Shunt Short Hardmod to completly disable throttling on Nvidia 900m series (M17x R4 and M18x R2 SLI)

Hi Guys!

Been meaning to post this for a while, like others I've have had problems with incurable throttling with the 980m in M17x R4, Ranger 17 and even worse in the M18x R2 SLI. Worse on the 18 where you get stuck in the P1 profile.

Only concrete solution I've come up with is to short the shunt resistor on the card. This component has a very low resistance (a few milliohms) and the card measures the voltage drop across it to work out how much current the card is drawing. Solder a short piece of wire across it (or better yet remove altogether and flood the pads with solder) will make the vbios and ec think the card is drawing near to 0% power consumption at all times and stick at full performance.

Warning!

1. Do at your own risk, soldering is not for everyone.
2. Its my belief there are different revisions of 980m pcb out there (Ive personally tested two identical looking cards with the same vbios in the same laptop, one will throttle the other will not).
3. This mod has been tested with the M17x R4 and M18x R2 SLI.
4. If with M18x R2 you are always in P1 state, this mod will make card run at full clocks but you'll still need a vbios that matches the memory clocks of P0 (or manually set via software) for full performance.
5. further warning! card will now have virtually unlimited power target, make sure you have adequate (probably 330w charger) to cope.
6. This wont work with the pascal cards, they have additional protection that locks the clock speeds low if they detect shunt short, but soldering an equal value shunt in parallel with stock one may work and give readings of 50% (ie 200% power target).

Oh and lastly thanks to my mate Darren who's not on the forum but was crazy enough to let me near his sli set up with a soldering iron

Javers

 

Nice, but really the missing VRMs should be added before using this, the standard 980M config was already too close to the edge of its stock power draw.

 

Wow does the 980M normally get 12.6k firestrike? That is almost the same as the 1070M

 

It's SLI, and yes 2x 980Ms are almost a 1070M... when sli works really well, firestrike is like the best case scenario for it.

Also, look at gpu score only when comparing GPUs, overall score is affected by cpu which in this case is a sandy bridge quad. The 980Ms in my P870DM which had a lower gpu score than here would get about 14.6K overall because of the 6700K @ 4.6ghz

 

Yeah only GPU score matters.

@javers How bout SLI power draw, would 1x 330w adapter be still enough then?

 

What driver version are you running?

On my MSI 980m I can't change my voltage when I overclock, I'm already running a modded VBIOS and I could up the voltage with afterburner, but at least since January that is not possible anymore, any voltage that I put in Afterburner is just ignored..

 

How do you identify which resistors control how much power the card pulls? For example I got a RTX 2070 mobile, I've checked the tech manual but still can't figure it out. Is there a specific number next to it or something else that helps me identify it?