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To show just how MSI’s twin 12V-2x6 connector design helps maintain stability and reliability under extreme loads, we examined the temperatures of the dual 12V-2x6 cables compared to the single connector of the RTX 5090 Founders Edition under load using our thermal camera. We chose Alan Wake II with path tracing enabled as our test load for this analysis, since that title had the highest power draw in our game tests.
Even on an open bench and with active cooling pointed at the power connector, the RTX 5090 Founders Edition’s 12V-2x6 cable reaches 58 °C.
Under the most extreme gaming workload we have, spreading power delivery across two 12V-2x6 connectors greatly reduces the temperature of each cable— to between 46 °C and 47 °C, or by more than 10 °C compared to a single-connector card.
Just for kicks, we also fired up FurMark with our manual overclock in play. Under this extreme synthetic load, the Lightning Z hits its full 1000W TGP with its Extreme vBIOS, and our test system is pulling over 1200W from the wall.
Even with this insane amount of current moving through its power cables, the dual-connector design of the Lightning Z means that neither cable gets worryingly hot. Both cables stabilized at about 52 °C.
Our test data demonstrates that the RTX 5090 Founders Edition usually operates at power levels far lower than its 575W TGP while gaming, but not always. If you enable path tracing in games that support it, power draw greatly increases, and overclocking increases it further still.
The fact that it’s even possible to produce such high temperatures on the cable and connector within stock operating parameters and with active cooling remains an indictment of the power delivery design of the Founders Edition 5090 – and, by extension, most partner card designs.
Including two 12V-2x6 connectors on every 5090 would certainly have increased costs and complexity for DIY builders, PSU makers, board partners, and system integrators alike, but a design that’s harder to push to its design limits could and likely would have avoided costly meltdowns, risk to property, and endless bad PR.
All this is wishful thinking in a market where Nvidia can clearly sell every RTX 5090 it makes regardless of the risk of a power connector failure, but it’s worth remembering that melting plugs were practically unheard of before the introduction of the 12VHPWR connector, and we think that as the market leader and ecosystem driver in graphics cards, Nvidia should cultivate a stronger safety culture for future designs. The benefits of an alternative approach are staring us right in the face.
Bottom line
The MSI RTX 5090 Lightning Z unleashes Nvidia’s most powerful gaming GPU like no other card before it. Its dual 12V-2x6 connectors, extreme power delivery subsystem, and exotic cooling design let you explore the full potential of the GB202 chip with absolute confidence in its safety and stability.
All of that extra power delivery and cooling headroom translates to about 12% better performance than the RTX 5090 Founders Edition in our tests. Manual overclocking extends that lead to an incredible 18% (though overclocking the 5090 FE in turn narrows that back to 10%).
In the recent past, that kind of performance increase would have prompted Nvidia to release an RTX 5090 Ti. But unless or until it does, this Lightning Z card provides a durable performance advantage—and bragging rights—over lesser RTX 5090s with a single power connector.
And that particular, exclusive satisfaction is why this card is an eye-popping $5090. If you’re putting down this much money for a graphics card, you want it to be more than just a product. You want it to be a spectacle, an occasion, a conversation piece that can be enjoyed and then displayed long after new generations of graphics cards eclipse it. The RTX 5090 Lightning Z is certainly that special, from its packaging to its build quality and industrial design to its performance results and overclocking experience.
Beyond its unique technical distinctions, the Lightning Z is one of the coolest-looking and best-built graphics cards I’ve ever had the privilege of using. The huge LCD screen on the face of the card begs for a vertical mount in a build, and MSI’s included bracket and riser cable let you do that with ease.
It barely rises to the level of a complaint, but our power measurements suggest the Lightning Z’s Extreme vBIOS and its 1000W TGP are really meant for extreme overclockers for whom the stock cooler is just an obstacle to mounting an LN2 pot. Even the most demanding gaming workloads just don’t push the card hard enough to use all the extra power headroom afforded by the Extreme vBIOS, whether stock or overclocked.
Even with its extraordinarily high price and any retailer markups that might get stacked on top, MSI will certainly sell every last one of the 1300 Lightning Zs it plans to release, both to well-heeled enthusiasts and to extreme overclockers with dewars of cryo-coolant at the ready to chase the #1 spots on the HWBOT leaderboards. Our verdict, then, is largely ceremonial.
As a merely mortal PC gamer and enthusiast of modest means, I can tell you that the Lightning Z advances the state of the art for RTX 5090 board design by every measure at our disposal, and I’m glad MSI’s designers and engineers got the opportunity to go wild to make it happen.
If you evaluate purchases with the objectivity of Commander Data and just want a graphics card to plug in and game with, any other RTX 5090 will do. But if you demand the absolute best RTX 5090 yet made, I’m confident in saying that this is it.
