wrote down my tweaks below. I hope it helps other GT users.
When I first got the card, it seemed to be an average card, it could do 415Mhz on the core and 1.1Ghz on the mem with stock cooling and voltage. And that was only benchmark stable. For games I had to drop to 400.
The card is a reference design GT with the mermaid on the cooler from Aopen. So, after weeks of tweaking and testing it could do 473Mhz stable enough for 3dmark 2003. As this overclock is achieved without any soldering or resistor pencilling, a lot of people should be able to reach comparable clocks. These tips could also be useful for other Geforce 6x00 cards.
So here we go:

1. Cooling
It’s obvious that if you want to overclock on air you’ll need better cooling, I’ve put a SLK900u AMD heatsink on it and a powerful fan. On previous generations of Geforce cards this was an easy thing to do, because the holes in these cards were large enough to fit 4 long screws. The placement of the holes around the GT core was different and too small for my screws but with some zipties I’ve managed to put the cooler firmly in place. The effect on the temperature was enormous of course. With 20°C ambient, the gpu never went above 40°C stressed. So the cooling was ok. Any cooler with lots of copper should be sufficient (NV5 Silencer for example).

2. Bios
With better cooling the next logical step is raising the gpu voltage from 1.3V to 1.4V, it can be done by flashing a new bios. You can extract your original bios with nvflash and mod it with Nibitor to 1.4V. Set 2D voltage to the same value as your 3D voltage for better stability. 1.5V didn’t help my overclock, but it’s worth trying. Get all the necessary tools, howto’s and biosses at http://www.mvktech.net/ (Mavke’s site).

3. Power
The biggest problem with GT’s is power, ultra’s don’t come with an extra molex for no reason. So how can we stabilize the power supply to the card, even with only one molex?
One option is to use 2 power supplies. The second PSU is only to provide power to the molex of the card. If you don’t want to fry your card, you’ll have to connect the green and the black wires from both PSU’s to make them boot up simultaneously. If you don’t have a clue what I’m talking about, don’t even try it.
A second way for stabilizing the incoming power is described here (thanks to Reject for the crazy idea, but it works): http://www.xtremesystems.org/forums/...ad.php?t=48577 . It gave me some extra 5-10Mhz.
Also, use clean powerlines, with no other peripherals attached. My Antec TC 550W has a molex at the back of the PSU, using this molex gave me the best results.
A serious overclocked A64 system (vcore > 1.75V) could influence your cards overclock (meaning less). I noticed this especially in 3dmark 2001.

4. AGP
Disable fastwrites
Set AGP voltage to 1.8V at least
Set AGP frequency to 81 (use clockgen).
Tested on a DFI S754 nf3 board and it helped me to get those extra Mhz and stability to complete a benchmark.

5. Rivatuner
Use Rivatuner for overclocking, it has 2 very useful options that can be enabled in the power user tab.
- Disable internal clocktest
- Disable any kind of throttling by forcing 3D performance clocks (http://www.vr-zone.com.sg/index.cgi?i=1582&s=3 thanks to Shamino)
Throttling problems are due to power or temperature. Most of the time it’s a power problem. Disabling the throttling mechanism will help finishing that precious benchmark without performance loss. That is, if you’re lucky, most of the time, it will just freeze and give you a corrupt screen. The Rivatuner author warns that disabling throttling can damage your card, so be careful.

That’s it, I hope it can help you reaching that 470+ overclock without any hardmods, it should be possible now if you follow my tips.

