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Best PSU for a RTX 4090 build?

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Got it!

I probably should have mention that I'm using a 4K Dell monitor and I'm planning to add a second one on the near future. Would I still be OK with 1000w in that case?

1) Multiple monitors don't influence how much power GPU consumes to big degree. Sure it affects performance, in both desktop and GPU powered applications, but at best it will just raise the idle draw by tiny bit.
2) Desktop monitors don't take any power from PSU, they have their own internal PSU (in majority cases internal), so power goes exclusively from power outlet. That would be different only for portable USB-C monitors that can take upstream both power and data signal (displayport through usb) but even those require their own power source for any reasonable brightness/resolution.

So very much inconsequential :- ) 1000W would be good no matter what in your case.

James Vella:
Theres a few websites around for wattage calculation. This is one.

For your current setup I would say 1000w (as @Juraj mentioned) is enough here is your current setup (i guessed a few things):

If you were to upgrade to 5x 1TB SSD, 160GB RAM (weird number), but then you still are under 1000w:

I didn't even try to calculate anything, with 4090, it's nVidia itself who uses 850W as minimum and 1000W as optimum for Founder's Edition model. This is both for turbo boost (FE edition is 450W by stock, 3rd party use 500W often), but also transient spikes, where even high quality PSUs (particularly Seasonic Focus, very popular range, had issue with this) would aggressively use surge protection and just shut down. With higher watt capacity, transient spikes will use more of PSU's regular capacity before they use peak power.

This is where the new ATX 3.0 PSUs offer benefits as they guarantee 3x Transient for PCIe and 2x for full system. Whether the manufacturers follow this to letter is debatable but it's there.

If this was even more expensive PC, I might be inclined to suggest 1200W, and I would suggest even 1600W for Threadripper/Xeon + 4090W, but in this case the 1000W should be good choice.

Thanks Juraj for all your help! I ended up getting a Corsair RM1000e


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