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Question Undecided on my PSU

Aug 8, 2019
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CPU : Ryzen 5 3600
GPU : RX 570 4gb
MOB : MSI B450M Mortar max
MEM : g skill ripjaws 2x 8gb 3200C16
SSD : ADATA SU500gb Sata
PSU : ?
Monitor : ViewSonic VX2458
Case : Thermaltake H18

Hi guys i am building my first pc and I still havent decided on what psu to get. I want to get the cheapest one that also has good quality..
 

extreme_noob

Notable
Jul 30, 2018
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Well for the most part you either have a good psu or a cheap one. You cant have both.
For quality, corsair rmx or evga gq/g2/g3 are all high quality.
As for wattage, you can go to a psu wattage calculator, or make a list on pcpartpicker, but make sure to have just a bit more wattage than the estimate
 

AllanGH

Estimable
Mar 10, 2019
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...make sure to have just a bit more wattage than the estimate
It's not "just a bit more" that you need to shoot for.

Power supplies age, and they also have to contend with expanded demands over time. They also have an output efficiency curve that should be taken into account when speccing a power supply for a particular equipment configuration.

Do it incorrectly, and your power supply will cost you more, over time, to run, and will not give you the maximum service life for the money that you invest in it. Usually, when an overloaded power supply dies--particularly if it's a low quality unit--it will damage, or outright destroy, pretty-much everything connected to it.

Calculate your maximum power consumption for a particular equipment configuration and, if you want to be quick about it, double that and purchase a power supply for that doubled figure--rounding up to the next even 150W interval.

If you want to spec the power supply properly, then you need to examine the power output efficiency curve for specific power supply models that you are considering, and select the power supply that puts your systems total power requirements at the peak of that curve. Generally-speaking, that is at the 50% to 65% loading point on the curve, for most contemporary APFC power supplies.

Building a computer isn't just slapping a bunch of parts together, tossing it inside a case, and hoping for the best. Done correctly, it is a process of engineering, and forethought, and too many people do not approach it from the proper perspective, and cause themselves more problems than they can count.
 
Aug 17, 2019
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Well for the most part you either have a good psu or a cheap one. You cant have both.
For quality, corsair rmx or evga gq/g2/g3 are all high quality.
As for wattage, you can go to a psu wattage calculator, or make a list on pcpartpicker, but make sure to have just a bit more wattage than the estimate
LOL , Rmx is not even comparable to evga GQ ... even the Corsair CX , with halfb ridge LLC primary topology is better than GQ... GQ is low-mid end at best. ACRF topology brings bad transients , especially at peak transient on higher end GPU... as well as being loud on high load
 

extreme_noob

Notable
Jul 30, 2018
408
25
840
11
Calculate your maximum power consumption for a particular equipment configuration and, if you want to be quick about it, double that and purchase a power supply for that doubled figure--rounding up to the next even 150W interval...
I know pcpartpicker doesnt, but don't most other psu wattage calculator sites already do this?
 

extreme_noob

Notable
Jul 30, 2018
408
25
840
11
LOL , Rmx is not even comparable to evga GQ ... even the Corsair CX , with halfb ridge LLC primary topology is better than GQ... GQ is low-mid end at best. ACRF topology brings bad transients , especially at peak transient on higher end GPU... as well as being loud on high load
Topology isnt everything but in this case youre right. Higher end modern specs would cause coil whine on gq. My mistake...
 

AllanGH

Estimable
Mar 10, 2019
2,552
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...don't most other psu wattage calculator sites already do this?
Most (not necessarily all, mind you) PSU power calculator sites are notoriously unreliable.

If you want the most accurate figures to work with, you would assess the power requirements for 12V, 5V, and 3.3V for every device in the system and calculate the total required power for each, then aggregate those power sums for total power requirement. In deliberating prospective PSU solutions, you do want to be mindful of the output capabilities of each rail, and make certain that, while you may be looking at PSUs that have an adequate total power output rating, you are not overloading any particular regulator output.

This is just part of the planning aspect of speccing a build.
 
Reactions: extreme_noob

FALC0N

Splendid
I'm not a fan of the CX series. Even the newer ones. They will do the job, but I prefer something with better build quality. When I am looking for a PSU in that price range, I wait until the S12II or M12II are on sale, but they are a little pricey right now. I would consider increasing the PSU budget a bit. You will find better options starting around $70.
 
I'm not a fan of the CX series. Even the newer ones. They will do the job, but I prefer something with better build quality. When I am looking for a PSU in that price range, I wait until the S12II or M12II are on sale, but they are a little pricey right now. I would consider increasing the PSU budget a bit. You will find better options starting around $70.
The Corsair CX grey units are superior to the S12ii and M12ii as the CX grey units are more modern.

The S12ii units lack OTP, so if your fan fails there is no way to prevent overheating. M12ii units do have OTP. Luckily S12ii and M12ii do have fluid dynamic bearing fans, so i doubt this is common.

The CX lineup has sleeve bearing fans, but they have OTP in case of a failure.

Also, since the S12ii and M12ii are older, they lack "Haswell Ready" certification, so they have sleep state issues until you tweak bios settings. The more modern CX grey units ar immune to this issue.

Both have 5-year warranties, 40c temp ratings, 80+ bronze certification (although some newer CX models are actually silver but marketed as bronze) and decent build quality.

I agree Seasonic FOCUS is good, hence the recommendation.
 
Reactions: TJ Hooker

FALC0N

Splendid
The Corsair CX grey units are superior to the S12ii and M12ii as the CX grey units are more modern.

