IRC #olimex 2017-07-16

[00:08:57] <nedko> adj__: right now zero. those on the background are still powered by olimex sold 1A or something PSUs
[00:09:58] <nedko> with the 5VSB line of the ATX power I plan to power at least two olinuxino A20s and two HDDs
[00:10:59] <nedko> the 12V line is rated to supply up to 33A, and this sounds like lot of olinuxinos to me :)
[13:07:16] <ShadowJK> 5VSB is good for 2A, right?
[13:33:09] <nedko> My ATX12V unit has +5VSB line rated at 2.5 A
[13:33:09] <nedko> i think the newer seasonic units are rated at 3.5 A
[13:34:10] <nedko> the fuse is 2A and the ATX module short cirtcuit protection is faster than the fuse
[13:34:26] <nedko> the fuse is required by the ATX PSU design guide
[13:35:11] <nedko> the fuse is not 2 but 2.5 A
[17:58:55] <diego71> nedko: buy a 5v industrial switch, it works better for olimex boards
[18:05:18] <diego71> like this: http://www.tme.eu/en/details/rs-25-5/industrial-power-supplies/mean-well/
[22:00:41] <nedko> diego71: better tha what?
[22:04:33] <nedko> *than
[22:16:40] <diego71> than using a PC psu
[22:16:51] <diego71> nedko: I think is a bit oversized :)
[22:24:53] <nedko> diego71: i think the X400 efficiency will get better when i add more modules to the cluster
[22:24:53] <nedko> and it is rated 80+
[22:24:53] <nedko> the industrial psu have industrial temperature range tough :)
[22:26:32] <diego71> nedko: efficiency is measured usally at nominal condition, if the psu is too much powerful, the efficiency can be lower
[22:27:10] <diego71> and usually psu consume also when in idle, so you can have a few watt "wasted"
[22:27:55] <nedko> yup, this is what i meant :)
[22:27:59] <diego71> if you have a powermeter you can check it
[22:29:05] <diego71> but which kind of board do you have to power?
[22:30:12] <nedko> right now they are all A20s from olimex
[22:30:16] <diego71> (If I remember well olimex lime consume less than 2W on idle)
[22:30:58] <nedko> HDDs also consume power, especially during spinup
[22:31:02] <diego71> do you need 5v or more? (lime or micro?)
[22:31:12] <nedko> right now i run both
[22:31:36] <diego71> so having 5v + 12v is bonus for you...
[22:32:08] <nedko> also i have a 12V ethernet switch
[22:32:12] <nedko> yup
[22:32:44] <diego71> I usually hd for netbook, so they need only 5v and they consume less
[22:32:54] <diego71> *usally use
[22:33:00] <nedko> also i can distibute 12V to bigger distances with smaller wires
[22:33:08] <nedko> i can have 12->5 buck convertes at the destination
[22:33:33] <diego71> but more converters waste some power :)
[22:34:01] <nedko> consume how much less?
[22:34:37] <diego71> except for the startup, consume about 1-2W
[22:36:03] <nedko> i dont have staged spinup yet :)
[22:38:27] <diego71> nedko: don't worry, they are a bit slow in startup
[22:39:10] <diego71> btw, if you have a gbit port, you can also think to have only 1HD, shared through nfs
[22:39:23] <diego71> (ofc depends on what you need...)
[22:41:05] <diego71> or better, you can use battery attached on the olinuxinos, so you have also a UPS (and you don't have to worry about power spike :) )
[22:41:09] <nedko> diego71: I don't worry, because this PSU can supply a lot :)
[22:41:09] <nedko> the 5V line is 100W
[22:42:10] <nedko> i'm more worried about grounding issues ;)
[22:42:10] <nedko> i have few olinuxinos with HDMI ports not functional anymore...
[22:43:23] <diego71> What is going to do your cluster?
[22:44:12] <nedko> Time will tell :)
[22:44:12] <nedko> I cannot really know right now :)
[23:37:27] <adj__> nedko, diego71: if you connect several boards with hdds and a gbit ethernet switch you can easily have a 80-90% efficiency with the atx psu even at idle
[23:39:06] <adj__> although expensive, 80 plus titanium have 90% efficiency at 10% load, more normal psus can have 80% at the same load
[23:43:22] <nedko> it is less expensive than an iphone... :)
[23:44:52] <diego71> nedko: if it's more expensive of all the olinuxinos, may be it's a bit expensive :P
[23:45:11] <nedko> the psu i use is platinum series
[23:47:13] <nedko> 90% at 10% load is very good efficiency. given that there are no fans
[23:47:25] <nedko> diego71: it is not more expensive than all olinuxinos and hdds i'm going to power from +5VSB
[23:48:15] <nedko> IIRC how much I paid for it...
[23:49:04] <diego71> i hope so, if you say less expensive than a Iphone, there is a lot of room ;-)
[23:49:21] <adj__> seasonic prime titanium is 90%/94%/96%/94% efficient at 10%/20%/50%/100% load, quite impressive
[23:49:30] <diego71> adj__: indeed
[23:49:40] <adj__> but yes, probably a 80 plus silver or gold makes more sense for something like this
[23:51:19] <nedko> why it makes more sense to you?
[23:52:58] <adj__> a lot cheaper, for just a few W wasted
[23:53:30] <nedko> less efficiency => more heat => fans
[23:54:21] <nedko> so i guess fans are not an issue for you
[23:54:22] <adj__> does gold or silver psus turn on fans at 10%?
[23:54:29] <diego71> nedko: how many olinuxinos do you have to power?
[23:55:22] <nedko> diego71: at least 10
[23:55:39] <nedko> adj__: no idea, but i don't want fmoving parts if possible
[23:55:49] <adj__> and at 50% load titanium only have 3%-4% more efficiency than gold. a better fan would make more difference for noise than the efficiency rating
[23:56:14] <diego71> nedko: hd have moving parts. You can use sd card
[23:56:23] <nedko> s/fmoving/moving/
[23:57:23] <nedko> adj__: best fan is the lack of fan :)
[23:57:41] <nedko> diego71: i know, but IMO HDDs are still better for long-term storage
[23:58:17] <adj__> I agree, you can trust your data more in an hdd, and price per GB is a lot lower
[23:58:19] <diego71> my home server is running on a olinuxino micro
[23:58:24] <nedko> also, i think i can use SSD :)
[23:58:36] <nedko> sd cards are generally smaller
[23:58:42] <diego71> SO is on sd, and I never need to change it
[23:59:13] <adj__> ssd are cheaper per GB than sd cards
[23:59:14] <diego71> often ssd consume more than aa HD
[23:59:25] <nedko> ATM my best common hdds are 500G
[23:59:25] <nedko> they are also quite quiet :)
[23:59:51] <diego71> adj__: of course, and are faster. Depends on how much storage you need