Re: [OT] ATX-PSU and amperage on connectors...
On Sun, Mar 02, 2008 at 01:30:43PM +0100, Michelle Konzack wrote:
> after rereading the ATX12V specification I have some questions as
> non-native english speaker... :-)
>
> Am 2008-02-22 11:51:59, schrieb Douglas A. Tutty:
> > So the only trick for your design is what plugs from the PSU are on
> > which 12V bus. Here's the breakdown:
>
> Right...
>
> In the ATX12V specification (version 2.2) it is written:
>
> ----8<------------------------------------------------------------------
> 1.2.1. Increase +12 VDC output capability
> System components that use 12V are continuing to increase in power.
> In cases where expected current requirements is greater than 18A a
> second 12 V rail should be made available. ATX12V power supplies
> should be designed to accommodate these increased +12 VDC currents.
> ----8<------------------------------------------------------------------
>
> The Iout on 12V2 is between 13A (200W PSU) and 16A (450W PSU) from
> the specs.
Then that will fit on the one 12V2 rail since its less than 18A. My
guess for the reason for the 18A limit is to limit the size of the wire
required.
>
> ----8<------------------------------------------------------------------
> 1.2.2. Main Power Connector
> The 2 x 10 main power connector has been replaced by a 2 x 12
> connector. This was made to support 75 watt PCI Express*requirements.
> Pinout assignments are based on the SSI recommendation. With the added
> 12V, 5V, and 3.3V pins the need for an Aux Power connector is no
> longer needed and the guidance for this connector has been removed.
> ----8<------------------------------------------------------------------
>
> I assume the AUX-Power connector was the 6pin connector with 3x GND,
> 2x 3.3V and 1x 5V
Don't know. I went from a PSU with only a single connector to the MB
and the drive connectors (on my 486, a P-75, and a P-II), to my athlon64
with the PSU for which I sent specs. No doubt there were PSU specs
in-between which I have never seen.
>
> ----8<------------------------------------------------------------------
> 1.2.3. Separate current limit for 12V2 on the 2x2 connector
> The 12V rail on the 2 x 2 power connector should be a separate current
> limited output to meet the requirements of UL and EN 60950.
> ----8<------------------------------------------------------------------
They're talking about a current limit for this one connector, which
comes off of a bus with a, presumably, higher current limit.
>
> And here it begins where I do not know... because:
>
> ----8<------------------------------------------------------------------
> 3.2.3.1. ATX12V Configurations
> Table 3. Typical Power Distribution for a 250 W ATX12V Configuration
> Min. Max. Peak
> Current Current Current
> Output (amps) (amps) (amps)
> +12 V1DC(1) 1 8 9
> +12 V2DC (1, 2) 1 13 16.5
> +5 VDC 0.3 12
> +3.3 VDC 0.5 14
> -12 VDC 0 0.3
> +5 VSB 0 2.5 3.5
>
> Note: Total combined output of 3.3 V and 5 V is 115W
> Peak currents may last up to 17 seconds with not more than
> one occurrence per minute
> (1) 12V1DC and 12V2DC should have separate current limit circuits
> to meet 240VA safety requirements.
> (2) 12V2DC supports processor power requirements and must have a
> separate current limit and provide 16.5A peak current for
> 10 ms; minimum voltage during peak is > 11.0 VDC
> ----8<------------------------------------------------------------------
>
> So note (2) say: "12V2DC supports processor power requirements" which
> mean the ATX-Connector is on 12V2.
>
> Is this right?
Don't know. What did the specs for my PSU say? Remember, there are two
connectors to the MB now, both called "ATX" just to be confusing.
>
> Then I have a problem to understand HOW 13A on 12V2 can support the ATX-
> Connector and the 2x2 12V connector. This make for me no logic...
>
> E.g. 5V + 3.3V can be only 115W, but 12V2 is 13A = 159A => the rest is
> then maximum 44W which mean, a maximum of 3.66A for the 2x2 connector.
>
> From the ATX12V specification:
>
> ----8<------------------------------------------------------------------
> 4.5. DC Connectors
> <snip>
> 4.5.1. ATX Main Power Connector
> + 3.3V => taken from 12V2
> + 5 V => taken from 12V2
> +12 V => taken from 12V1 (!!!)
>
> 4.5.2. +12 V Power Connector
> +12 V => taken from 12V2
>
> 4.5.3. Peripheral Connector(s)
> + 5 V => taken from 12V2
> +12 V => taken from 12V1 (!!!)
>
> 4.5.4. Serial ATA Power Connector
> + 3.3V => taken from 12V2
> + 5 V => taken from 12V2
> +12 V => taken from 12V1 (!!!)
>
> 4.5.5. Floppy Drive Connector
> + 5 V => taken from 12V2
> +12 V => taken from 12V1 (!!!)
> ----8<------------------------------------------------------------------
>
> But A friend of me has tested the 2x2 12V P4-Connector and it hit
> arround 16A using a P4/4000 which mean, even a 450W PSU (from the
> specs) would not support this PIG since 12V2 has only 16/19A.
>
> Even my CobaKing VP-420-5120 with 20A on 12V1 and 18A on 12V2 will
> be killed.
>
> > 8 pin 12V power connector: pins 1 & 2 are from bus 1, pins 3 & 4 from
> > bus 2.
>
> This connector is not mentioned in the ATX12V specification...
>
> > One PCIe 6 pin connector is on bus 1, the other PCIe 6 pin connector is
> > on bus 3 (these are for one or two video cards that need the extra
> > power)
>
> This connector is not mentioned in the ATX12V specification...
