PSU Requirement

[Alias218]

I'm looking to upgrade my PC over two stages, GFX/monitor first, MoBo/CPU/RAM 2nd. The PSU requirement is a sticking point at the mo as different calculators give different results ranging from 300W - 485W peak load using the new hardware (below). Even in it's present form, a 450W 80+ Bronze is too small, apparently, and yet has run fine with this for 4 years. Presently it has:

ATX form MoBo, socket 1150
i5-4670k (not overclocked)
GTX760
2 x DDR3 4GB
SATA 7.2k
DVD W/RW
22" LED 1080p Monitor
Mouse, keyboard, headphones
450W 80+ Bronze

I'm looking to get:

ATX form MoBo, socket 1151
i5-8400
GTX1070ti
2 x DDR4 8GB
Larger 4k monitor (say 28"- 32")
The rest will be carried over (PSU excepted).

What would be a recommended PSU rating for such a setup? 650W 80+ Bronze seems to be the one, but conflicting results don't help my decision making (plus my allegedly inappropriate PSU currently in use throws doubts into the mix).

Thanks.

[8bit]

If the total comes to, say for argument's sake, 500w then the PC won't use that all the time, only when everything is literally going flat out, which basically almost never happens, even running games. If your worst-case requirement was 485w I think you said then I'd just get a 600 or 650w unit from a good quality brand that suits your other requirements (aesthetics if that matters, modular cabling etc.) and not worry any longer over it.

[Bullett]

I'd change the main bits and see if the PSU you have still works ok.

Put an SSD in.
Use the old drive as a media drive.

Is a 1070 going to hack it at 4k? might be ok if you are happy to cut back on quality/framerate.

[born2bslow]

I always go overkill on the PSU it's usually the first thing to blow. I went with a Seasonic 750W, by reputation / on overclockers self build forums they were the preferred brand when I built. PSU problems can fry the rest of the PC so don't cheap out there.

[Lazadude]

I generally calculate max TDP draw and use that as the 70% target of the PSU.

So if theoretical max draw of the system is 350W, then I'd want a 500W PSU. So I'd find the most reasonable 500w by a decent manufacturer that suits my needs, generally fully modular and at that level silent or fan less.

When you get at higher levels, (such as SLI) its worth looking at decent multi rail supplies.

[Alias218]

Thanks for the responses all.

Bullett said:

Is a 1070 going to hack it at 4k? might be ok if you are happy to cut back on quality/framerate.

This is a ti, so a little beefier - in fact according to benchmarks its not a million miles away from a 1080.

Lazadude said:

I generally calculate max TDP draw and use that as the 70% target of the PSU.

Seems like a reasonable rule of thumb, leading to a requirement for a 700W PSU assuming 485W max draw, although the 80 PLUS rating might bring that down a bit.

I'll be honest, I'm not that clued up when it comes to PCs (does it show?) and bought my current rig from Overclockers pre-baked so this is a bit of a curve for me. The last thing I want is to under do it, pop the PSU and take something else out along the way.

I'll go for the over do it route seeing how they're not that expensive and keep digging for my own benefit

[paulwoof]

unfortunately you have just missed a load of deals on prime day

But echoing above, Always over estimate power supply and get a decent one - 80 plus etc

Not only can psu's be the source of problems if things go wrong, They sometimes like to take other expensive components with them when they no longer want to play ball, Was reading about someone the other day on reddit who kept killing 1060's with a dodgy psu thinking it was the gpu the issue.

Also if you every want to overclock things, It will draw more power.

Ive had 2 EVGA power supplys, One is an old 500w 80 plus thats been going strong for near on 7-8 years now, Current 650w has been nearly 2 without issue. Modular too so less cables to faff about with.

[wildoliver]

Can't help massively with your issue but if you want to sell the i5 let me know, I've also got an 1150 mobo running a 3258 and it's recently slowed down and won't play some games following updates. An i5 would probably keep the system limping on for another year or so.

[Alias218]

I did see about Prime Day, but never mind. I still get next day.

I won't be changing the processor for some time, not until next year I shouldn't think. Although if I do sell it, I'll let you know - I don't have the box or protective packaging mind you.

[wildoliver]

Oh I couldn't care less about that, time wise I've been procrastinating for ages already so it's unlikely I'll have done much in the meantime.

[born2bslow]

@Alias if you bought previously from overclockers, get on their forum, there are loads of PC experts who can guide you properly on there. There are other forums but I find it really good for getting PC help, especially on suggestions for upgrades, new parts.

