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Overclocking the go7900GS


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Having had my i9400 for a 5 whole days, and already having upgraded the CPU.

Now it's time for the GPU to get some attention.

The go7900GS on the i9400 comes clocked at 375Mhz Core and 507Mhz Memory, quite low compared to the go7900GTX or even the go7600 (475Mhz)

But nVidia have probably balanced speed and battery life and come up with the above.

The current go7900GS benchies arn't too shabby, so it seems to work.

Now Dell for some odd reason has locked the clocks, they cannot be changed in the nVidia Control Panel.

Well they can be, but have no effect, as soon as you check back the original speeds are back.

The i9400 has been around for about 10 months now and some good folk have made it possible to modify the BIOS with new Core and Memory speeds.

I'll go through the how to and the end results that I got.

This will only work for the i9400 :P but this should also be doable for other makes by someone with BIOS modding knowledge

Step 1

You will need 'Coolbit's enabled to get the overclocking page enabled, the modded INFs here have this on by default.

Run the nVidia Control Panel Overclock page, and find the optimal overclock.

Write down the numbers, as this should be your starting point.

Grab this boot ISO that 5150 Joker made.

Now make a bootable CD from this using your favourite CD burner (I used Nero)

Step 2

Now restart machine

Boot to the CD

Choose the 2nd line down when a choice appears

Press 'Enter' when prompted again

Now you're in DOS and you'll see a flashing cursor and not much more.

Type 'dir /w /p' and you'll see a heap of files named vxxxyyyy.rom and some others.

All the ROM files are BIOS's with different Core and Memory speeds and voltage mod applied.

Any ROM starting with a V has the 1.24v Voltage mod applied also, this is needed really for any serious over clocking (ie 475Mhz Core and beyond)

So when you see v6501200.rom you will get this (as I used on my machine to get the benchies)

v= 1.24v mod

650 = 650Mhz Core

1200 = 1200Mhz Memory (really 600Mhz as it's DDR3)

The whole idea is to choose the speeds you want and if you want the voltage mod to go with it.

It pays to start low and work your way up, until you get either too much heat or video corruption or you think that a certain point will be just far enough.

I would most certainly myself not run @ 650 Mhz Core all the time, just for benchmarking.

Now in the same directory as all those ROM files is an app call NVFLASH this what will upload the BIOS to the video card.

Step 3

So all you have to do is type in 'nvflash vxxxyyyy.rom' and then press 'Y' if you are sure.

It will then upload BIOS, takes about 15secs.

Now reboot and get all those Benchies ready.

I would suggest 3DMark 2k6 as this stresses the system to the max and it will show if you have gone too far.

Should the system lock or you see jagged lines or tearing on the screen then just boot back to the CD and try a lower setting.

With these modern GPU's they have 2 speed settings one for 3D and one for 2D, the process above ONLY mods the 3D setting so your desktop and spreadsheets etc will run as normal.

This also means that you can safely try the overclocking of the 3D clocks as the system will always boot to the 2D mode and you can just re BIOS a lower setting should the system crash.

In the olden days this would have made the video unusable :)


System as tested:

Dell Inspiron 9400/E1705

2Ghz Core 2 Duo (T7200)

2GB 667Mhz RAM

17" WUXGA screen

100GB 5400RPM HD

9Cell battery.

PA-15 150w AC-Adaptor (not standard but makes no difference unless you have a go7900 GTX or M1710)

System BIOS A04

Forceware 95.97

System was rebooted after each test.

Core 650Mhz (375 default) +73.3%

Memory 600Mhz (507 default) +18.3%

3DMark 2k1 - 30188 above 27455 +9.8%

The smallest increase of all the tests, this means there is nothing more to gain in DX7 the GPU is maxed out.

But CPU speed does make a big difference here as seen here

3DMark 2k3 - 20295 above 15264 +33%

A big increase so there is a little life yet in DX8 for the go7900GS

3Dmark 2k5 - 9334 above 6501 +43.6%

Even more of a jump here.

3DMark 2k6 - 5320 above 3592 +48.1%

And DX9c gets the biggest gain of all with the overclock


This is not for the faint hearted, probably only of use as bragging rights or to make a game play a little better if it struggles with the default clocks.

But once again now you have a choice.

Now we need other folk to do the same with other Overclocked locked GPU's to do the same and post their findings.

Keep an eye on this thread as I'll update it as new things are found, that is if you read down this far without falling asleep, in that case go to bed and read a book:)


Should you fry your Graphics card with trying the above, I know nothing about posting the above :)

You do so at YOUR own risk, the rewards are very good especially with DX9c games.

KEEP AN EYE ON THE GPU TEMPURATURE if this goes beyond 75 in testing with an ambient room temp of about 22degC I would lower the clocks

The GPU will throttle at 102degC but you can boil water with this and it may be too late by then.