>
> Since I try to create a module 24V DC ATX PSU, I am thinking on:
>
> 1. ATX Power Module
>
> 24V ---> 12V ---> 12 V with 20A (34-240W usable)
> > 5 V with 20A (100W)
> > 3.3V with 20A ( 66W)
>
> 2. 12V Power Module
>
> 24V ---> 12V ---> 12 V with 20A (200W)
>
> 3. Peripheral Power Module (incl. FDD; up to 4 HDD or 2 DVD-Burner)
>
> 24V ---> 12V ---> 12 V with 6A (52-72W usable)
> > 5 V with 4A (20W)
>
> 4. Serial ATA Power Module (up to 4 HDD or 2 DVD-Burner)
>
> 24V ---> 12V ---> 12 V with 4A (8.5-48W usable)
> > 5 V with 5A (25 W)
> > 3.3V with 5A (16.5W)
>
> Also I should mention, that I have found at <http://www.national.com/>
> High-Voltage Step-Down-Reculators for 12V Output up to 25A and on
> <http://www.maxim-ic.com/> Dual Step-Down-Reculators for 3.3V/5V and
> up to 25A each (at the same time). Also I will use the MAX16025/27/29
> to get the Voltages started/stoped in the right sequence.
>
> > I suppose the question is how much of a computer do you intend to power
>
> I will use only VIA EPIA LN10000EAG (1GHz) and the same MB in 500Mhz.
>
> > on solar power? Do you need a video card that requires a PCI-e? How
>
> VGA On-Board and it should be suffsant for Bureau & Internet
>
> > many drives do you want to be powering? I don't want to open up my box
>
> This is, WHY I wnat o use ,e.g., Hitachi TravelStar E5K or E7K series
> which are for continious use and have 5V/1.4A (or less). But I put it
> on a 3Ware 3w8500S-8LP with 7 Disks (2+1 for OS in Raid-1 and 3+1 for
> Data in Raid-5)
>
> In the Workstations I will use a SanDisk UltraII 2 or 4 GByte.
>
> Note: on my IBM ThinkPad 570 (P2/366/192MB) I am running Sarge with
> "fvwm", "mozilla" and "oowrite" plus "xmms" and "xterm-mutt" parallel
> and my 200 MByte SWAP is only touched 16-30 MByte. So a VIA EPIA with
> 1 GByte of memory should be enough to avoid the use of a SWAP.
>
> So in summary I have:
>
> 1) 2 x Workstations
> VIA EPIA LN10000EAG
> 1 GByte memory
> SanDisk Ultra II 2 GByte
>
> ~ 20 Watt each
>
> 2) File Server (nfs-kernel-server, apache, php5)
> VIA EPIA LN10000EAG
> 1 GByte memory
> 3Ware 3w8500S-8LP
> 3 x Hitachi TravelStar E5K160 60 GByte
> 4 x Hitachi TravelStar E7K250 250 GByte
>
> ~ 80 Watt
>
> 3) Mail Server (courier, procmail, fetchmail, spamassassin, clamav-ng)
> VIA EPIA LN10000EAG
> 1 GByte memory
> 3Ware 3w8500S-8LP
> 3 x Hitachi TravelStar E5K160 60 GByte
> 4 x Hitachi TravelStar E6K160 60 GByte
>
> ~ 80 Watt
>
> 4) Database Server (postgresql)
> VIA EPIA LN10000EAG
> 1 GByte memory
> 3Ware 3w8500S-8LP
> 2 x Hitachi TravelStar E5K160 60 GByte (Raid-1 without Hotfix)
> 6 x Hitachi TravelStar E7K250 250 GByte (2x Raid-1 with Hotfix)
>
> ~ 80 Watt
>
> 5) Router
> ??? (maybe ARM11 based but not found the right mainboard currently)
> 512 GByte memory
> SanDisk Ultra II 1 GByte
> 4 x MiniPCI Atheros WiFi 802.11a (5Ghz)
> 2 x NIC 10/100 MBit
> 2 x Nokia 6120 classic (two GSM/UMTS/HSDPA gateways)
> 4 x Siemens S40 (for receiving/sending SMS using different provider)
>
> ~ 80 Watt
>
That's 340 Watts. Would it not use less power to consolodate that?
Perhaps the individual CPUs don't use much power, but each of those
boxes with the drives do. If it is truely better to have multiple small
CPUs instead of one more capable one, I would consider if it would save
power to use fewer drives and share space via NFS.
>
> Note: But this is ONLY for my MAIN Mobil-Office. My current computers
> for this configuration are eating OVER 1400W. = 1 kWatt to much!
>
> The other Mobile-Homes/Offices will have only:
>
> A) Router
> ??? (maybe ARM9 based but not found the right mainboard currently)
> 256 GByte memory
> SanDisk Ultra II 1 GByte
> 4 x MiniPCI Atheros WiFi 802.11a (5Ghz)
> 1 x NIC 10/100 MBit
>
> ~ 30 Watt
>
> B) Workstation
> VIA EPIA LN10000EAG
> 1 GByte memory
> SanDisk Ultra II 2 GByte
>
> ~ 20 Watt
>
> where I have this ensemble 7 times.
>
>
> Thanks, Greetings and nice Day
> Michelle Konzack
> Systemadministrator
> 24V Electronic Engineer
> Tamay Dogan Network
> Debian GNU/Linux Consultant
>
>
> --
> Linux-User #280138 with the Linux Counter, http://counter.li.org/
> ##################### Debian GNU/Linux Consultant #####################
> Michelle Konzack Apt. 917 ICQ #328449886
> +49/177/9351947 50, rue de Soultz MSN LinuxMichi
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