Introduction

I want to thank Seasonic for lending me the RTX 4090 for this article.


After hearing lots of debates about whether the sense pins on the 12+4 pin connector actually affect the RTX 4090's performance, I decided to find one of these cards and check what's going on. Thanks to Seasonic and MIFCOM, I found a Palit GeForce RTX 4090 GameRock, the standard not the OC model, which is among the most affordable RTX 4090 on the market. I know its VRMs are not as strong as in high-end RTX 4090 models, but for this article, it would be fine. Actually, the three legacy PCIe to a single 12VHPWR connector, rated at 450 W, that this card is shipped with will help me make a direct comparison with a native 600 W 12VHPWR connector.

I first completed a full set of tests with a previous generation Seasonic Prime Titanium 1000 W PSU using the provided 12VHPWR adapter. I didn't have any issues, so NVIDIA's claims that the RTX 4090 doesn't require an ATX v3.0 PSU stand up to testing. Even under overclocked conditions, the 1000 W PSU was fine. For detailed power consumption readings, I am using a Powenetics V2 system, which offers more than 1000 readings per second (>1000 Hz polling rate) on 13 sensors so that it can catch every nasty power spike. A significant asset of Powenetics is that besides the GPU, it also monitors at the same time the system's total power consumption, including the CPU's, so I have a clear image of what is going on.

Since the Palit RTX 4090 GameRock that I received had a power limit of 450 W, and I needed a higher one to see if a 600 W rated 12VHPWR connector (Sense 0 and 1 grounded) would provide any gains, I decided to flash it with the GameRock OC model's BIOS, which I found in TechPowerUp's database. Using a non-public NVFlash version, things went smoothly, and finally the power limit increased to 500 W, which is appropriate for this card's VRMs.