Best PSU for an RTX 4090 and i9-14900K build?

Question

Ive been building rigs for years but this 4090 and 14900K combo is making me second guess my usual math. So I was thinking about just grabbing a 1000W unit because thats always been the gold standard but then I started reading about the transient spikes on the i9 and now Im kinda worried that might be cutting it too close.

My logic was that a 1200W would be overkill but maybe with the new ATX 3.0 standards I should just go big? I need to get this finished by Sunday for an 8K render project here in Chicago and my budget is $300. Is the Seasonic Vertex actually worth the premium or should I just stick with Corsair?

ivmsppnyfg · Accepted Answer

Unfortunately, I have seen too many builders try to skate by with 1000W on these high-end Raptor Lake chips and 4090s, only to face stability issues during heavy renders. I had high hopes for some of the mid-range units lately, but they just arent as good as expected when those massive transient spikes hit. For an 8K project, you really cannot afford a crash mid-way through because of a power trip. Honestly, the Seasonic Vertex is decent but I have personally had better results with the Corsair RM1200x Shift 80 PLUS Gold ATX 3.0. The side-interface makes cable management way safer and the native 12VHPWR support is actually reliable. If you want another option, the Seasonic Vertex GX-1200 1200W 80+ Gold ATX 3.0 is okay, though I have found Corsair ripple suppression slightly more consistent under load. TL;DR: Do not risk 1000W for this combo. Grab a high-quality 1200W ATX 3.0 unit to handle the power spikes safely.

georgiabelmore0 · Answer

You definitely want the extra headroom! That 4090/14900K combo can easily peak way over 1000W in transient bursts. These are fantastic alternatives:

MSI MEG Ai1300P PCIE5 1300W 80 PLUS Platinum - amazing digital monitoring for real-time rail data.

be quiet! Dark Power 13 1200W 80 PLUS Titanium - handles massive excursions like a beast. Go 1200W+ so those Chicago renders dont crash... definitely worth the peace of mind.

jjlrwghjyg · Answer

Bump - same question here