If you do want to hardmod your card, look here : http://www.xtremesystems.org/forums/...ad.php?t=48876
The vcore mod (thanks to shamino) : http://www.vr-zone.com.sg/?i=926&s=1
Vmem mod: http://www.vr-zone.com.sg/?i=1622&s=1

If you have comments or other good tips, let me know.

wow my mod worked
i think on a dual 12v rail psu the effects would be more evident
on my rivatuner the performance thing is greyed out, i thought it only worked for FX cards.
what bios do u use, i found best results on my stock sparkle

ure scores own me mate good job and nice post

this sounds pretty good, have to try it on my gt :D...
btw this autooverclocking / detect clocks via the nv-drivers is utter crap. my card usually craps out at ~420 core and when it craps, the mem is only at 1120 or so... and the mem can actually hit 1151 without hickup ... so i don't trust it all that much

hi guys, i cant find disable clock test in riva =o( there ist only bart, krusty, homer and so on... plz help me.

i have gainward power pack 6800gt

[IMG]http://img.photobucket.com/albums/v6...TON25/riva.jpg[/IMG]

here ya go matey

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Originally Posted by reject

wow my mod worked
i think on a dual 12v rail psu the effects would be more evident
on my rivatuner the performance thing is greyed out, i thought it only worked for FX cards.
what bios do u use, i found best results on my stock sparkle

ure scores own me mate good job and nice post

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Look in the power user tab in rivatuner. You must enable it.
I used the bios that came with the card and modded to 1.4V en 2d=3d

i cant find it =o( theres only name of simpsons...

Fantastic post.
I'd be tempted but given that I just fried a GT, I'll pass and take what it's going to give me at default volts etc.
My upgrade fund just took a hefty dent :stick:

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Originally Posted by rookiekiller

i cant find it =o( theres only name of simpsons...

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Try to reinstall, get the latest version at guru3d.com

HaLDoL: What do you get in 3d05 with 71.2x drivers?

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Originally Posted by Bradbury

HaLDoL: What do you get in 3d05 with 71.2x drivers?

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Only 6306 with 71.20

Compared to my 66.93 score:

http://www.xtremesystems.org/forums/...id=24130&stc=1

I've discovered that sideband adressing enabled gives you +200 point in 3dmark 05. Unfortunately I already had it on :)

My GT is sold, I have a BFG 6800u now. Will try to break some records with the ultra. :)

well, i modded my bios to 1.4v and could clock higher ~430 core, 1170 mem, but whenever i tried to run a 3d mark at those settings, i would - sooner or later - get a nice beautifully (?) colored checkerboard. no matter if i used 430/1150 or later on 410/1100 (what i can run for days with the default 1.3v bios). and of course this would lock up immediately .. or well.. i couldn't see much anything else, so i had to reset anyway. cooling wasn't an issue, as i mounted a 6800ultra heatsink, plus two additional fans. one 80mm straight above the aluminium core-cooler (after removing that thin aluminium coverplate) and another 120mm hitting on the 6800gts mosfet sink.

grrr crappola. btw i only upped the 3d voltage, so now i wonder what it is that is causing these checkerboards - even at clocks that work flawless with less juice. anyone got an idea?

/ed. spell-o-holic

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Originally Posted by sky

well, i modded my bios to 1.4v and could clock higher ~430 core, 1170 mem, but whenever i tried to run a 3d mark at those settings, i would - sooner or letter - get a nice beautifully (?) colored checkerboard. no matter if i used 430/1150 or later on 410/1100 (what i can run for days with the default 1.3v bios). and of course this would lock up immediately .. or well.. i couldn't see much anything else, so i had to reset anyway. cooling wasn't an issue, as i mounted a 6800ultra heatsink, plus two additional fans. one 80mm straight above the aluminium core-cooler (after removing that thin aluminium coverplate) and another 120mm hitting on the 6800gts mosfet sink.

grrr crappola. btw i only upped the 3d voltage, so now i wonder what it is that is causing these checkerboards - even at clocks that work flawless with less juice. anyone got an idea?

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Checkerboard crashes are due to power instability. Did you do what I described under power and agp? They may seem trivial, but they do help. Raise agp voltage/ frequency, disable fast-writes, make a double molex, etc... Test on a non-overclocked cpu first.

