Clevo P377SM-A with GTX 980 (not M)

Hi everyone,
Some time ago I found a thread on techinferno when someone change the GPU core from GTX 980M to full GTX 980.
So I decided to make the same upgrade since I had SLI and one of my cards had cracked core ( cracked but working).
I bought a burned GTX 980 with a hole in the PCB(burned capacitor). I did repair it and the core itself was ok.
But cutting to the chase..
The transplantation seceded. Card has now 6 Vcore power stages and full GM204 core.
When I was testing it on HP 8760W everything was great. I could access to BIOS and normal Nvidia drivers was successfully installed. No problem with brightness control in windows.
When I put the card into my P377SM-A I do not have video in BIOS. Just black screen until windows boots up with the drivers. I changed the drivers. Mod it in a way that the 980M was installed. No luck.
Card is working great but brightness to max is pain in ....
Both the P377SM-A and the card has their Bios from Prema.

Any ideas how to solve the problem?


Best regards,
Chris

 

Might want to ping @Khenglish who is the member who authored such an upgrade.

 

Thanks for the info. I just wrote to him. Fingers crossed.

 

1) Newer nVIDIA drivers lack brightness control on some machines (tested on P750ZM/P770ZM/P770DM - latest drivers version with brightness control - 442). I dont know why, but it is a fact. Try older drivers.
2) Your vBIOS is wrong (980M with 980 core) so you need to try Clevo GTX 980 vBIOS at first, and if it not work - contact with @Khenglish.

 

I tried desktop 442, 441 and notebook 441. No luck. Should I somehow mod the drivers before?
I have Clevo GTX 980 vBIOS from here https://www.techpowerup.com/vgabios/190340/190340
I will give it a try tomorrow. I have the programmer so no problem in case of a failure.
But I think @Khenglish stated that it is not needed: So it actually works with the 980m vBIOS. I tried modding too soon. I just needed to reinstall the driver."
The card is working flawlessly except the brightness control and no video during POST.
I think I read somewhere that bios from P377SM-A has lack of some compatibility. Like not possible to put 1070 in. No problem on P375SM-A though.
I think that only Prema Bios could help.

 

What screen are you using? It sounds like you changed the display from LVDS to eDP. Clevo on SM and EM systems had separate brightness control circuits, which makes switching the display type in their laptops a headache.

You can't use a 980D vBios. The ram won't work at 7GHz, and idk what other incompatibilities there are. What you should do though is modify a clevo 980m vbios with the correct desktop core device ID. If I didn't already send you a copy, I can in a few days.

 

I have standard LVDS display. Nothing has been changed. Only the core.
In terms of a desktop ID it is like youres when you did the core change. There is no brightness control in the power panel. Like in all desctop cards. Driver do not detect the card as a mobile one so do not install the control. I gess.
Could you send me the copy?
Oh, and I found the bios wchich is on the card. It is Premia v2 980m bios.
Desctop 980 vbios did not work. Tried that by mestake. But I did not try mobile 980 bios. I put extra Vcore drivers and extra capacitors so it might even boot on 7Ghz.

 

With a vmem mod it might.

 

Cap mods would only add a few hundred MHz. 980m with stock vmem can do around 6.2 GHz at best. At 1.5V they can do low 7s. This is not relevant to the current problem though.

I am away from my computer with the device ID mod. I can get it to you tomorrow. I'd just redo the mod but I haven't dealt with remembering where the checksum is in a while.

I had no issues with display on startup. The device ID fix on EM series only helped with driver installation. It still displayed an image on boot. I only used eDP displays though.

You can try looking up the enablebrightnesscontrol registry mod, but I think that only works for eDP displays.

 

My old 780m did 7.4Ghz with vmem but my 980m did 7.1 stock config and 7.0 ish when I added the extra VRM modules (no extra bulk caps though).

 

Nice!!

I have tried enablebrightnesscontrol mod. Still no luck.
The P377SM-A itself definitely do not recognize the cards hence no video in BIOS. I think if we figure out that problem drivers will manage.
The HDMI output is working ok. But there is also one funny behavior. When I disable the cards in Device Manager or uninstall the drivers - black screen. On windows standard GPU drivers ( hence no drivers) - black screen. But I can still access the system through TeamViever from another machine and install new drives remotely .

 

I put a 980 mobile bios. Did not work. Black screen. Than I mod it to the same memory and core freq as 980m. Black screen. GPU was detected correctly by GPU-Z but the drivers did not wont to install (TeamViever ). So back to square one...

 

Success!!
How?
1 - We need a factory Clevo GTX 980M vbios.
2 - We need MaxwellBiosTweaker
3 - We need HxD Hxd Editor
4 - Load vbios to HxD and in search we are looking for HEX DE 10 D7 13 ( 2 places) and replace with DE 10 0C 13 (both of them)
5 - Load moded vBios to MaxwellBiosTweaker to generate new checksum.
6 - Using CH341A flash the newly cooked vbios.

Now everything is working. Video in BIOS and brightness in windows.

I cannot do that on Prema Bios because MaxwellBiosTweaker crashing on it :?
But MaxwellBiosTweaker do some power and clock mod so it might not be so bad option.

BIG thanks to anyone involved in this thread.

Now I will test the cards after some additional changes (more capacitors) and see if the SLI is working fine.

Next challenge?

P377SM-A with SLI GTX 980

Best regards,
Chris

 

That's going to be some strain on the power delivery to feed two of them so be careful.

 

Ha yes I would hit 280W from a single card at 1.2V. 980 is such a fun card to play with.

Congrats!

The core does respond nicely to more caps, particularly if you add them directly underneath the core. You can get around 40 MHz more. This is the most dangerous place to add them though. It's easy to make accidental shorts, and the ceramic caps die if you use an iron on them if the card is cold (heat difference across ceramic cap kills it, but even heat is fine). They short out to a few tenths of an ohm after they get powered on and you'll see very high power usage even at idle. You should be able to get 13 Mhz by playing it safe and piggybacking 6 electrolytic caps on top of the existing 6, but again the big gains are if you can add caps behind the core.

 

I do not have that problem for now.
Factory Clevo bios is somehow limited to 123W and no settings of MaxwellBiosTweaker can change that.
So 250W is less than what I get with 2x 980m on Prema vBios.

But even that I got graphics score of 12563 point in Fire Strike with memory set to 6Ghz. That is 25% more than 980M.
Anyone knows how to edit Prema bios?

 

I will try squeeze some at the back of the core but it will be hard since the card has a back memory radiator. But I do have some 47uF 100mohs caps 0806 and some 470uf Panasonic GX 3 mOhms SP-CAP's which I used on my 3080TI.
Now I got stable 1202Mhz @1.04V.

 

You can take anything off the back and just have pads going to the motherboard for a better performing solution.