My only questions are:

What do 550LT and 650KM translate to in retail product names?

Will they be available in the US?

When and When (review by SPCR and for sale in the US)?

It'll be a while. Probably mid next year.

Near the bottom of Page 1.



I assume that there is a typo there relating to the environmental temperatue, and its +/- 5% and not =/- 5 Degrees Celcius.

What out of interest is special about 23 Celcius, (ignoring the obvious fact that its not realistic for the vast majority of PC's) I assume there has been some kind of study into average room temeratures and they ended up with 23C.?

Also, I have just flicked back a few pages and Googled the model No. for the fan. 3-hits (4/5 later possibly including this one), Anandtech, PC-Experience and one in our forums talking about this PSU.

http://www.google.co.uk/search?hl=en&q= ... arch&meta=

This is only interesting due to the lack of hits and that they are pointing at this PSU, is it specially made for SS by Sanyo-Denki.?


Andy

I think the 80+ temp spec was added only after I discussed the issue with them. I brought it up to them when they asked my opin about testing procedures before the program was launched, and they kind of shrugged at the time, but I've persisted in email exchanges and in my reviews, so they probably decided something should be said about temp. I think it's a meaningless spec, mainly designed to cover their b..ts and the range of temps they see in their lab.

I appreciate their difficulty, they want to encourage not discourage high efficiency PSU development, so SPCR's test technique would be anathema by making it too hard. On the other hand, every PSU maker has temp controlled test chambers, and they could just defined 40C as the test spec. They would have to get one of those, too, of course, and a tester that could work in such an environment -- or remote cabling. All of which adds to cost, but surely by now, the 80+ program is generating good cash flow. Dunno. Haven't been in touch with them for a while.

As for the fan, yes, it's exclusive to Seasonic, I wrote that in the review.

Hiya,

It is a fine looking fan -- the blades sweep forward at a greater angle than most, and all the rounded corners and edges must help it stay quiet. The blades' leading edge is a gentle angle, and then the pitch increases (which makes them look scooped), which accelerates the air more gradually. The base of the blades are filleted and strengthened at the hub. And you can oil that bearing...very fine indeed.

Do you think the fan behaviour of the 750 W model is the same at output <= about 400 W or it's expectable for the fan to ramp-up before?

On the efficiency chart, I calculate the efficiency at 22 W DC output to be 40% rather than the 62.2% stated in the chart. (22 W/55 W = 0.40)

The efficiency at other loads I get more or less the same as you get. I guess the only difference is rounding off at the first decimal. But IMO you're being generous at 22 W load.

I agree with your thoughts, Mike C, that reviewing high wattage PSUs are not very interesting for this site. I know they're bronze/silver rated, but that doesn't make them very effective for the average PC end-user. In fact, I think that all the high watt silver/bronze rated PSUs are devaluating the meaning of having the 80-bronze-silver-gold rating system. Because if some guy wants an effective PSU and just take the PSU with the best rating available, he is likely to end up with pricier and worse PSU than he might get if he bought a lower rated PSU.

AnandTech wrote:


However...... I think it would be interesting a comparison between this Seasonic and the 850 W version of the Enermax Revolution 85+.

20w effic. -- need to check original spreadsheet - probably a transcription error. edit -- yup. AC input should have been 35W, not 55W.

I disagree w/ the Anandtech comment about voltage vs pwm control fans. The guy who wrote that hasn't listened to enough fans.

Interesting to you or not, we will continue seeing big fat power supplies, and it's not wise for us to ignore them. However, in the near future, we will differentiate between superpower & "normal" psus, the arbitrary line probably being ~650W. They won't be tested in exactly the same way. Main difference being amount of cooling airflow.

Thank you for your good work MikeC

I always reference to SPCR when it comes to fans, this site is the only place I trust for proper reviews of fans, psu's etc. Not withut merit.

THG used to be decent enough, but really went down the shitter, and it seems Anand is slowly following down the same road, its sad.

back on topic.. this psu looks really promising, might use it in a norco 4020 when im upgrading monster to a full blown rackmount.

Ok this PSU is obviously really good and all, but who can afford it...

Me, if I needed 850W.

A very good PSU indeed but horribly priced. Signature 850 is a tad cheaper, TX850 is more than half cheaper and ES-800 is one third from Seasonic's price.
I really don't see a good reason to buy this Seasonic now.

Now all we need is for seasonic to chop of half its rated wattage, drop the price by similar levels and we'll have yourselves a fantastic PSU.

Someone with a 30" monitor?

Excellent review Mike, and as always superbly written, perhaps one of the best PSU reviews to date.

Regarding the unit? Well, for magic you go see Seasonic.

FYI, I'm offering a modded earlier sample of the Seasonic M12D-850W for $125 shipped.

Hello,

That was a very nice review.. It's good to hear that there are more powerful PSU's out there that don't sound like a jet engine.

I recently switched to an Enermax Modu82+ 625W (after reading the review here), and I'm really happy so far. The old PSU was an Epsilon 600W, so the change was not for more power but less noise.

I'm a bit jealous to see that there's now a quieter PSU (under 400W), though.

