Worth investing in excellent power supply instead of very good power supply?

Zaporro

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Jan 23, 2014
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So I'm having a dilemma that lingers for a while already and I'm still bouncing back and forth between two options.
Its intended use is 1440p gaming with GTX1080ti and i7-8700k (casual overclocking, nothing extreme as 5GHz etc.)

Its 'excellent' power supply vs 'very good' power supply and i can't decide which should i pick.

Here is timeline of my thoughts:

- OuterVision calculator shows approx 550W power usage of my build (but its based on current i7-7700k with voltage OC to 1.3v)
- I plan to buy Seasonic Prime Gold 650W
- 50/50 people online say 650W will be enough since its very good quality while other people say go for 750W because PSU are most efficent at lower load and there will be less noice
- people say i7-8700k might draw significantly more power than i7-7700k
- I plan to buy Seasonic Prime Gold/Platinum 750W (they are at same price where i live lmao, either Gold 750 is overpriced AF or its good deal on Platinum)
- Price leaks of i7-8700k
- Price leaks of Z370 motherboards
while()
{
- My budget shrinks
- Starts thinking again if should buy Prime Gold 650W
- Gets doubts about power usage again
- Thinks if i should buy instead lower class PSU
- Decides to buy Seasonic Focus Plus Gold 650W
- Remembers about power usage
- Maybe Seasonic Focus Plus Gold 750W
- Thinks that PSU is most vital component of PC and should be choosen appropriately
- Back to Seasonic Prime Gold/Platinum 750W
}
//infinite loop
//Help Me Tom's Hardware, your my only hope!

What do you think?
First question, should i really go for 750W? For me, a little fan noise is not problem, but i do care about well being of PSU. Projected 550W/650W = 85% top load vs 550W/750W=73% - will it make any difference?

Second question, is it really worth it investing in such top tier PSU (Prime series instead of Focus Plus) at low wattage?

Will such top tier really be valid for long term use (with price like that i expect at least 5 years but then, during 5 years everything can happen like new ATX standard, new power modes that wont be supported by old PSU /cough Hasswell ready mess cough/)?

Im already kind of 300$ below planned budget. As far as the prices go:
Focus Plus Gold 650 < Prime Gold 650 = Focus Plus Gold 750 < Prime Gold 750 = Prime Gold 750.
For comparision, Corsair RM650x and RM750x both cost same and they are pricewise the are minimally more expensive than Prime Gold 650W.
 
Note that power supply calculators already overestimate the needs, to make sure nobody actually gets PSU that is too weak for them. But to answer your question, assuming 8700 will not consume much more power them 7700 when OC-ed (which we can't determine now), 650 W will suffice for your build. So, each of PSUs you listed will work for you (and all are great units). I would stick to 650 W unit, and would take Prime Gold or Corsair RMx if I had the money, Focus Plus otherwise.
 

Zaporro

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Jan 23, 2014
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thanks for insight, for the prices I'm using my local prices and converting them from PLN to USD, they will be higher than US prices by 25% due to taxes
 

ashtontawtis

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Sep 14, 2017
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Hey Zaporro,

For the powering of your build, i suggest getting a 650W+ variant. Getting a higher wattage PSU helps to future-proof your system, although I don't think you will need to upgrade for a while. It also decreases the load on your power supply, making it's work easier, and generally giving it a lesser chance of malfunctioning, which I don't think you will want in your build. 650W should suffice for your setup, but it depends on whether you would rather spend more money now, or later. For a brand, Corsair make excellent units with a great reputation amongst the PC community.

Hope this helps
 
Hmm, Poland huh?
I can give you a list of good psu :
Corsair rmx, txm
Evga g2/g3/gq
Seasonic all gold rated are excellent
Xfx pro series, xtr
Thermaltake toughpower grand series (try for the dps g or pro rgb)
Super flower gold rated psu
Fsp hydro x/g
Enermax revolution x't

Or if the queer ones like the chieftec is available, go for the 8000 series as its the same as toughpower grand.
 

Zaporro

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Jan 23, 2014
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10,710




Thanks, yeah ive seen it, its price is about as Seasonic Focus Plus 750. As for RM750x and RM750i they are also priced in similar way. I heard that from these two the "i" version has better insides but i dont know how they both compare to Seasonic Focus Plus Gold 750.