which psu for antec p183[?]

[twitch]

Requirements:
1) Idle load expected to be < 70W (most likely between 50-70W ac pull from wall)
2) Full load expected to be < 100W (likely 70-120W max).
3) close to 24x7 operation
4) Would like to minimize ac --> dc conversion loss
5) need 6-13 sata power connections

I'm not convinced a pico psu / winmate would be upto snuff for a nearly always on system. Looked at the recommended list and here is the delta (ac --> dc conversion loss in watts) at different loads:

Code: Select all

ANTEC CP 850	
AC (w)	38	60	86	110
delta (w)17.1	18.6	22.5	20.2
				
Seasonic X400	
AC (w)	31	53	78	106
delta (w)	9.4	10.4	12.1	15.5
				
Enermax 87+ 500w				
AC (w)	33	56	78	103
delta (w)	11.2	12.6	12.4	14.5

I would have really like to use the antec cp 850 because that will keep the lower bay where the psu is (and the hdd in front of it) cool. But I lose an additional 10w (about $10/yr in electricity). Concerned about the heat buildup if I were to use seasonic x400. I'll have about 3 fans 120mm running about 800rpm (on rear, one front upper drive bay, one front lower drive bay - in front of psu).

[lodestar]

As you are going to have a fan in the front lower drive bay - in front of psu - I don't think you need to be concerned about heat build-up in the Seasonic X-400. Based on what you say the X-400 looks to be the best choice. I don't think though that you need to run the fan in front of it at 800rpm. A fan running at 500rpm would not only be ample but also quieter. Perhaps the Scythe Kaze Jyuni Slip Stream 120mm Fan, SY1225SL12SL.

[Parappaman]

Get that CP-850. Way overkill in terms of raw power, but perfect cable length, great stability, very quiet operation and excellent price. And you can ditch out a fan, which is worth a year of electricity, not considering what you're saving on the PSU...
Also, do note that when power reaches the 70-110w range, difference in wasted power gets less and less pronounced.

[twitch]

So far we have 1 vote for seasonic x400 and 1 vote for antec cp850.

BTW for cp850, the fan is PWM controlled. At light loads (<70 idle system where the system will be >90% of the time), the fan really has very little work to do and thus doesn't really move much air.

OTOH, for x400, at such low loads, the heat generated by the psu is a mere few degrees C. The cable length may be an issue. I'm going to have more hdd than the 5 sata power cables that come with the psu and will likely need Y cables (which should extend some but no idea how much).

[KayDat]

I vote for CP-850. I'm planning on getting one for my P183 as well. Not the most efficient, but it's still 80 PLUS. It's dirt cheap for such a decent PSU as well, you'd have to run it for at least five years before you make up the difference in cost.

[atmartens]

The cp850 also gives more head room for aging parts in the PSU and for upgrades.

[vatan007]

I reckon that If you'd want a silent psu, seasonic x fanless series are more silent than the cp850, right?

But the question is,... when does the fan kick in, how much noise does it make, and more importantly for this thread, how the hell do you build it inside of a antec 183. I can't wrap my head around it,... cause the fan of the seasonic will face wrong direction...?

[jhhoffma]

CP-850 FTW!