Is my PSU overkill? Should I go for 550W?

[Andrei1]

PCPartPicker Part List

Type	Item	Price
CPU	AMD Ryzen 7 2700X 3.7 GHz 8-Core Processor	$239.89 @ OutletPC
Motherboard	Asus ROG STRIX X470-F Gaming ATX AM4 Motherboard	$169.89 @ OutletPC
Memory	Kingston HyperX Predator RGB 16 GB (2 x 8 GB) DDR4-3200 Memory	$115.89 @ Amazon
Storage	Samsung 860 Evo 1 TB 2.5" Solid State Drive	$139.99 @ Adorama
Storage	Samsung 970 Evo 1 TB M.2-2280 NVME Solid State Drive	$169.99 @ B&H
Video Card	Sapphire Radeon RX VEGA 56 8 GB PULSE Video Card	$729.89 @ OutletPC
Case	Fractal Design Meshify C ATX Mid Tower Case	$103.19 @ Amazon
Power Supply	SeaSonic PRIME Ultra Platinum 650 W 80+ Platinum Certified Fully Modular ATX Power Supply	$141.99 @ SuperBiiz
Monitor	Samsung LC27JG50QQNZA 27.0" 2560x1440 144 Hz Monitor	$267.99 @ B&H
	Prices include shipping, taxes, rebates, and discounts
	Total (before mail-in rebates)	$2098.71
	Mail-in rebates	-$20.00
	Total	$2078.71
	Generated by PCPartPicker 2019-08-28 05:26 EDT-0400

Is 550W enough if I overclock? And are there any downsides to having more W than needed? Are there downsides to having an overkill PSU?

 

Side Note: The GPU is actually around 300 not 700.

[minibois]

There is no real downside to having a higher wattage PSU (other than paying more, of course). The advantage would be a longer time with the fan OFF and the highest effeciency being at a different point.

What I mean by that, is that the fan on these units seem to turn on at around 40% load, that is of course earlier on a lower Wattage PSU. The highest effeciency point seems to be at around 50%, meaning around 275W vs. 325W is the highest effeciency points on the 550W and 650W units respectively. 

 

But it's not like you need the extra 100W. The Vega 56 seems to use around 240W at load, the 2700X is like 120W overclocked and all other parts don't use a ton of wattage either.

So you could go for a good quality 550W, but if you want to go for a cheaper PSU, you could also go for example for a 'tier lower' 650W like the RM650X.

[Deli]

Vega 56 seems like a bad deal at this price point. Do you have a specific reason to pick this GPU?

 

550w or 650w isn't really a deal breaker, if the price difference is $20. Just buy whatever you want.

[Andrei1]

13 minutes ago, Minibois said:

There is no real downside to having a higher wattage PSU (other than paying more, of course). The advantage would be a longer time with the fan OFF and the highest effeciency being at a different point.

What I mean by that, is that the fan on these units seem to turn on at around 40% load, that is of course earlier on a lower Wattage PSU. The highest effeciency point seems to be at around 50%, meaning around 275W vs. 325W is the highest effeciency points on the 550W and 650W units respectively. 

 

But it's not like you need the extra 100W. The Vega 56 seems to use around 240W at load, the 2700X is like 120W overclocked and all other parts don't use a ton of wattage either.

So you could go for a good quality 550W, but if you want to go for a cheaper PSU, you could also go for example for a 'tier lower' 650W like the RM650X.

So it would actually be better to get a 550W version, since the fans also work at lower load. So even if it's not intensely using the PC the fans might still work, so the temps are being helped more often by the fans.

What do you mean by 'highest efficiency point' ?

Also, can I change when the fans start to work or is it automatic?

[Andrei1]

4 minutes ago, Deli said:

Vega 56 seems like a bad deal at this price point. Do you have a specific reason to pick this GPU?

 

550w or 650w isn't really a deal breaker, if the price difference is $20. Just buy whatever you want.

Sorry forgot to add that the actual price of the Vega 56 is around 300. I've managed to find it for 250. I don't know why it's showing that the price of the GPU is around 700. It's been like this for the past days. The actual price is around 300.

[Deli]

11 minutes ago, Minibois said:

There is no real downside to having a higher wattage PSU (other than paying more, of course). The advantage would be a longer time with the fan OFF and the highest effeciency being at a different point.

What I mean by that, is that the fan on these units seem to turn on at around 40% load, that is of course earlier on a lower Wattage PSU. The highest effeciency point seems to be at around 50%, meaning around 275W vs. 325W is the highest effeciency points on the 550W and 650W units respectively. 

 

But it's not like you need the extra 100W. The Vega 56 seems to use around 240W at load, the 2700X is like 120W overclocked and all other parts don't use a ton of wattage either.

So you could go for a good quality 550W, but if you want to go for a cheaper PSU, you could also go for example for a 'tier lower' 650W like the RM650X.

See many mention the peak efficiency of PSU as a reason for PSU for certain wattage. However the efficiency curve from 20% load all the way to 100% is very flat. The difference from lowest efficiency at 20% load to peak efficiency at 50% load, is like 2-3%. It isn't like that 2-3% will drive up the power bill, or heat up the power supply a lot to make a noticeable difference. It's a bonus if the PC operate at the peak efficiency of the power supply. But it isn't a big deal even if it isn't.

[Deli]

10 minutes ago, Andrei1 said:

So it would actually be better to get a 550W version, since the fans also work at lower load. So even if it's not intensely using the PC the fans might still work, so the temps are being helped more often by the fans.

What do you mean by 'highest efficiency point' ?

Also, can I change when the fans start to work or is it automatic?

You need to look at that specific power supply, if there is a silent mode, or software to monitor and control the PSU's fan.

