Looks like we know what to get, if the SeaSonic X-series doesn't provide enough power.

Another boring review of another boringly great PSU *

Is it too much to want a PSU like this in < 500W range and at < $ 100?

* smiley is here for joyless haters who need it to properly read the post...

Good review, thank you !

On page 4 : the * on the "Enermax Modu82+" line in the comparaison chart should either be removed (confusion with the other * in the chart) or replaced by another symbol to explain the complaints about noisier than expected fan in the Enermax (I believe that's what the * is for).

It might be boring, but it certainly gives us proof that unlike the latest Corsair HX psus, these Seasonic X-Series based corsair models are truly quiet like their pedigree was. I'm glad to see this and the X-series are definitely top recommendations for basically any high power system. :p

Also your want for a lower end power supply with similar characteristics might be satisfied by a Seasonic X-560. Hopefully that'll get close to the $100 mark. It will probably be my pick for a quiet mid-power psu.

Also I think the next psus of interest are the HCP and HCG made by Delta, very curious how quiet these guys will be.

Great review. Thanks!

Thanks for the review.

I'm thinking of grabbing one of these for a file server build now.

It's a decent assumption.

Hm, another rule which I feel it wasn't meant for people like me. I can understand it though.
This will be my 3rd post, I wonder if I can edit it later?...

LE:

Very nice PSU. I think my upgrade plans are unchanged though...as nice as 80PLUS Gold is, the CP850 costs 40% less, and has very similar noise performance whilst isolated from system heat.

Makes me wonder what the forthcoming Seasonic X-850 and X-1000 units are going to be like when they are released

I guess this sample also miss to reach 87% (and by far) at full load (exactly as the previously tested Cougar GX-700), while "real" Seasonics does (and Enermax almost too). May it be typical of Gold units above 650W?

Regards,
Luca

Probably. The impact of internal heat on efficiency is always more significant as you go up in power load. I don't see this as a serious failing on the part of the manufacturer -- it's really a serious flaw in the 80 Plus test procedure, which ignores operating/environmental temperature. I've reapeated myself on this point for so long and so many times (including directly to 80 Plus) that I hardly bother any more.

FWIW, the Corsair AX850 reached 89.2% efficiency at 700W out of the hotbox. This was the highest load I tested it with outside the hotbox, so it seems safe to say the unit would have made 87% at full power in "23°C ± 5°C" -- ie, max temp 28C. (Ditto 90% at half power at the same temp range instead of the 43~45C in my test.)

Apropos of methodology: what do you think, if any, about Oklahoma Wolf's own method?

Sometimes he's got substantially different numbers at full load: see M12D-850 reviews for a quick comparison, on SPCR it's clearly missed the Silver requirement, while on Jonnyguru it's easily got it, even in its own hot box at 43°C.

However things go different with the AX-850: at JonnyGuru it slightly misses Gold level at any testing point (sample variance?), but even not so definitely as in SPCR findings.

Regards,
Luca

Impossible to say what the causes of those differences are. Different loader; his is probably more accurate, as mine is more or less DIY. But it looks like my box gets a little hotter. No surprises there -- the exhaust is just one Nexus 120.

So the fan doesn't spin at lower loads/temperatures because the voltage going into it isn't high enough to start it spinning... Isn't the power going into the fan at this point just being wasted? Wouldn't it be more sensible to have the fan power completely switch off when it isn't needed?

Probably around 0.1W. It's not the most efficient way but it works because the fan has such low start speed & good bearings. PWM makes it work more the way you suggest but it's more costly, afaik -- which might be why it's not used in the Corsairs while it is used in the Seasonic X series.

PWM was used in the "old" X series X-650 and X-750. The "new" X-series such as the Seasonic X-560 use the same two wire non-PWM fan arrangement as the Corsair. So I guess this is another of those differences of detail between the older and newer generation of Seasonic X devices.