Overclocking std. 8800GTX, how much is possible?

qwwwizx · Rated PG Joined: 28 May 2007 Posts: 23

Hi everybody.

I am overclocking my std. cooled eVGA 8800GTX. I use Nvidia nTune to do it and it is pretty boring. I need advice on how to get higher?

Factory defaults is 575MHz @ Core and 900 MHz @ Memory.

I am stable on 600MHz @ Core and 1000 MHz @ Memory.

I am unstable on 607MHz @ Core and 1027 MHz @ Memory (rebooting after 2 minutes in 3dmark 2006).

I use 3dmark2006 to test stability.

How much is possible? and do you have any tweaks/tricks to go higher?

/Casper

**Doctor Feelgood** · Posted: Mon, 24 Mar 2008 13:56:39 Post Subject:

Sounds like the most likely cause is overheating... You don't want to upgrade the cooler? How about adding a fan in the area, like a 80mm aiming down on it something like a CoolIT PCI Cooling Booster?

qwwwizx · Rated PG Joined: 28 May 2007 Posts: 23

I guess you are right. I was thinking about doing some extra cooling. I can watercool it, but need some extra gear to do it.

In the end of the day today I reached 627@core, and 999@memory.

Supported by my q6600@3.6GHz i reached 14035 in 3dmark06.

How do people reach 18.000+ in 3dmark06?

qwwwizx · Rated PG Joined: 28 May 2007 Posts: 23

Now I got one of those Thermal Take TMG ND4 LCS water cooling adapters to put on my 8800GTX, but how should I fit it.

My water-cooling system got a big radiator with 3 fans on it. The pump should be ok, too.

As it is right now

Reservoir -> Pump -> CPU -> Radiator -> Reservoir

I suggest it to be

Reservoir -> Pump -> CPU -> Radiator -> GPU -> Reservoir

Since I only have one radiator I am a little lost in how to get it optimal?

qwwwizx · Rated PG Joined: 28 May 2007 Posts: 23

well!!!

I upgraded with liquid cooling now, and the temps is down to nothing. Incredible.

Idle at
GPU: 35c
GPU Diode: 46c
GPU Environment: 35c
GPU Memory: 35c

Fullload at ~ 50c
GPU: 47c
GPU Diode: 56c
GPU Environment: 44c
GPU Memory: 46c

I use Everest ultimate to log the temps.

BUT! I still cant go higher than 629MHz/999MHz with my OC?

Can someone explain this for me? I need to reach the 3dmark06 17.000 barrier. PLEASSSEEEEEE

**Doctor Feelgood** · Posted: Tue, 25 Mar 2008 19:04:03 Post Subject:

Might be all the card has to offer. Maybe take the memory speed back down to see if that is limiting the OC. Perhaps the core could go higher, but not the memory.

And while it probably doesn't matter, I would probably go:

Reservoir -> Pump -> CPU -> GPU -> Radiator

BeerCheeze · Posted: Tue, 25 Mar 2008 21:43:16 Post Subject:

qwwwizx · Rated PG Joined: 28 May 2007 Posts: 23

I was also thinking about using the Y connectors, but I didnâ€™t have any. Another way of doing it was like Thermal take wrote by using another radiator between the GPU and CPU.

My problem regarding the Y connector or the second Radiator option was that I live in Denmark. I might be the only over clocker here, because no water-cooling accessories are available in the shops. The fastest way to get water-cooling equipment here is to order it from Sweden or Norway, which makes the delivery time at least a week.

I am very impatient, so I decided to do it as mentioned in one of my earlier posts:

Radiator -> GPU -> Reservoir -> CPU -> Radiator. This way there is a long between the hot components as possible and it can cool of a little. My experience now is that even though the GPU have been cooled before the CPU, only running through the reservoir gives the cooling it needs. It is hard to see any temperature changes in the CPU temps after the GPU cooling have been added, so I am still running 3600MHz at the CPU with no problems.
My water-cooling gear is now a black Thermal Take Kandalf LCD chassis with a Thermal Take ND4 GFX cooler.

Still only 14.035 in 3dmark 2006 (trial version from the futuremark homepage)

Next step must be doing the Vmod on the 8800GTX.

1/2Baked_Alaskan

qwwwizx · Rated PG Joined: 28 May 2007 Posts: 23

Hi 1/2Baked_Alaskan

Thank you for your answer.
I have been thinking about that, and found different bioses. I am a little afraid though.

I am able to go to 629 MHz on the core, and 1020 on the memory and so by using nvidia software OC. If I put a bios on it, and the bios force the GFX to run 660 Core/2200 Mem and it the hardware really can't, then I my GFX is doomed or can I re-program the bios back in some way?

/Casper