I dont mind modding a bios for you if you need the 1.4V/ 1.5V bios. Just shoot me a pm with card make and anything else important.

bookmarked ;)

i am gonna try some of these mods

Quote:

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Originally Posted by HaLDoL

Only 6306 with 71.20

Compared to my 66.93 score:

http://www.xtremesystems.org/forums/...id=24130&stc=1

I've discovered that sideband adressing enabled gives you +200 point in 3dmark 05. Unfortunately I already had it on :)

My GT is sold, I have a BFG 6800u now. Will try to break some records with the ultra. :)

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erm, ONLY 6306 with the 71.20's? what was the best driver regarding scores for you? i'm still running 66.81's as they gave me the most. but then again i didn't test them all. nv just has too many drivers to keep track of ;)

I've only tested 66.93 and 71.20 unfortunately.

From what I've seen, any of the 71.2X's are good. I would just go with the 71.20's the 71.24 and 71.25 seems to just fix SLI problems.

just out of interest, how come raising the AGP freq. helps overclocking the GPU? ala point 4.

I'd put power 1(b). :D

The 6800GT is a power hog when overclocked.

It also runs hot[ly] as hell, which is why H20 is so helpful to this particular card and why cooling is 1(a). I went from like 80C to 45C under load with water. I've never seen a CPU even come close to that kind of drop under water. Then again, CPUs don't ship with the woefully inadequate cooling that the 6800 series does. :rolleyes:

One thing is clear: If you have crappy power, you'll be very hard-pressed to have successful OCs with a 6800 series card. Now that I have my Powerstream 600 I should slip the 6800 GT back in and see how it goes. Mine would autodetect really high, but crap out under load, which was power starvation.

I know this is an OLDish thread... but I am having some issues OCing my MSI GTs in SLi... I think it's a power issue from my mobo not getting enough juice through the pci-e slots... I have an MSI k8n nei4 plat sli with a two NX6800GT's and a SilverStone Zeus psu... those cards have that nice copper cooler in them... I have put AS5 over the GPU, I have a 120mm fan right on the cards, plus a vantec fan card under the bottom card... they are stable at 375/1070 but not much higher than that...

does anyone know if it's possible to increase the pci-e voltage on a neo4? I am running the 5 beta 6 bios.

nice tweaks m8 i will try those :) cheers

I've given credits where needed. I'll be the first to admit if any of those tweaks weren't mine. I don't read overclockers.com, so I don't know if those tweaks were posted there.

1.4V is perfectly safe, my GT runs 6 months @ 1.4V and no problems. This is xtremesystems.org after all, and not I-am-afraid-I-will-kill-my-card-if-I-increase-the-voltage.org. Then this is not the site for you.

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Originally Posted by reject

here ya go matey

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Hey man are you using lightstep if so how do you like it?

Dragon

Also what about flashing to an Ultra bios if you card can do those speeds i have heard that if it can that it can also ne you a little better clocks and some better performance...

Dragon

Can someone make a thread like this for 6800 Ultras? :D

i know this has nothing to do with the 6600gt, but i also have an old fx5600 and i waz wondering if the software could be uzed to modd my fx5600 bios?

my PC'z

pc 1

3000+ @ 2.2ghz (70 x 8)
duel channel 1.5 gb of hyniz ram running @ 440mhz (2x 512 ans 2 x 256)
SATA 2x 200gb hdd (400gb )
asus a8v delux rev2
x800pro @ 550 / 520
sound blaster live 5.1
500w psu
big water (water cooler)

pc 2

p4 2.8 ghz @ 3.6ghz
asus p4p800 delux
1g duel channel ram @ stock speed (400mhz)
6600GT 128mb
40gb
350w PSU
big water (water cooler)


pc 3

(used as a HDD server)
semperon 2400 @ 2ghz
fx5600 (leadtek a310)
768mb ram ddr 400
120gb hdd + 5gb hdd ...LOL
350w psu

pc 3

1.6ghz p4 @ 2ghz
msi mainboard
512mb mem ddr400
r9200se 300/200
40gb hdd
350w psu

