The Thermaltake GF3 model with 750 W max power is a fully ATX v3.0 and PCIe 5.0 compatible PSU, meaning that you won't have to use 12VHPWR adapters to power your precious graphics card. Recently, there were some issues with NVIDIA's adapter with melted connectors and sockets, which worried many users. The fact is, for power levels during gaming, the RTX 4090 can reach close to 500 W power consumption, so I don't suggest the use of adapters. From the moment you invest so much money to get a high-end GPU, you should put some money aside and also get a PSU with a native 12VHPWR connector, or order a native cable for your PSU, if there is one available. I know that be quiet!, Corsair and Seasonic offer such cables for their non-ATX v3.0 units, and other brands are also working on releasing such cables.

The GF3 750 offers high-enough performance and quiet operation. Moreover, it successfully passed all ATX v3.0 transient response tests so that it won't have a problem with power spikes. However, I didn't measure any notable power spikes with flagship GPUs, even with the most affordable RTX 4090, the Palit GameRock OC, at overclocked speeds, asking a lot of VRMs. The only thing that needs attention in this PSU is the 600 W 12VHPWR connector, since Thermaltake grounded both Sense 0/1 pins. According to the ATX guidelines, a 750 W PSU should come with a 300 W 12VHPWR connector. Still, it is a significant pain for all brands to offer different cables according to the PSU model, so Thermaltake chose to only have a single 12VHPWR cable at the max rating of 600 W. The worst thing to happen is to have restarts, although a good 750 W PSU can handle an RTX 4090 and a powerful CPU at stock speeds.

Two notable opponents for the GF3 750 are the Corsair RM750x, which remains the performance king of my charts in this category, and the Cooler Master V750 Gold V2. Nevertheless, neither Corsair nor Cooler Master has yet updated the models mentioned above with 12VHPWR connectors, which I expect to happen soon.