The S12ii units lack OTP, so if your fan fails there is no way to prevent overheating. M12ii units do have OTP. Luckily S12ii and M12ii do have fluid dynamic bearing fans, so i doubt this is common.

The CX lineup has sleeve bearing fans, but they have OTP in case of a failure.

Also, since the S12ii and M12ii are older, they lack "Haswell Ready" certification, so they have sleep state issues until you tweak bios settings. The more modern CX grey units ar immune to this issue.

Both have 5-year warranties, 40c temp ratings, 80+ bronze certification (although some newer CX models are actually silver but marketed as bronze) and decent build quality.

I agree Seasonic FOCUS is good, hence the recommendation.
More modern isn't the same as superior. The S12II and M12II are built like tanks. I feel they have the best build quality, components, and ripple suppression of any PSU in that price range. I also think their real world performance is much greater than the sum of their parts. I have never had an S12II or M12II fail. I have never had any component attached to one fail. And I have used a lot of them over the last 13 years in a variety of capacities.

The points you made are also valid, and the current CX is a worthy opponent for sure. Corsair should be commended for producing such a fine DC to DC design at its price point, but I still prefer the superior build quality over the modern design in most applications.

This is one of the great things about building your own system. You get to make decisions like this on your own and prioritize the things that you feel are important instead of having a big company make those calls for you. I really think that more people should built their own systems. It's such a great experience all the way around.
 

TJ Hooker

Illustrious
Herald
More modern isn't the same as superior. The S12II and M12II are built like tanks. I feel they have the best build quality, components, and ripple suppression of any PSU in that price range. I also think their real world performance is much greater than the sum of their parts. I have never had an S12II or M12II fail. I have never had any component attached to one fail. And I have used a lot of them over the last 13 years in a variety of capacities.

The points you made are also valid, and the current CX is a worthy opponent for sure. Corsair should be commended for producing such a fine DC to DC design at its price point, but I still prefer the superior build quality over the modern design in most applications.
Care to provide evidence to support this? Anecdotes and personal feelings towards the M12II/SI2II don't count for much IMO.

Unfortunately I can't find any reviews that have crossloads tests for regulation + ripple for Seasonic PSUs, probably because of how long ago they were released. Components-wise the only thing that jumped out at me was that the CX units use some lower tier caps on the secondary side. Although I don't know enough about semiconductor manufacturers to say if the FETs used in one PSU are more or less reliable than those used in another.
 
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FALC0N

Splendid
Care to provide evidence to support this? Anecdotes and personal feelings towards the M12II/SI2II don't count for much IMO.
Care to provide evidence to support this? Anecdotes and personal feelings towards the M12II/SI2II don't count for much IMO.
You are new to this, aren't you, TJ Hooker? The S12II and M12II have been around for almost 15 years for a reason. Not only was it a huge factor in Seasonic's reputation as its best selling model, but companies like Antec, Corsair, and XFX build their PSU reputations in large part due to rebranded S12II/M12II's. During that time, they have been reviewed by many professional reviewers and the reviews were always stellar. Its reputation among users was second to none. About 5 years ago, multiple users on this very forum were arguing that it was better than PSU's costing twice as much, which I thought was a little crazy but it gives you an idea of its reputation.

It's the only PSU under $100 manufactured exclusively with 105 degree Japanese Caps on both the primary and secondaries for its entire decade and a half run. It a fairly rare example of a group regulated PSU that maintains ATX compliant voltage regulation under crossload. It maintains ripple in the sub-30mv range for almost its entire rated power range. A lot of $100 plus PSU's struggle with that. And it has well deserved reputation for lasting FOREVER without failure.

Now in the last few years, competition in its price range has increased while recent processor and chipset architectures have adopted power profiles that are harder on it than past cpu architectures. That has caused a few people to completely sour on it for reasons I don't agree with. Yes, its an aging design, but its the pinnacle of that aging design. If you are on a budget and can get it at the right price, its still a very good option.
 
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Power calculators can be deadly accurate IF... you have accurate inputs.
What might be your capacitor ageing?
What might be your future requirements?
What is the right safety margin?
and so on.
I find this chart to be most useful.
http://www.realhardtechx.com/index_archivos/Page362.htm
RX570 will be about 500w.

I have no problem overprovisioning a PSU a bit. Say 20%.
It will allow for a stronger future graphics card upgrade.
It will run cooler, quieter, and more efficiently in the middle third of it's range.
A PSU will only use the wattage demanded of it, regardless of it's max capability.

I would look for 550 or 650w.

Perhaps more important is the quality of the psu.
Some cheap units are downright dangerous and can destroy all they are connected to if they fail under load.
Less dangerous is a unit that tends to fail or is noisy.
Buy no less than a tier 3 unit from a list such as this:


I like the Seasonic focus units.
Seasonic usually has sales around this time of the year, so look for them.
This unit has a 10 year warranty.
https://www.newegg.com/seasonic-focus-plus-550-gold-ssr-550fx-550w/p/N82E16817151189

And... I would not buy that adata SSD.
On newegg, it gets some 39% one egg reviews.
https://www.newegg.com/adata-ultimate-su650-480gb/p/0D9-0017-00097?reviews=all

Much better is the Samsung 860 evo which is also much cheaper:
https://www.newegg.com/samsung-860-evo-series-500gb/p/N82E16820147674
You also might look at the m.2 format.
It needs no power or data cables.
The 970 evo is a pcie device with 4x the sequential speeds and still costs less than the adata:
https://www.newegg.com/samsung-970-evo-500gb/p/N82E16820147690
 
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