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To judge what the RTX 5090 Lightning Z can do, we ran it through a subset of our larger game testing suite at 4K ultra settings.
Gaming performance
Gaming power draw
We started our performance testing with Stalker 2 and Marvel’s Spider-Man 2, but as you can see from the accompanying PCAT power charts for each game, even those titles just weren’t working the Lightning Z hard enough to really exercise its expanded power limits.
To really push the card, we had to enable path tracing in several games that support it: Doom: The Dark Ages, Indiana Jones and the Great Circle, Black Myth Wukong, Alan Wake II, and Cyberpunk 2077.
You can see from those per-game power charts that enabling path tracing alongside DLAA and frame generation can drastically increase gaming power draw over raster or lighter RT settings, anywhere from about 50W to 100W on average.
Those results clearly demonstrate the advantages of the Lightning Z’s twin power connectors and greatly expanded power limits versus the Founders Edition. Nvidia’s GPU Boost algorithm will happily take advantage of the added headroom, and our manual overclock is able to extract even more performance.
All told, the RTX 5090 Lightning Z is 12% faster than the RTX 5090 Founders Edition out of the box, and our manual overclock expands that lead to an incredible 18%. In the recent past, a performance increase this large might have prompted Nvidia to release an entire new family of RTX 5090 Ti cards. Clearly, the GB202 chip still has headroom in it.
But the extreme power and cooling required to realize that performance increase has considerable knock-on effects for system design and component choices, and between the lack of high-end competition and the difficulties of taming such a high TDP likely make Nvidia reluctant to fire off an 800W RTX 5090 Ti as a product for general audiences.
To be sure, you can narrow the Lightning Z’s lead back to 10% by overclocking the Founders Edition in turn, but then you’re further stressing the single 12V-2x6 connector of that card. The RTX 5090 Lightning Z lets us push the GB202 GPU to the max, and it lets us do so with absolute confidence in its stability and operating limits.