(I thought "The results are for a 425W Enermax; so the 625 would be quieter at <400", but the results are interpolated for 625 so I can hope for a draw at best..)

Anyway; I can hear the PSU only when I put my ear next to it; so I really don't need a more quiet one

No way!

My 30" monitor, which I now have had for almost a year, is without a doubt the best upgrade/investment I have ever made to my computers. I can have 2 windows 1280 pixels wide side by side, without the hassle and inconvenience of a dual head setup. My previous setup was a dual head setup that I used for more than 5 years and didn't want to go that way anymore.

I don't have a TV, I don't have a video projector, and I only have one monitor, and I use this computer for doing my job (I work from home), studying and leisure time activities, so spending on this one large monitor makes sense to me. IMHO the monitor is the most important part of a personal computer, because you stare at it all the time when you use the computer.

None of the other upgrades I have made, Q9450, 8GB RAM, Velociraptor, etc... come even close to the improved ergonomics, work efficiency and user satisfaction I get from this monitor versus all the other monitor setups I ever had, and I did spend money on those earlier ones too.

On the other hand, a PSU is just a power source. If it works, you are not supposed to notice it. Only when it starts to give you trouble, should you start to notice it. Unlike most things reviewed here, this PSU is just so damn expensive for being just a power source, that I'd expect it to file my taxes and make me coffee to buy it.

I don't deny it's perhaps the most technically advanced PC PSU I have seen, but it's basically like a sports car: Few people can justify to buy something like that, unless they are loaded with money.

That's a fair point. I just thought that as that particular monitor costs around £1100 in the UK; and with the rest of your set up being quality stuff, the extra cost of the power supply would go unnoticed...
I'm also a little envious, as your system is almost exactly what I would love to have sitting on my desk if I could afford it.

I thought I'd enlighten you guys about the distribution of the 12V rails, or rather let jonnyguru take over from here.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=127

Now that's actually a link to the whole review but there is a picture of the PSU with it's fan upwards and jonnyguru writes the following:

"The rail distribution is a bit funky on this, but Seasonic was kind enough to enlighten me. From left to right in the above picture, the connectors are: 12V1, 12V1, 12V2, 12V2, 12V1, 12V2. This means that the PATA/SATA connectors are evenly divided between the two 12V rails, as are the PCI-E connectors. The hardwired cables are similarly divided - 12V2 for the EPS12V and ATX12V cables and one of the PCI-E cables, with everything else on 12V1."

So there you have it. Very nice.

The distribution of the modular connections could also be found if you took apart the PSU and looked at the modular connector PCB which has the rails printed below the connectors. I really wouldn't suggest this if you really don't know what you're doing.

Please give the guy credit. OklahomaWolf did that review not Jonny.

Some people never pay attention to by lines. Not saying you are one of those people but for the ones that don't bother to follow the link I'm adding credit to the quoted material.

Excellent article. I've been following SPCR for about 5 years now. Your testing procedures keep getting better. Very impressive.

I heard about the M12D-850 on some other web-site and I'm considering purchasing it. What has held me up is the price. However, with this review it does provide convincing evidence of the M12D's utility (and silent operation).

About the only question I have at this point is, how does the M12D-850 compare to Koolance's PSU-1300ATX-12N ? While the M12D is expensive, it's half of what the PSU-1300 is. M12D's output regulation and efficiency look superb, could the PSU-1300 even come close in that regard? Etc. [Of course, the PSU-1300 is potentially a wee bit quieter, being water-cooled].

Again, thanks for the well written article.

ekv -- Thanks for the comments.

As for the Koolance, hardocp has reviewed it. There are 3 issues I'd take with the the Koolance --

1. who needs 1300w?
2. it might not make noise, but the wc system it needs to run surely will. In our experience, wc is not quieter, it adds one more noise source: the pump.
3. price - $625??

ignoring the issue of cost, this wouldn't be a bad PSU for anybody - efficiency at the AC draw most peoples PCs work at (70-110W I'd guess) is still good from ~75-82%. Plus you essentially have a silent PSU up to 400W DC, which is about as high as even a pretty hardcore gamer PC gets. So it might be expensive and have a high power rating, but that doesn't mean it isn't suitable for a wide range of PCs. Even at the level my PC idles at (40W) it would still be more efficient than my current overkill 400W PSU (and cost as much as my whole PC!)

The 1300W Koolance PSU has a very wide high-efficiency band from which to mix-and-match components into your computer. My situation is rather far from HTPC in that I'd like to run 4, or 6, or 8 monitors ... um, for development, yeah, that's the ticket, development

Mike makes some very good points. I'm impressed by the M12D-850's low ripple output and silent operation, which his testing showed, even under heavy load. I may have to wait a bit on the price coming down, since there are a few other components I'm budgeting-for / building.

The M12D is a good investment. Believe me, you do not want to skimp on your PSU. It's good insurance, peace-of-mind, etc.

It seems that the hardmounted fan transmits vibrations through my aluminum case. When I get some time I'm going to open it up and softmount the fan.
Warranty on my unit is already void anyway...

EDIT: There is no space between the fan and heatsinks! So much for softmounting.

The best power supply I owned to date, this one is a keeper.

Excellent review MikeC , as always.