Which PSU wattage for new build (i7-6700K, GTX970)?

[Timo]

For my former build (Gigabyte GA-P35-DS4, Core2 Q9450 2.67GHz quad, 4GB DDR2) I used a Corsair HX520 PSU and was impressed by its build quality, stability (been using it every day since 2008) and modularity, and wanted to opt again for a Corsair PSU for a new build.

Looking at the following build:

• Asus Z170-A motherboard
• Core-i7 skylake 6700K 4.0GHz quad, with Noctua NH-U14S CPU fan (air cooling)
• 16GB (2x8GB) Corsair DDR4 Vengeance LPX Black, 3000MHz, CAS 15-17-17-35, 1.35V
• 4GB MSI nVidia GeForce GTX 970 graphics
• 3 or 4x SATA 7200RPM internal hard-drives
• Texas Instruments Firewire PCIe board with bus power (to power an external Motu Traveler firewire soundcard)
• Samsung DVD-RW/BluRay
• Floppy drive (yep, I still use floppy disks for external studio equipment)
• 3 standard case fans (no radiators nor liquid cooling)
• Windows 8.1/10

Extra details:

• The computer will mostly be used for:

1. high-performance, very low-latency audio production
2. 3D rendering (3Ds Max)
3. casual gaming

• I may have the CPU professionally overclocked to 4.6GHz by 3XS - but if doing so necessitates liquid cooling, I'll most likely leave it at stock 4.0GHz and stick to using standard air cooling instead.
• I will never install a graphics card more powerful than the GTX 970 for the lifetime of this machine, I'm merely a casual gamer and the GTX 970 is already more than I'd ever need.
• I will never need nor use two graphics cards (SLI/Crossfire).
• The only thing I may add in future is an SSD harddrive.

Given the above, which wattage should I be looking for in a PSU for this build?

Many thanks,
Timo

[gupsterg]

Hi,

Have you tried this? Link:- http://outervision.com/power-supply-calculator

[Timo]

Ah, thank you, seems the build with internal and external hardware, overclockings, and adding an extra buffer would draw under 600W at absolute full tilt, so would a 750W PSU or thereabouts appear sensible?

Looking at the Corsair HX750i

[gupsterg]

I reckon you can go lower.

That calculator is known to go a little over kill , so you already have a buffer .

Bit Tech review of i7 6700K, under heading Power Consumption have a read .

They were not loading up the GPU (they had a 390 in the setup) you can see even when OC'd to 4.8GHz their bench setup is pulling 197W at power meter on wall socket, standard 970 specs state 145w as max for card; so you could say 197W+145W=342W.

The kind of power P95 small ffts pulls through a CPU in general use / gaming you never gonna see that being pulled IMO (from tests I've done on my systems, still exc.GPU load).

I'd say a decent 500W is gonna be ample, only time I'd get a bigger PSU is if it's working out similar / price efficient. For example the CoolerMaster V650 was £61 inc VAT/P&P at the time of purchase and a 550W version was £70 odd IIRC.

Here is a Bit Tech roundup of some GTX 970s, these power figures are for the GPU under load and is their whole bench systems power use. Check out the test setup page plus read each cards specs as any pre'OC'd ones will pull more power than non OC'd (again consult graph on power page).

*** edit ***

CCL have the CM V650 Semi modular for £67 inc VAT shipping, OEM is Enhance for that PSU, check out review on TechPowerup for V550.

[Greybeard]

Ah, thank you, seems the build with internal and external hardware, overclockings, and adding an extra buffer would draw under 600W at absolute full tilt, so would a 750W PSU or thereabouts appear sensible?

Looking at the Corsair HX750i

For that spec you provided, a 600w power supply is definitely more than adequate for the system. I'd would go for a 750w range like that HX750i you mentioned, if you are looking forward to add another 970 in the future, then the 750w would make a lot of sense.