So for someone who might me interested, back when 980m SLI was a thing for the M18x R2, power was not enough. So I went ahead and made my own dual power supply mod with a coulomb meter that shows wattage, Voltage, amperage and power consumption in real time.
Recipe was simple. Two power bricks, a bridge rectifier to direct voltage and amperage in one direction, and a screen to show me what is happening.
So I picked up:
- An coulomb meter and a shunt to withstand at least 50amps
Because 330w / 19,5V = 17 amps x 2 (psus) = 34 amps
- 4 Diodes with the lowest voltage drop
- Two Dell specific Cable Extensions (that was the name on Ebay)
- Cable fasteners with adhesive tape
- Insulating tape
- Soldering Iron
- My trusted dremel
- Patience and 'Vision'
So the idea was to have it modular, so both psus can be connected at the same time, or just one, or none.
Also to prevent throttling
- Flash swicks unlocked A11 Bios to be able to use 980m obviously
- Power up the system
- Enter BIOS setting
- Go to Advanced Settings and Video Configutation
- Select IGFX (intergrated GPU)
- Save and Reboot
- Enter BIOS again, no need to wait to enter windows
- Switch your GPU to Dedicated one (PEG).
This is effective as long as you keep your laptop to the wall charger and even when putting it to sleep. If you power it down, and plug it back in, repeat the process.
Actual footage of both GPUs running at 97%
Here is the screen
The 'finished' product!
The cable fasteners
Wiring instructions
Diodes
My second 980m has long gone, so I am only running single, and with the family and kids, I bearly use my laptop. I am at a search for a 980m just for the 'fun' of it.
It is always 'cool' to have a dual GPU laptop 😅😅😅😅