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Originally Posted by x800pro6

1.5gbof hynix ram 1 x 512 and 2x 256 (duel chanel)

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uh...thats 1024mb (1gb) of ram :rolleyes:

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Originally Posted by echow87

uh...thats 1024mb (1gb) of ram :rolleyes:

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sry no

2x 512 and 2x 256

Guys,

I'm running in 420/1140 rock stable with a nice performance!! But as I am doing the first day of tests in the card, I wanna know if there is any problem to run it on 1.3 volts (default).

In my ex-MSI 6800GT I had edited the BIOS, and set the voltage from 1.3 to 1.4 volts in both 2D & 3D.

Now the Leadtek is doing fine with these clocks, but I imagine that it's running with 1.3v. Is there any problem with that? If I should keep the clocks, it's better to edit the BIOS and set to 1.4v?

Thanks a lot!

AleX

Hey, i know this is old thread, but it beats making a new one :-)

I just tried edited the bios, upped the voltage to 1.4 but it hasnt made a difference in my OC. I could get 446:1250 max before and its still the same now. Is there any way of testing if its worked without a multimeter?

(BTW its watercooled)

How do i enable "Force constant performance level" option. It says disabled in the box and it is gray, i can not change it !

another little idea that can help people.

Download Gainwards "Expertool" program from that thing the "internet" and then you can manually set the fan speed of the card to 100%. Coupled with arctic silver 5, that will drop temps a bit. at 1.4v, the core will start getting WAY too hot past a point, but better than nothing.

I also want to know how you put the Thermalright on the GPU with zipties. I am guessing you removed the RAMsinks to do this?

thanks for your tips HaLDoL. Setting 81 mhz agp frequency helped remove artifacts. The sweet spot for my agp voltage was 1.65 volts though 1.8v seemed a little overkill and brought back the artifacts that raising to 1.65 got rid of.

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Set AGP voltage to 1.8V at least

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IS this the same as agp VDDQ voltage?

[edit]
Yes it is :) but i think 1.8 is a bit overkill, i have set it at 1.6
[/edit]

hi ya.
wow what a cool thread !
I'll try O'c this mother and see what happens.
I've beemn playing around myself. but not done any volt/BIOS mods yet.

here's my best score

http://service.futuremark.com/compare?2k1=8868012

28200 ishh ....

I've reently changed ram .. and thus HAD to change to a modded BIOS for my mobo. .... as yet it's not stable enough ... and my scores have gone out the window. :mad:
I'll try the mods and let you know. !


hey HaLDoL, you got any pics of the 478 HSF on the card ..??!?!?!?! :)
It would make me smile AND give me an idea how to do it on my gainward.

P.s i brought a Zalman FS-V7 Fatal1ty VGA Cooler, and at BEST i broke even !

Can I ask how many people have really seen cards die with 1.4v? Because I been running an le now with 1.5v for a couple off months and no problem at all besides the burning plastic smell if I forget to put a fan on the pcb ;)

Pc is running 10h a day atleast, 2d clocks flashed to 400-800 and 3d clocks set with rt to 450-900 most off the time, highest I benched with till now is 460/950 but ever since I went from stock cooler to a zalman v700cu my ram craps out above 920. Those tiny zalman hs's aren't near as good as I hoped even with an extra 80mm fan blowing over them and the pcb :(

i didn't know that the cards can die on 1.4volts.

I had planned to do this mod in the next 2 - 3 weeks.

the zalman fan is not very good for me. and i don't know which cards ( if any ) they make a real differeance over the stanard cooling.

1.4v on a gt would be less concerning then 1.4v on a le, diffrent circuitry iirc. I got a Zalman v700cu which didn't help oc much but is colder and more silent then the stock cooling.

