A few years ago i had the pleasure of reviewing the 600W Seasonic S12, which at the time was not as well known and revered as it is today. Seasonic had a growing reputation in the good ol' USA, but here in the UK it was difficult to find a distributor, let alone an e-tailer who had any of their units in stock. Needless to say, in blighty (UK) you only heard of 'Seasonic' when uttered in the shadows, and always on a winters evening... and there had to be a full moon, obviously. So, with my first encounter of a Seasonic power supply I went into the review expecting it to be OK - just a typical 600W unit, nothing more. As it turned out, a raised eyebrow or two later and i was pretty much shouting at the roof tops about the S12 600W, it's easily up there with the best 500 to 600W units ever made (sparkle, PC P&C, OCZ). Now Seasonic have introduced the M12 series with modular cables and a 700W model, it would be no understatement to say i'm as keen as dijon mustard to see if it's still up their with the best of 'em.

This review is a continuation of a recent mini-roundup of a few 700W power supply's, you can read the original article here if you wish, but i've done a quick copy and paste job of part of the introduction below as it's still relevant to this review:

This year [2006] at Computex, it was clear that power requirements for high end desktop machines are not going to slow down, in fact they are just about to get complicated. Every single manufacturer that dabbles with power supplies had small "add on" units on display designed specifically to power GPU's. It's interesting to note that Nvidia's 8800 series has now debuted, yet these add on units are not really the important addition 'they' said they'd be, and it's likely R600 will not be so excessive in power requirements to need one either. It's probable these units have been designed specifically to address issues far beyond simple SLI or CrossFire, like hardware accelerated physics processing utilizing three or more high end GPU's. Both Nvidia and ATI have committed to this path, its coming, and with it power requirements are going to creep up once again.

For now, however, the 600 to 700W units look to be the sweet spot for high end systems, they offer enough headroom for some serious overclocking, but not so much so that the extra premium for the unit was an absolute waste of money (1kw units anyone?).

Since i made that statement, some worrying rumours have been circulating that Van-DAMMIT's R600 is a 300W gobbling monster. I'm not sure how reliable this statement is, though it's a simple fact to state that recent ATI cards have continuously been the guzzling 4x4 (ooh pun so intended) of the GPU world. R600 CrossFire just might turn out to be a little too much for a 700W unit if these rumours are true, but it must be said, 300W just for the GPU doesn't sound right, we'll simply have to wait and see.

[19/03/2007] Now AMD have said they will be moving as soon as humanly possible to 65nm on R600 it looks as if the 300W power requirement per card will never happen.

In this review, I'll be taking a look at (you've guessed it haven't you?) the Seasonic M12 700W power supply. I'll be testing it under multiple conditions with X1900 CrossFire and a high end Core 2 Duo setup (X6800).