PSU for 2 x RTX2080 (and futureproofing)

[HM-2]

It's currently looking like I might win a second RTX2080 on eBay and I suspect my existing Corsair AX750 Gold probably isn't going to cut it powering a pair of overclocked cards an an overclocked 6900k. I'm also looking at moving to Cascade Lake X (specifically a 10920x) in the fairly imminent future and am fully aware that, when overclocked to ~4.7-5GHz these draw between 500-600w (!) alone so am looking at power supplies that should be relatively "future-proof" for this upgrade.

 

Budget is ~£300 but can possibly push a little higher if required, expecting I'll want something ~1200-1300w.

 

I've not bought a PSU in the best part of a decade but the following seem to represent the relatively limited high-end options in this space:

• Be Quiet! Dark Power Pro 11- seems to lag behind some of the other options in things like ripple suppression and load regulation.
• Corsair AX1200i- I've been a big fan of my AX750 but I don't think I'd actually get much utility out of the "i" functionality. It's also top end of price and expensive per watt.
• Corsair HX1200i- probably a decent "middle ground" between the above and other units, seems to be well reviewed and reasonably priced.
• EVGA SuperNOVA G2/P2- heard mixed things about the quality of these EVGA units.
• Seasonic PRIME Ultra 1200- seem very well reviewed but I don't really have much familiarity with Seasonic other than as an OEM for other brands. Stock availability seems very patchy.
• Silverstone Strider 1300- excessive AC ripple and poor noise suppression.

The Corsair units and Seasonic initially look like the best options to me but I have no idea if the AXi offers significant benefit over the HXi, or whether the Seasonic is worth waiting for someone to get stock of; any recommendations or other suggestions greatly appreciated

[Antistatic12]

Have you double checked on a online PSU calculator to get a reasonable expectation of the wattage?
My vote goes towards the Corsair AX1200i, Had it for years and never skipped a beat.
Keep in mind the higher end Corsair PSU's are made by Seasonic/Flextronics.
So realistically the Seasonic you listed would be a good option as well.

Spoiler

Corsair - from Whirlpool forums.
AX-650 – Seasonic
AX-750 – Seasonic
AX-760 – Seasonic
AX-760i – Flextronics
AX-850 – Seasonic
AX-860 – Seasonic
AX-860i – Flextronics
AX-1200 – Flextronics
AX-1200i – Flextronics

CX-400 – Seasonic
CX-430 – Channel Well(CWT)
CX-430 v2 – Channel Well(CWT)
CX-500 – Channel Well(CWT)
CX-500 v2 – Channel Well(CWT)
CX-600 – Channel Well(CWT)
CX-600 v2 – Channel Well(CWT)

Gaming Series GS600 – Channel Well(CWT)
Gaming Series GS700 – Channel Well(CWT)
Gaming Series GS800 – Channel Well(CWT)

HX-450 – Seasonic
HX-520 – Seasonic
HX-620 – Seasonic
HX-650 – Seasonic
HX-750 – Channel Well (CWT) (DSG platform)
HX-850 – Channel Well (CWT) (DSG platform)
HX-1000 – Channel Well (CWT)
HX-1050 – Channel Well (CWT)

TX-550M – Channel Well (CWT)
TX-650 – Seasonic
TX-650 v2 – Seasonic
TX-650M – Channel Well (CWT)
TX-750 – Channel Well (CWT) (PSH(older) platform)
TX-750 v2 – Seasonic
TX-750M – Channel Well (CWT)
TX-850 – Channel Well (CWT) (PSH(older) platform)
TX-850 v2 – Seasonic
TX-850M – Channel Well (CWT)
TX-950 – Channel Well (CWT) (DSG platform)

VX-450 – Seasonic
VX-550 – Channel Well (CWT) (PSH platform)

 

[HM-2]

The online calculators point to circa 1200w minimum with finger in the air CPU voltages.

[Haro]

1 minute ago, HM-2 said:

The online calculators point to circa 1200w minimum with finger in the air CPU voltages.

Why do you need sli / NVlink ? 

It doesn't give you performance gains in games and it will cause scalability problems

Unless you need it for something else 

[HM-2]

1 hour ago, TofuHaroto said:

Why do you need sli / NVlink ? 

I don't particularly, I just fancy trying it out again. I'm fully aware support is patchy and scaling in some applications nonexistent or even actively detrimental. Though it's far from true to say it doesn't add performance at all.