[Lazadude]

Alias218 said:

Seems like a reasonable rule of thumb, leading to a requirement for a 700W PSU assuming 485W max draw, although the 80 PLUS rating might bring that down a bit.

Worth mentioning, the 80 plus rating is rated efficiency at 80% or more for various load levels. Due to the way electrical efficiency works, you start to get diminishing returns above that point and you are more efficient generally below it. Supplies are typically most efficient at between half and three quarters load, much less efficient at low load, and somewhat less efficient at maximum load (which is where my 70% figure comes in).

With a 485W max draw, Id be looking at the best 650 (74% at full load) if you are not looking at upgrading much in the future or 750W (64%) if you may get something with more draw in the future, both fully modular, you can get at your price point.

Quick search on OCUK:

EVGA 650 80+gold - £99
Seasonic "small form factor" 650W 80+ gold - £89

EVGA 750 80+ gold -£124
Corsair silent 750W 80+ platinum - £164

ETA load efficiency stuff

Edited by Lazadude on Thursday 19th July 09:19

[Alias218]

Thanks for the info guys. Very helpful stuff.

[Steven_RW]

1440p monitor with higher refresh rate suits gaming better in most cases.

4k monitors come with lower refresh rate and also put lots of strain on a card.

I'd not run 4k without a 1080ti whereas 1440p on 1070ti (with reasonable overclock) will get much better frames per second and look much smoother.

1440p rarely/never leaves you wishing you had more pixel density.

I run the Alienware 3440 x 1440 ultrawide. It puts lots of strain on my overclocked watercooled 1080. 4k would make even more strain on my card and again, more strain on the 1070ti you suggest.

I would only go your route if I thought I was going to play command and conquer style games rather than high refresh games.

RW

[Alias218]

It's funny you mention that. One of my friends swears by 1440p and another 4K. The 4K friend also insists that 1440p is the more intensive and that you rarely notice the extra frames afforded by the 1440p - basically the opposite to what you have said.

What a nuisance. One thing is certainly true I have found: 4K is more numerous and cheaper, monitor wise.

More food for thought! Thanks for the insight.

[tonyb1968]

If you go totally overkill (add extra fans and storage) then a 750w will be perfectly fine, im still using my Tagan 850w psu on my 1080ti and 5930k eupipped rig and considering the fans and extra hdd/ pcie ssd/ssd/couple of 1-2gb sata 7200's that i run, and the fact my psu is well over 10 years old, it can still handle what's thown at it, and as the more modern cpu's have a lower tdp than mine, you won't need more than that 750w.

[Alias218]

Just to keep you in the loop, I have just ordered:

Samsung U28E590DS monitor - went for 4k over 1440 as I can drop the res down to 1440 with this if things get too taxing, plus at 60hz it's the same as a 1440 @60hz I would have bought anyway - 1440 @144hz is ££££. This is more futureproof than a 1440 @60hz I feel.

Gigabyte GTX1080 - it was £20 more than the GTX1070ti I was looking at so it seemed silly not to.

Seasonic ATX12V 650W 80+ Gold - thanks to Lazadude for the recommendation.


Thanks to all who contributed.

[Lazadude]

Not a problem, happy to help.

If you have any questions/issues building it, feel free to drop me an email.

[Steven_RW]

Alias218 said:

It's funny you mention that. One of my friends swears by 1440p and another 4K. The 4K friend also insists that 1440p is the more intensive and that you rarely notice the extra frames afforded by the 1440p - basically the opposite to what you have said.

What a nuisance. One thing is certainly true I have found: 4K is more numerous and cheaper, monitor wise.

More food for thought! Thanks for the insight.

If you play first person shooters and desire fast reactions, the benefit of higher HZ is bigger than the benefit of more resolution. It helps you smoothly track enemies as you sweep the screen left to right at pace. I went from 60hz 1080p to 120hz 1440x3440.

If you play games like skyrim, or some other game that you control at your own pace, then the benefit of 4k will impress you more.

I'm sure you will like it and see it as positive regardless as 4k will look impressive.

RW

[Alias218]

Lazadude said:

Not a problem, happy to help.

If you have any questions/issues building it, feel free to drop me an email.

Thanks for the offer. I built it up today and it all fired up fine.



Many frames. Much pixels. So wow.

It's very nice though, and a lot quieter than my old GTX760. Maybe I'll lobby for a Vive or Rift for my birthday...

ETA: Behold the potato-like qualities of the iPhone 6 camera.

Edited by Alias218 on Friday 27th July 17:31