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First Look: Seasonic M12D 850W PSU

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Mankz 4th January 2009, 12:56 Quote
I would prefer to have either all modular PCI-E cables, instead of this 2+2 configuration.

Anyway, looks like a nice PSU.
naokaji 4th January 2009, 14:33 Quote
At that price competing against Corsair / Antec won't be easy...
Sure, Seasonic has a reputation for high quality psu's, but even for them 300 seems too much.
TomD22 4th January 2009, 15:11 Quote
"yay or neigh" :D There a horse in the office?

-- 'yea or nay'
DorkSterr 4th January 2009, 15:25 Quote
Wow It seems like all PSU are going modular now. I still think the Ultra X3 ULT40312 850-Watt is the best PSU out there 100% modular!!
Bindibadgi 4th January 2009, 16:11 Quote
Quote:
Originally Posted by TomD22
"yay or neigh" :D There a horse in the office?

-- 'yea or nay'

No, a Camel
eXpander 4th January 2009, 18:52 Quote
Quote:
At 850W it's the highest wattage PSU Seasonic has ever launched, where as everyone else has chased the four digit threshold that very few people care for, instead the new frontier in PSU technology is efficiency.

Finally, someone said it!

I`m no electrical expert, but i just got confused when other sites were recommending 1000W+ PSUs, while a QX7000 OC`ed and a HD4870X2 in were only consuming something like 500-600W peak wattage. So these are just cases where we need to apply our BS filter, right?
Bindibadgi 4th January 2009, 19:15 Quote
Quote:
Originally Posted by eXpander
Finally, someone said it!

I`m no electrical expert, but i just got confused when other sites were recommending 1000W+ PSUs, while a QX7000 OC`ed and a HD4870X2 in were only consuming something like 500-600W peak wattage. So these are just cases where we need to apply our BS filter, right?

Not really - most PSUs optimal efficiency is about the 50-75 percent range, so for 500-600W system an 850-1,000W PSU is pretty good, but few people own multi-GPU high end.
E.E.L. Ambiense 4th January 2009, 19:31 Quote
Seems like that sweet spot that the higher-end people were looking for in terms of a modular PSU that wasn't 1600+ Watts or so. I'm pretty sure this is a perfectly fine PSU as well. Seasonic has a bit of a reputation. ;)
eXpander 4th January 2009, 19:45 Quote
Hey, thx for the reply.

But i`m still a bit confused regarding efficiency:

I also assumed that for a 50% efficiency (just using a low round number for easier comparison), if your system needed 300W, you would have to have at least a 600W PSU. But from what i read a while ago (don't remember the site exactly), i understood something like this: If you have a 500W with 50% efficiency, it DOES provide 500W, but it draws 1000W from the wall socket, therefore increasing your electric bill. Again, i`m exagerating with the percent, for easier comparison.

I am also puzzled about the fact that my PSU is 280W, and i used an HD4870 512MB and 2x HD4850 CrossFire on my EP45-DS3 with my trusty E2140, running at 3.2GHz (100% OC) and I didn't have any problems. No artefacts, no restarts. I also tested my system with a Gigabyte Superb 720W and i got the same results. By my calculations, my PC should've ran out of juice with my regular PSU :)

Can you explain pls?
Ending Credits 4th January 2009, 20:21 Quote
He means PSUs are most efficient at converting wall power into usable power (therefore running cooler and wasting less electricity) when they're 50-75% loaded.

280W is probably the power draw of a generic system with a 4870X2 installed so you're at the limit but not over it (check the reviews where it says total power consumption of the system with the GPU installed).
Quote:
I also assumed that for a 50% efficiency (just using a low round number for easier comparison), if your system needed 300W, you would have to have at least a 600W PSU

No, you need a 300W PSU but it'll draw 600W from the wall (therefore wasting 300W which heats up your system and costs money).
Bindibadgi 4th January 2009, 21:58 Quote
Quote:
Originally Posted by eXpander
Hey, thx for the reply.

