Cooler Master UCP 900 vs. Corsair TX850. Which is better?

[MinimalTech]

Hello there!

I'm MinimalTech, and i'm new here!

First of all i want to send my greetings to the forum's members and to the real Guru of PSUs, Jonny!! Jonny, i have read a lot of psu reviews, you are the best! I like very much your testing methodology and the sequence of the tests. Really, i find them very good and i think you make a professional job.

So, lets start tell you my "problem":

Lastly, i've read the Corsair's TX850 review. I find it a very good power supply for my new system. By the way, i'm already owned a Corsair VX450 power supply in my old system and i am very pleased from Corsair. The TX850 psu costs about 150 Euro in Greece (yes, i'm from Greece!).

By making a research in the market, i find also attractive the Cooler Master's UCP 900 power supply. They promises ultra safety, ultra efficiency and has something new (for me) on power supplies: the soft-start circuit which protects my unit. Corsair doesn't have this... I read also some, let me say, "amateur" reviews for that psu on the net but i didn't find what i need. None of them says anything about ripple and voltage noises (mV) on +12V, +3.3V and +5V rails... Sure there are inside ATX specs, but how much close to the limits they are? Also, as i read in Cooler Master's specs, this psu has an APFC value of 0.90 instead of Corsair's unit which has an APFC value of 0.99. Why is that? This unit costs 189 Euro in Greece.

Whats your opinion? Which psu you think is better?

All i want is a very stable, very efficient, noiseless, ultra protective for my system's parts power supply....:D

Thank you!

[Travis]

The PF value of APFC circuitry changes with load. At full load it's usually no less than 0.98~0.99, but at minimum load it's sometimes as low as 0.85~0.90, so it depends on how the manufacturer rates it. 80Plus certification requires PF>0.90 at full load or 50% load, which is easy to achieve. So no need to concern about it.

UCP 900 is significantly better than TX850 IMO. But neither is a "noiseless" PSU comparing to some silent ones nowadays.

[Oklahoma Wolf]

Lastly, i've read the Corsair's TX850 review. I find it a very good power supply for my new system. By the way, i'm already owned a Corsair VX450 power supply in my old system and i am very pleased from Corsair. The TX850 psu costs about 150 Euro in Greece (yes, i'm from Greece!).

By making a research in the market, i find also attractive the Cooler Master's UCP 900 power supply. They promises ultra safety, ultra efficiency and has something new (for me) on power supplies: the soft-start circuit which protects my unit. Corsair doesn't have this...

I've been doing all the PSU reviews here since January of 2008 or so, including that Corsair review. On page two, you'll notice I did three overshoot transient tests on that unit - these tests measure the turn on spikes on the rails when the unit is turned on. Unless these spikes go higher than 10% over the voltage spec for that rail (ie 13.2V for the 12V), or go into the negative range, the unit is considered to be in spec.

I mention this because if you look at those scope shots, the Corsair is well within the spec. No "soft start" circuit is needed, because it's already performing much better than the spec.

I haven't had a review sample for the UCP to know what it's like, but I can tell you the Corsair won't make you sorry you bought it.

Don't worry about APFC value - as mentioned it changes with load. I quit doing those tests because on just about every APFC unit I tested it usually stayed between 0.97 and 0.99. I started wondering what the point was, and dropped the PFC tests. So far, my readers don't seem to miss it.

[MinimalTech]

Ok, thanks guys for your quick response.

Oklahoma Wolf, please if you want you can see that (http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3364&p=1) review which i just found. It does not contain very special informations, but you can find out what parts includes. Also, to see the internals more analytically, you can browse the image gallery (http://www.anandtech.com/GalleryImage.aspx?id=3409).

To tell you the truth, i'm thinking of buying the UCP 900, as the AcBel Polytech made a pretty careful job inside the board (you can see the result from the pictures), it has choose and use good quality parts and they are all very trimly. The soldiering process is very well too instead of CWT's board for the Corsair TX850.

The only thing that i'm worrying about, is the noise ratio on +12V, +5V, +3.3V rails... I would like the +12V noise of the psu to be from 40 to 70 mV maximum for all different loads and circumstances.

What do you think? Is this psu capable of keeping this range of noise?

Also, do you believe that my phrase

a very stable, very efficient, noiseless, ultra protective for my system's parts power supply

stands true for the UCP 900?

P.S.: Why don't you make a review for the UCP 900 to test it and to figure all our questions out for that unit? That would be a very pleasant and a very powerful review...:fire:

[Oklahoma Wolf]

I can't tell how good the ripple suppression is just by looking at the guts - I'd need to test it. And I don't have a review sample, so I can't.

[Travis]

The "soft start" circuit is actually a relay which shorts the NTC resistor after the startup. This circuit is better than the NTC resistor alone in terms of efficiency, and also safety(if you turn on the unit shortly after it's turned off).

