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PSU For RTX 4090

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Jul 1, 2019
My PSU died on me so I need to replace it now. I currently have a Corsair CX600 driving a PC I built back in 2017 with a GTX 1070 TI GPU. My plan is to rebuild early next year with an RTX 4090 GPU. I am not a big overclocker.

I'm not sure what my best options are for under $200. I see an "ASUS ROG STRIX 850W Gold PSU (‎ROG-STRIX-850G)" on Amazon right now for $115, which has a list price of $180.

Is that a good choice or is there something else I should be looking at? I did see some comments about people waiting for ATX-3. Should I get something cheap now to tide me over until the new standard hits?

Appreciate any help!!!
850W Gold 80+ units should be good enough. I don't know who is the OEM for ASUS PSUs, but every known brand Gold/Platinum 80+ is good nowadays.
I know that RTX4090 works on quality/high-efficiency 750W PSUs too, and EarthDog was using 850W in his reviews.
Most, if not all RTX4080/4090 cards have a 3x8pin to 12/16 PCIe 5.0 adapter included. It's recommended to plug every 8-pin into a separate cable (if a cable has 2x8-pin, then use only one). So the best would be a PSU with 3x single 8-pin connectors or 3x double 8-pin (6x 8-pin in total). The mentioned ASUS Strix PSU has 6x 8-pin on 3 cables, so will be just right.
I would second the recommendation to have each 8-Pin for the GPU on a separate line from the PSU.

80+ Gold or Platinum from brands like Corsair, EVGA, or Seasonic would be my recommendation. If I have a $2,000 GPU, I'm not trying to save $30-50 on the PSU. So I would be very selective with my manufacturers.

850W should likely be OK with your current CPU, but if you go DDR5 you might be bordering on 1000W territory. A fully boosted/overclocked 13th Gen i9 + 4090 could potentially pull closer to 900W (I'm seeing articles citing 250W+ on the i9, as well as 4090 hitting almost 600W in Furmark), so the headroom of a 1000W unit might not be a bad idea.
850W should likely be OK with your current CPU, but if you go DDR5 you might be bordering on 1000W territory.
My 850W PSU with 13900K and 4090 are livin' the life together. I upgraded from 750W. ;)

Granted I don't do stuff like force feed a power virus (furmark) to my GPU and run a stress test against my CPU at the same time... lol