But i`m still a bit confused regarding efficiency:

I also assumed that for a 50% efficiency (just using a low round number for easier comparison), if your system needed 300W, you would have to have at least a 600W PSU. But from what i read a while ago (don't remember the site exactly), i understood something like this: If you have a 500W with 50% efficiency, it DOES provide 500W, but it draws 1000W from the wall socket, therefore increasing your electric bill. Again, i`m exagerating with the percent, for easier comparison.

I am also puzzled about the fact that my PSU is 280W, and i used an HD4870 512MB and 2x HD4850 CrossFire on my EP45-DS3 with my trusty E2140, running at 3.2GHz (100% OC) and I didn't have any problems. No artefacts, no restarts. I also tested my system with a Gigabyte Superb 720W and i got the same results. By my calculations, my PC should've ran out of juice with my regular PSU :)

Can you explain pls?

Lets take a 500W PSU for example:

If the PSU was "50% efficient" (very poor) => 500W output by the PSU itself (500W being drawn by the system to CPU, graphics, HDD etc - and FULLY LOADING the PSU) = 1000W required at the wall socket. Therefore, that extra 500W more is being lost between AC socket and your components as heat.

Now, normally instead of "50% efficient", PSUs these days pull 80, usually 85+% efficiency for good ones, meaning fully loading a 500W PSU will cause 575W to be drawn at the wall, losing only 75W as heat. Likewise, fully loading a 1000W PSU at 85% efficiency = 1150W at the wall, 150W lost as heat - twice as much lost for twice as much power used.

The "efficiency curve" is measured across the load scale - normally the 80Plus program uses load levels that are 20% (idle), 50% (typical) and 100% (full). For a 1000W PSU those load levels equate to 200W, 500W and 1000W DC output (NOT at the wall socket).

The efficiency normally translates like this: ^ starts low, goes high in the middle, then dips again. Usually, a PSU reaches maximum efficiency at around half load (50%) but it depends on the design. Look at the bottom right hand picture here: http://images.bit-tech.net/content_images/2009/01/preview-seasonic-m12d-850w-psu/paper3-8.jpg

So, if we load a 500W PSU to 50% DC output, but it's 85% efficient we have:

500 x 50% = 250W PSU load (DC output)
250 x 1.15 (85% efficient = 15% loss) = 287.5W AC drawn at the wall.

Your 280W PSU should have blown its tits off tbh - you were lucky imo :p If it was built well it would have overcurrent protection and would just cut out.
g3n3tiX 5th January 2009, 19:00 Quote
Very nice explanation and first look and the PSU.
I bet you did the load tests, while you can't publish them, was the PSU actually 80+ silver ?
Bindibadgi 5th January 2009, 19:03 Quote
Quote:
Originally Posted by g3n3tiX
Very nice explanation and first look and the PSU.
I bet you did the load tests, while you can't publish them, was the PSU actually 80+ silver ?

I haven't loaded it properly, otherwise I would have published the results. The only independent results we have are from the 80Plus certification.
tonschk 5th January 2009, 22:27 Quote
Too bad this is a modular PSU , modular PSU are less efficient due to the extra unnecessary connectors , I will never buy a modular PSU , I can hide very easy all the cables at the back of the mobo tray of my coolermaster case , therefore modular PSU not necessary , I am choosing between the Coolermaster UCP 900W , the Silverstone OP-Evolution 850W Olympia , or the new Corsair TX850W , I love the non modular PSU, professionals don`t use modular PSU

http://i194.photobucket.com/albums/z58/tonschk/Image0003.jpg
E.E.L. Ambiense 5th January 2009, 23:09 Quote
Quote:
Originally Posted by tonschk
Too bad this is a modular PSU , modular PSU are less efficient due to the extra unnecessary connectors , I will never buy a modular PSU , I can hide very easy all the cables at the back of the mobo tray of my coolermaster case , therefore modular PSU not necessary , I am choosing between the Coolermaster UCP 900W , the Silverstone OP-Evolution 850W Olympia , or the new Corsair TX850W , I love the non modular PSU, professionals don`t use modular PSU

:) You're kidding, right?

The efficiency barely takes a hit due to the modular cables if at all. I'd try a Google search.

Professionals don't use modular PSU's, huh? Take a look in the project logs!
Bindibadgi 5th January 2009, 23:42 Quote
Quote:
Originally Posted by tonschk
I love the non modular PSU, professionals don`t use modular PSU

Meh, that's mostly FUD and elitist PC Power and Cooling talk.

