Flying Fox wrote:Also needs to be considered are the latest fashion trend, the bling bling LED lights, flouresent tubes and such. A few more watts here and there, but it shouldn't detract from the main idea that you don't need 1000W.
Flying Fox wrote:Usacomp2k3 wrote:What about my watercooling?
It depends on where are you powering that from of course. Your minigate is off the main PSU, so it is something else to be considered. But you already know that, right?
Flying Fox wrote:It's all about headroom, not just for expansion, but for device startup as well. The HDs and optical drives are mechanical devices and will take more wattage to power up when you turn it on. Not sure how many more watts you need to tag on in order to make the formula work, but it is true that we are talking quality not quantity here. Also, USB powered devices can also draw a couple of amps too.
Let's hope staggered spinup will be implemented soon on more HDs so we don't have that huge power draw.
MFN: DF128025SL-4 23.12 CFM, 27.07 dBA, sleeve bearing 20K hour MTBF@25°C, 18 inch power leads, 4pin power connector, includes mounting screws
Unit Price: $0.85
Uses 1.68 watts each. I normally use 80mm fans because I have them on hand for computers, also they are cheaper each and use less power each. I think the 120mm I looked at was around 5 watts.
computron9000 wrote:AFAIK hard drive spin-up can't require more than the PEAK LOAD values I supplied.
A drive can't work harder than it works at its hardest? hehe All values supplied are PEAK / MAX LOAD values. If they were idle values, assume nearly 50% of what I stated overall. I guess it depends on whether the watts to maintain spin and move the head are greater than power needs to get up to final speed?
just brew it! wrote:I'm having a hard time finding peak current draw info for the Raptor. But the Seagate 7200.9 is speced for a peak draw of 2.8 amps from the +12V rail during spinup, which is nearly 34W!
Captain Ned wrote:Flying Fox wrote:We sorely need staggered spinups, like yesterday.
Has the SATA specification allowed for this like SCSI has done for eons?
CampinCarl wrote:So, pardon the newb question, but:
What exactly are the 3.3v and 5v rails for these days?
However, if we look closer we find 12V1 is doing 10A while 12V2 is doing 15A. If the X2 is on rail 1 coupled with a hard drive (or 2), will that be too close for comfort?
What the above means is that you don't need to worry about imbalances in power draw on the 12V lines �as long as no single line is asked to deliver more than 20A. PSU makers seem to mark each line for max current on a purely arbitrary basis, probably more for marketing reasons than any other. A PSU rated for 32A max on the 12V lines can be labelled many different ways:
* 12V1: 18A, 12V2: 14A
* 12V1: 17A, 12V2: 15A
* 12V1: 16A, 12V2: 16A
* 12V1: 15A, 12V2: 17A
* 12V1: 14A, 12V2: 18A
It could be marked 20A + 12A, but being a cautious bunch, the engineers will probably not specify more than 18A on any one line. This gives 2A headroom to allow some room for error for the current limiting circuit.
Intel ATX12V v2.2 guide:
-- In cases where expected current requirements is greater than 18A a second 12 V rail should be made available. (18x12=216VA, to allow peak headroom to 240VA)
-- 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.
-- 12V1DC and 12V2DC should have separate current limit circuits to meet 240VA safety requirements.
-- 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
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