[Oklahoma Wolf]

Yeah. I should mention a few other units use that approach too like the Seasonic M12D and Antec Signature.

[MinimalTech]

So, do you suggest me to buy it or not?

Also, Travis, in your first post you mention that this psu is not noiseless at all. Can you tell me some example of a noiseless psu of this quality on 900W?

Thanks...

[cypherpunks]

They're both very high quality units. The anandtech.com review does mention the +12V ripple is extremely low at 8 mV (bottom of page 6). A commenter points to a techPowerUp review (http://www.techpowerup.com/reviews/CoolerMaster/UCP_900W/4.html) that claims higher (but still very good) ripple.

What I wonder is what you need an 800+W power supply for. Very few computers need that much power, and they're invariably extremely noisy. (You thought you could dissipate 800 W of power without fan noise?)

As for the power factor, don't worry. That's for the power company's benefit, not yours.

[Travis]

To name a few: Seasonic M12D 850, Enermax Revolution 85+ 850W, Zalman ZM850-HP are quieter at this level. The first two are also 80Plus Silver certified.

There might be some quiet units from other brands like Akasa/Nexus/Be Quiet!/Tagan(ITZ II 880W) but I'm not familiar with and I don't have test results to compare.

I don't know how sensitive you are to noise and what other noise source would appear in your build. If you do need a large-watt PSU you should check the noise of your VGA card cooler and chassis fan first -- they're often noisier than an average "quiet" power supply at typical load.

[MinimalTech]

All right, thats good news guys!

So i'll proceed to my order. I'm going to buy the UCP 900!


What I wonder is what you need an 800+W power supply for.

My new system generally contains a Core i7 920, a GigaByte ex58-ud4p mobo, 4 HDD SATA2 Drives, 7 x 120mm High performance fans, 2 x 140mm fans, 3 x DVD Drives (+ a Blue Ray Drive on the feature), a GTX285 Graphics Card (and in the feature i'm thinking of buying another one to make a SLI pc), and a SoundBlaster Platinum with front bay.

That's why i want a tough power psu. I want the psu to works without problems (restarts, over-temperatures e.t.c). I think a 900W psu its good for that build. Also, i'm worrying a little when i put the second GTX285 Card.. I think i will reach the limit of the UCP900, but, a UCP1100 is very expensive..

Travis, thank you also for your noissless solutions, but i have already shake down on CM's unit.

When i take it, i will write you my opinions from that psu! (about a week...)

Thank you all you guys!!

[cypherpunks]

To name a few: Seasonic M12D 850, Enermax Revolution 85+ 850W, Zalman ZM850-HP are quieter at this level. The first two are also 80Plus Silver certified.

Um, yes, I didn't mean that the power supply can't be quiet. 80+silver means that it's not getting too hot and doesn't need a lot of airflow.

What I was saying is that any computer that's consuming 750W is going to need a lot of airflow, and it's difficult to produce that much airflow without sounding like a leaf-blower.

It's also going to heat the room it's in just as well as one of those 900W space heaters you can buy.

It's simple conservation of energy: all the power going in has to go somewhere, and that means that it eventually becomes heat.

[cypherpunks]

My new system generally contains a Core i7 920, a GigaByte ex58-ud4p mobo, 4 HDD SATA2 Drives, 7 x 120mm High performance fans, 2 x 140mm fans, 3 x DVD Drives (+ a Blue Ray Drive on the feature), a GTX285 Graphics Card (and in the feature i'm thinking of buying another one to make a SLI pc), and a SoundBlaster Platinum with front bay.

That's why i want a tough power psu. I want the psu to works without problems (restarts, over-temperatures e.t.c). I think a 900W psu its good for that build. Also, i'm worrying a little when i put the second GTX285 Card.. I think i will reach the limit of the UCP900, but, a UCP1100 is very expensive..

Ah, yes, 2x GTX285 is a bit of a power hog. Budget 200W apiece for them. Your system's going to run something like 600W full-blast, so while a 750W PSU would be enough, 850–900W is some nice headroom.

You could put a third GTX285 in there and still not actually reach the limit of your PSU, though. 1000+W PSUs are really ridiculous.

[MinimalTech]

Hi cypherpunks!

With your phrases:



Ah, yes, 2x GTX285 is a bit of a power hog. Budget 200W apiece for them. Your system's going to run something like 600W full-blast, so while a 750W PSU would be enough, 850–900W is some nice headroom.

and


You could put a third GTX285 in there and still not actually reach the limit of your PSU, though. 1000+W PSUs are really ridiculous.

you make me not to regret for my purchase and feel happy for my choice!


Fortunately, as you say, the system can work well with the 900 watt and does not need to buy something bigger! CM's UCP 1100 costs 222 Euro in Greece. Indeed, i think too that a 1100 Watt unit is ridiculous...

So, cu in 7 days with the results and my experiences!!