 

The PSU efficiency is measured at 20%, 50% and 100% load. usually the highest efficiency is achieved at 50% load.

 

If the price difference is small, I'd pick the 650w.

[minibois]

1 minute ago, Andrei1 said:

So it would actually be better to get a 550W version, since the fans also work at lower load. So even if it's not intensely using the PC the fans might still work, so the temps are being helped more often by the fans.

What do you mean by 'highest efficiency point' ?

Also, can I change when the fans start to work or is it automatic?

Efficiency:

A PSU takes power from the wall (115v/230v) and converts that to power your PC components use (12v and some 5v). With any transfer of energy, there is bound to be some current lost. PSU's have a certain efficiency in this process, at a certain % used. With these PSU's, the most efficient point is at 50%:

(With this graph, higher = better)

So what that comes down to, is that this series of PSU is most efficient at 50% load. Not that this should impact your power bill much at all between the 550W and 650W versions.. But it's a difference to mention.

 

The higher wattage PSU's likely use better components that create less heat, thus they have less need to turn the fan on at all times. Looks like this is all automatic though.

4 minutes ago, Deli said:

See many mention the peak efficiency of PSU as a reason for PSU for certain wattage. However the efficiency curve from 20% load all the way to 100% is very flat. The difference from lowest efficiency at 20% load to peak efficiency at 50% load, is like 2-3%. It isn't like that 2-3% will drive up the power bill, or heat up the power supply a lot to make a noticeable difference. It's a bonus if the PC operate at the peak efficiency of the power supply. But it isn't a big deal even if it isn't.

I agree it's not a large differnece, but a different I still need to mention when talking about the different Wattage versions of the same make of PSU's, because as you mentioned it's possible the difference in W can be the difference between falling within the most efficient place of the curve and not.

[Eumel2]

Im just dropping one of these here for you to look at.

This is a Bitfenix whisper m model.

 

If it works out ideally you want your idle power to be above 20% load and you max power lower than 75% to give you a little headroom and also on most units the fans start to ramp up real hard the closer you get to 100% load

 

 

Fan curve for this model:

[Deli]

4 minutes ago, Eumel2 said:

Im just dropping one of these here for you to look at.

This is a Bitfenix whisper m model.

 

If it works out ideally you want your idle power to be above 20% load and you max power lower than 75% to give you a little headroom and also on most units the fans start to ramp up real hard the closer you get to 100% load

 

 

It's a good point. Most people are way overkill for choosing PSU. My system has a 16 core 2950X and 1080Ti. Even if stress tests for both CPU and GPU. It draws about 575w from the wall. I doubt OP's system can draw more than 500w everything max out, more likely in 450w thereabout. A 650w PSU will have plenty of head room. I hope no one will come in and tell OP to get a even bigger PSU.

[Andrei1]

1 minute ago, Deli said:

It's a good point. Most people are way overkill for choosing PSU. My system has a 16 core 2950X and 1080Ti. Even if stress tests for both CPU and GPU. It draws about 575w from the wall. I doubt OP's system can draw more than 500w everything max out, more likely in 450w thereabout. A 650w PSU will have plenty of head room. I hope no one will come in and tell OP to get a even bigger PSU.

Well the price difference is only 20 euros so it's not that big. So I'm gonne see if I go for 550W or 650W. I might keep the 650W maybe will be good for a small future upgrade. For 20 euros I don't wanna 'cheap out' even though the 550W also gets the job done.

Also a noob question, the CPU cooler isn't related to the PSU right? Or is it? Does it start when the CPU is warm enough or something right? Or it has to do with the PSU?

[Deli]

1 minute ago, Andrei1 said:

Well the price difference is only 20 euros so it's not that big. So I'm gonne see if I go for 550W or 650W. I might keep the 650W maybe will be good for a small future upgrade. For 20 euros I don't wanna 'cheap out' even though the 550W also gets the job done.

Also a noob question, the CPU cooler isn't related to the PSU right? Or is it? Does it start when the CPU is warm enough or something right? Or it has to do with the PSU?

The CPU cooler is independent from the PSU.

[Spotty]

Oh, it's this again...
 

29 minutes ago, Eumel2 said:

Spoiler

 

Fan curve for this model:

Spoiler

 

Those are two of the most useless graphs I have ever seen.

The first one has a completely useless axis (10, 20, 50, 100).

The second shows you the voltage of your fan. Who cares about the voltage of their fan!?! It also shows the graph is a scale of "Load (W)" but it only goes up to 100. So at 100W that PSU's fan is drawing 9V running at 1494RPM? I'd hate to have dinner with the person who finds that interesting.

 

55 minutes ago, Minibois said:

The highest effeciency point seems to be at around 50%, meaning around 275W vs. 325W is the highest effeciency points on the 550W and 650W units respectively. 

Can't find the efficiency curves for the new Prime Ultra Platinums, but as an example here's the efficiency graph of the old Prime Platinums from the people who do the 80+ certifications

 

Basically it doesn't matter. If you care about that extra 1% efficiency then buy the Prime Ultra Titanium instead of buying a higher wattage PSU to try and get in the "peak efficiency range".

[Eumel2]

13 minutes ago, Spotty said:

Those are two of the most useless graphs I have ever seen.

The first one has a completely useless axis (10, 20, 50, 100).

The second shows you the voltage of your fan. Who cares about the voltage of their fan!?! It also shows the graph is a scale of "Load (W)" but it only goes up to 100. So at 100W that PSU's fan is drawing 9V running at 1494RPM? I'd hate to have dinner with the person who finds that interesting.

How so?

Load(W) should be Load(%) ill give you that (and wtf Bitfenix, thats a really stupid mistake)