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Just 1 question: Do you know which nVidia forceware version actually supports "Coolbits" and the overclocking page? I remember I tried some of the latest forceware and if I remember correctly they did not support "Coolbits". ie. when I use Coolbits to enable the overclocking page it doesn't work... The overclocking page just simply wasn't there!!! :) I don't really wanna install each of the forceware to test each of them out... So if anyone knows which forceware supports overclocking plz tell me... Also, I'm using a GeForce Go 6600 on my laptop. If someone knows which forceware works the best plz tell me also. Thx in advance.

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All Drivers support coolbits and the OCing page.

BUT some OEM's disable the page in the vBIOS.

Toshiba I'm afraid are the worst for this.

If you can find someone who has made a BIOS that has been OC'ed or has the OCing ability enabled then you won't even need the OCing page.

The BIOS's above don't need the OCing page as the Core and Mem speeds are fooling the BIOS into thinking that they are the default speeds.

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Ok... so all drivers support coolbits and toshiba disable OC pages... This may sound strange but I remembered coolbits used to work for me when I was using those old forcewares (such as version 8x.xx) on my same laptop a few months ago... I was able to change the clock frequency and stuff at that time... :) Anyway, thx for your help.

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In that case you need to enable the old Control panel again.

Edit the registry and look for this:


Now change these to 1




Now you'll have the old Control Panel back with the 9x.xx drivers that now have the new CP.

Hopefully this works.

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Since the I9400 is supposed to be the same machine as the 1705 do they use the same vBios for this flash?

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Since the I9400 is supposed to be the same machine as the 1705 do they use the same vBios for this flash?

They are the same, for some reason the North American market needs it to be called E1705.

I basicly have the E1705 as mine came from the US.

Si when I mention the i9400 it also includes the E1705

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Well the Nvidia driver "optimal" overclock came to 433Core 628Mem. I tried the 4301250.rom and noticed some graphic glitches. Mostly odd black lines stretched across the screen where shadows normally would be.

I went down to the next one lower 4301200.rom and it looks ok.

Is it normal to get such a low OC? I see files in there for considerably higher core/memory...

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1200 memory clock is my limit as well.

I take it you are using the ROM file with no 'V' infront of it.

The V ROMs are also voltage modded to 1.24v, this will allow much higher Core clocks to be reached.

You should be able to reach 600Mhz Core but the voltage mod is needed (any ROM starting with a V)

My extreme max OC is 650/1200 with the voltage mod

Any thing faster and the screen flashes.

The voltage mod makes no difference on the RAM stability.

BUT remember the voltage mod will at quite a bit of heat, KEEP an EYE on the temps (use the NV one for accurate one as i8kfangui is down 8degC and i9Kfangui is down by 4degC

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mobilenvidia - Are these steps intended for those with an i9400/E1705 and cannot access their OC page? I only ask because I am currently using the 92.91 drivers and can OC all I want from withon the CP (I have been able to with every driver from laptopvideo2go). I have a go7800 and it currently OC's to 362/879 when I use detect optimal, although i've had it up to 420/900 manually without artifacts, it was just getting a bit too hot for my liking.

So, if I follow your steps, will I see an even higher OC? Or is this just a work around for the locked BIOS? And will these steps work for me since I have a go7800?


Edited by cgande1x
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The above applies to the i9400 go7900GS which is OC locked.

The BIOS mods cannot be used on another GPU as it won't work

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  • 8 months later...

Two questions:

One: I am using I8kfangui to keep my fans at full speed, but I have heard that using i8kfangui stops your gpu fan from working, so were you running i8kfangui when you did this? and is the above statement valid?

Two: The overclocking window will not show up for me either, I tried what you said which didn't work, then I downloaded ntune which made the screen show up, but fan control was greyed out and there was no "find optimal clock frequency" option (I remember a while ago there was). But I have the same setup as you (only differences are my screen is 1440*900, I am running vista 32 bit, and my cpu is 1.83ghz core 2 duo.) If the resolution and cpu speeds won't make a difference to the optimal clock found by the utility, could you tell me what the optimal clock for you was? Just to be safe, I'll start slightly lower (though i won't overclock if my gpu fan is in fact disabled)

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One, from memory I used i9kfangui at the time as I preferred it over ik8, I now use ik8 x64 for Vista as there is no ik9 x64

Two, with ik8 the GPU fan works fine when setup full speed.

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ok and do you by any chance remember the optimal clock the control panel told you?

and also do you mean i8k? or if ik8 is a separate utility where can I download it?

sorry i'm very new to this

Edited by mynameisjohn
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You csn't overclock the 7900 via the control panel, as it's locked.

You can only do it with BIOS hacks.

I can' t remember the optimal settings as it made no difference with the locked BIOS (at the time)

i8k = ik6fangui was easier to abreviate :)

i9kfangui also exists but is not vista friendly

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  • 2 weeks later...

I have locked Go 7600 :) Is there any similar trick that i can use to overclock my gpu?

Thanks in advance.

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I have locked Go 7600 :) Is there any similar trick that i can use to overclock my gpu?

Thanks in advance.

Not unless there is a hacked BIOS or you can modify the BIOS yourself.

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