RTX 4090 laptop shunt modded: 19% more performance, near RTX 5090 laptop perf for half the cost

A Redditor has shunt modded his RTX 4090 gaming laptop and unlocked 19% more performance, bringing its performance closer to a much more expensive RTX 5090 gaming laptop.

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In a new post on Reddit, "u/thatavidreadertrue" shunt modded the GeForce RTX 4090 Laptop GPU inside of his ASUS Zephyrus M16 GU604VY gaming laptop, stacking a 1m Ohm resistor on top of the existing 5m Ohm resistor, lowering the resistance to around 0.83m Ohm. This tricked the laptop GPU into thinking it was consuming 6x less power, which is why the power draw reading displayed 40-45W, compared to its actual power draw of closer to 240W, which is 1.6x more power than the reading.

Increased power always means more heat being generated, with the user repasting the old liquid metal on the GPU using Honeywell PTM 7950, a phase-change thermal interface material (TIM) which is known for excellent performance. The user also upgraded the VRM thermal pads with the Upisren UX Pro Ultra.

• Read more: This shunt-modded air-cooled RTX 5090 smashes 3DMark records, unlocks huge 1200W TDP
• Read more: NVIDIA RTX 5090 laptop GPU is 'shunt modded' to make it 20-30% faster in games

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The performance benefits are pretty damn good, with the shunt modded RTX 4090 averaging 19.2% additional performance in multiple 3DMark benchmarks compared to stock, and also 3.5% more performance over an average RTX 5090 gaming laptop. They're some damn good results, that's for sure.

The Redditor explained: "I shunt modded a Zephyrus M16 4090 GU604VY to have a thin and light laptop that has the performance equal to 5090 laptops without paying a crazy premium ($1600 for the M16 vs $3500+ for 5090s with similar form factor). There are other shunt modded 4090 laptops, but they are thick desktop replacements, and I wanted a laptop that I could still easily travel with. The M16 is a good candidate for a shunt mod because despite being a thin and light, it is designed with enough power phases and cooling to handle a 150W TDP GPU + a power hungry CPU, especially once you repaste it".

The poster continued: "The laptop was shunt modded by stacking a 1mOhm resistor on top of the 5mOhm shunt resistor at the back of the motherboard. Any power readings will be 6 times lower than the actual power draw. I also repasted the old paste/liquid metal on the CPU/GPU with PTM 7950 and replaced the VRM thermal putty with better aftermarket putty (Upsiren UX Pro Ultra)".

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The poster concluded: "If you can take the risk, shunt modding a 4090 laptop can get you performance matching or better than a majority of 5090 laptops for 1/2 the price. Shunt modding a thin and light laptop can get almost as good a result as desktop replacements while still having good portability".