I think I've squeezed the last drop of my GT before moving on to vmod & water

http://service.futuremark.com/compare?3dm05=1922744

P4P800SE unmodded semi-pat enabled
P4 3.2C SL6WG 12 CAP Costa Rica @ 3.91 1.6V cooled by Big-Typhoon
Mushkin XP4400 488mhz 2.5-3-3-5 2.85V
Leadtek 6800GT unmodded + Thermaltake Thunderblade 120mm 12V @ 450/1230 1.4V BIOS mod
AGP/PCI @ 74.67/37.33
OC'z Modstream 520W
84.21 WHQL drivers
LOD 3+

Any last minute's advice?

lol. Reviving this old thread I know, but with my new rig almost complete, I had to just try ragging more clocks out of my... WAIT FOR IT... 6800 LE!!! :doh:

:horse:

But still, I got 405mhz clock and 823mhz memory out of it. I've already unlocked the active / vertex pistols to 16pp/6vp. It's unlocked to a GT bar the ram differences of course!

It'll go to 415 / 835 in Rivatuner, but I'm not risking that as my mom is having this system after me! :p:

this may be Ot, i havent even read the thread yet but yu kno what?

you know how you know it wass a good idea to explore a new section of hte forum?

first thread i see is supn im in of dire need. i have 2 68 gts and wanan learn how to OC them since me and my computer have been twiddling our thumbs bored as heck nothign to do (since my config aint changed in a while). so maybe this will give me some extended life to the setup in the meantime. or else ima start cleaning my waterblocks again!

i have an agp BFG 6800gs with a zalman heatpipe cooler, the card is pretty good and stays cool (48C at idle/62C at load) it has suited me well, but i want to push some more out of it.

i have rivatuner and have un-locked the pixelpiplines and vertex to 16pp/6vp
from 12pp/5vp, there is a definte increase in my score when i run 3dmarks01 or 03

however when i overclock the memory and core i get worse results in 3dmarks tests, with the pp unlocked. i figured it was better not to overclock it and just have it at stock speeds and have the pp and vp unlocked.

so i kept it at that, but reading this thread got me thinking.

should i adjust the agp voltage and agp speed mhz in the bios???, maybe that will help me be able to OC the core and memory. im not sure how much to increase it by though becuase ive never done it.

at stock the bois says 66mhz and the voltage is at 1.5V

i have a asus K8N mobo, it has the nforce3 250 chipset

also what is aperture size? mine is set at 128mb.... it can go up to 256 and 512mb?

any body else have this card?

I ran stock cooling with 1.5V on a 6800nu for 2-3 years before it died :) Ran 450core no problem too.

BTW this thread really needs to be unstickied.

So bottom line, will an overclocked 8600 GT run on par with an 8600 GTS? :confused:

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Originally Posted by Judaeus Apella

So bottom line, will an overclocked 8600 GT run on par with an 8600 GTS? :confused:

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Your confused? :confused:

This is a 6800GT thread, not 8600 series! :shrug:

guys sorry to put this up..I have an Albatron 6800gt and a powerstream 420w,do that mod #3 worth in my case? I have the card connected to that black molex that the psu have for hdds and vgas..

about mod #4 81mhz is specific for 800gt or for nf3 dfi board?I guess it is more mboard related...
Would my soundcards run @81mhz agp?

Why is this sticky still around??

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Originally Posted by AC3421

Why is this sticky still around??

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Indeed!

"5 ways for a better Commodore x64" :D
http://www.cedmagic.com/history/commodore-sx64.jpg

Anyone know how I can overclock my Sega Mega Drive?

=D

Can we make that thread about OCing a 386?

Thanks.

I took my Atari 7800 out of the cupboard and cleaned the dust off it.

Now how do I make it run crysis?

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Originally Posted by Spoudazo

Indeed!

"5 ways for a better Commodore x64" :D
http://www.cedmagic.com/history/commodore-sx64.jpg

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:rofl: