Seasonic 750W vs 850W

[soundhunter]

Hi everyone.
I need an advice on psu.
I'm choosing between Seasonic Prime Ultra Platinum 750W and Seasonic PRIME Platinum 850W. The calculator shows that I need 606w. So 750 should be enough, but maybe I'm missing something?
Also, what's your opinion on those two models?

specs
asus tuf x299
i7-7800x
gtx 980ti (will switch to rtx 3080 or 3080ti)
m.2 samsung 1tb 970 evo + 2tb 970 evo plus
32Gb DDR4 3600MHz G.Skill Sniper X
and air cooling: 2 fractal fans 120 + noctua 140

 

[Mr.Scott]

They are both high end PSU's. 750w is more than enough for your rig, so buy which ever is cheaper.

 

[Dr_Emmett_Brown]

The calculator shows that I need 606w. So 750 should be enough, but maybe I'm missing something?
Also, what's your opinion on those two models?

In general, the closer your ACTUAL power draw is the maximum rating of your PSU, the more likely the signal-to-noise ratio will degrade. Ever get random restarts,the ole blue screen of death, and other things that all seem different but all cause crashes? Well if it's not a component suffering from electrostatic discharge damage, most likely it's the PSU no delivering a clean, smooth sinusoidal signal.

I always overdo it when it comes to the PSU.

My own personal preference is CORSAIR and my most recent build I went with a 1200 Watt powerhouse.

But don't let my caveats scare you. To be safe, I'd go with an 850 Watt PSU, just in case you add any components later than would otherwise push you too close to the limit.

 

[Zerileous]

In general, the closer your ACTUAL power draw is the maximum rating of your PSU, the more likely the signal-to-noise ratio will degrade. Ever get random restarts,the ole blue screen of death, and other things that all seem different but all cause crashes? Well if it's not a component suffering from electrostatic discharge damage, most likely it's the PSU no delivering a clean, smooth sinusoidal signal.

I always overdo it when it comes to the PSU.

My own personal preference is CORSAIR and my most recent build I went with a 1200 Watt powerhouse.

But don't let my caveats scare you. To be safe, I'd go with an 850 Watt PSU, just in case you add any components later than would otherwise push you too close to the limit.

While that logic was sound in the past, especially with PSUs sold with inaccurate and dishonest power ratings, modern PSUs from high quality and reputable manufacturers (such a the Seasonic Prime and a few others) will easily maintain their rated output all day long, all while maintaining class leading ripple suppression and voltage targets.

There is absolutely no need to go for an 850W PSU. And yes I would always take a higher quality unit rated to run at the needed capacity of the system then a lower quality unit with extra wattage headroom.

 

[Robert17]

Remember also that newer components being developed by the various manufacturers are targeting lower power/higher performance goals. So you may need less rather than more power in the future.

 

[Blaylock]

While that logic was sound in the past, especially with PSUs sold with inaccurate and dishonest power ratings, modern PSUs from high quality and reputable manufacturers (such a the Seasonic Prime and a few others) will easily maintain their rated output all day long, all while maintaining class leading ripple suppression and voltage targets.

There is absolutely no need to go for an 850W PSU. And yes I would always take a higher quality unit rated to run at the needed capacity of the system then a lower quality unit with extra wattage headroom.

I came here to say the same thing. So I'll add some references instead, Oklahoma Wolf's in-depth review of each.

Seasonic Prime Platinum 850W - Grade = 9.3 out of 10

Seasonic Prime Ultra 1000W Platinum - Grade = 9.2 out of 10

Note: I know this isn't the 750W PSU but this is for quality comparison between models. Keep in mind Price and Value are a factor in these reviews so if a sale comes up, so does it's value.

 

[EarthDog]

Great psus.... the 750W will be plenty. I rock a 7960x (4.5ghz all c/t) and 2080ti without worry. You'll be fine with 3080ti amd that cpu.

I so wouldnt worry about running too close to capacity and snr. That calculator is on the high side and at MAXIMUM (stress tests) you wont see 600w in the first place.

 

[soundhunter]

Thanks everyone!
I was thinking of 850w one because It gives more space for upgrades. For example I forgot to add another 32gb ram(going to buy soon). And only with that, calculator shows that I need 770w psu. What if it's a new cpu? I understand that it's on a high side but still, won't 750 be a potential bottleneck in my case?
Also the price is almost the same.

 

[EarthDog]

RAM will only be a few/several watts... RAM doesn't use 170W, that is insane.

Again, you already have a fairly high-end power-hungry CPU and GPU. IF you are stress testing both the GPU and CPU at the same time, overclocked, you likely won't break 650W. During normal activities like gaming and such, you won't break 500W. You have plenty of headroom for new parts or overclocking.

 

[SPL Tech]

most likely it's the PSU no delivering a clean, smooth sinusoidal signal.

PSUs output DC, not AC. They output 12, 5 and 3.3VDC. Virtually no electronic device uses AC. Very few. Almost anything running into a circuit board is going to be running off DC.