How come the MODULAR be quiet PSU tops our efficiency list? And this Seasonic does incredibly well also? And the Antec Signature, which is semi modular, does better than the CM UCP 900 at 20% load?

To be honest - not using 16 AWG (or thicker) wire has more or as much potential effect on efficiency as a modular connector. As long as it's well made and the connection is secure, it's not an issue. Normally it's user error that's the problem but manufacturing faults can come into play to.

A few percent efficiency makes very little difference compared to the convenience of only using the cables you want and keeping your system cooler. If you have a case to pack them away neatly - good for you!! - most of us don't :)
tonschk 6th January 2009, 07:49 Quote
;) Fortunately I have a case able to pack the cables away neatly , therefore modular PSU are not necessary ;)
http://i194.photobucket.com/albums/z58/tonschk/Image0022-1.jpg
http://i194.photobucket.com/albums/z58/tonschk/Image0003.jpg
tonschk 6th January 2009, 15:56 Quote
I will never buy a modular PSU because I want to keep a tidy case and the Modular PSU are messy with plenty of Ugly connections and silly LEDs

http://i194.photobucket.com/albums/z58/tonschk/BZ900.png
http://i194.photobucket.com/albums/z58/tonschk/ABT_1000_fan.jpg
Bindibadgi 6th January 2009, 16:05 Quote
Quote:
Originally Posted by tonschk
I will never buy a modular PSU because I want to keep a tidy case and the Modular PSU are messy with plenty of Ugly connections and silly LEDs

You're extrapolating a lot from a single example, especially when the Seagate ones are black and the case is black.

I don't understand how you claim modular PSUs are messy when they have less cables.
tonschk 6th January 2009, 18:31 Quote
Quote:
Originally Posted by Bindibadgi
I don't understand how you claim modular PSUs are messy when they have less cables.

Are you blind ? where can you see less cables , in the Seasonic 650W PSU installed in my case or in that Horrible and Silly Tagan BZ serie 900W PSU ?
Bindibadgi 6th January 2009, 18:44 Quote
Quote:
Originally Posted by tonschk
Are you blind ? where can you see less cables , in the Seasonic 650W PSU installed in my case or in that Horrible and Silly Tagan BZ serie 900W PSU ?

That's because all the cables are plugged in and it's just a single example!

If you need all the cables, why buy a modular PSU?
E.E.L. Ambiense 6th January 2009, 19:57 Quote
Quote:
Originally Posted by Bindibadgi
That's because all the cables are plugged in and it's just a single example!

If you need all the cables, why buy a modular PSU?

LOL!!

I think he's just trying to rag on modular PSUs as a whole, Bindi, not necessarily because he's buying one or anything. If he doesn't like modular PSUs, that's his choice and/or problem. But honestly, the bottom line is that I've seen no proposed compelling argument against them at all other than saying they're horrible, etc. :) Which is frankly starting to border on childish bicker. Personal taste doesn't count! That would equate to me saying I don't like Ford automobiles because they suck-- oh, wait...bad example. ;)

Personally, I look for modular PSUs when I build a new rig, either for myself or commissioned. I've had no problems at all.

I guess this comes down to the same argument about Blu-Ray Disc. I always just say, "buy it if you want it; don't buy it if you don't want it!" Common sense, right? :)
Bindibadgi 6th January 2009, 20:45 Quote
Yes, absolutely. Tom's setup is very, very neat, but there are also advantages in a modular PSU as well in providing neatness in other types of cases and builds.
thehippoz 7th January 2009, 03:42 Quote
does this psu have issues? there's only one review on newegg and the guy said it blew up and caught on fire- and it's deactived =] the ripple on jonny guru looked pretty sick.. and 90% eff under certain loads

I dunno how you can beat corsairs 850tx right now as far as bang for the buck.. under 70mv ripple (the 750tx was <100mv) this seasonic looks like <40mv (sick)

on buy.com, free shipping and a $20 rebate, the 850tx is only $127 US shipped including tax.. $117 if your new to google checkout
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