Jed Clear wrote: > On Sun Feb 28 9:00 , Henrik /KaarPoSoft sent: > > >>>> Dear all, >>>> >>>> I have a net5501, which seems to work with a Kingston 64GB SSDnowV+ >>>> (SATA) and Seagate Barracuda 7200.7 (3.5" 160GB) SATA. >>>> However, I can not get it to work with my Seagate Barracuda ES SATA >>>> 3.0Gb/s 750-GB Hard Drive (ST3750640NS). >>>> >>>> The 750G Barracuda has worked fine for a year in my Dell PowerEdge T105, >>>> and I put FreeBSD 8.0 on it using my Dell OptiPlex 8400, where it also >>>> works fine. >>>> >>>> However, when I put the 750G Barracuda in the net5501, it does not get >>>> past POST. >>>> Most of the time I get to >>>> POST 0123456789bcefgh >>>> sometimes to >>>> POST 0123456789bcefghip >>>> and sometimes it even starts to check memory, but does not get past the >>>> 0000 Mbyte >>>> >>>> Once it acutally got past POST and into the ComBIOS, but the drive still >>>> not visible. >>>> >>>> >>> This, to me, suggests a power issue. When my Soekris supplied wall warts >>> started >>> to go, I'd get behavior like that on my 5501 with just a CF card. Assuming >>> you're powering the drive through the Soekris and it draws more power than >>> the >>> other two drives, it could be you're over taxing the power supply. You >>> could try >>> an experiment and try to find a way to power the drive externally. >>> >>> >>> >> Hi Jed, >> >> Thanks for the suggestion! >> >> I am an absolute newbee on embedded and power issues ))-: >> >> According to the specs the SSD will draw 3.5 -4.2 Watts on operation. >> The Barracuda 7200.7 160Gb (which works) draws 12 Watts average on >> operation according to spec. >> The Barracuda ES 750Gb (which does not work) draws 13 Watts average on >> operation according to spec. >> However, according to specs both the Barracudas draw up to 2.8 amps on >> 12V, i.e. a mighty 33.6 Watts on spinup. >> So I guess the problem could be that the voltage is dropping during spinup. >> >> Everything is powered through a 12V, 1.5A C8 power supply (supplied by >> Cortex); i.e. 18 Watts. >> >> I have searched the Soekris specs, but I cannot figure out how much >> power the net5501 itself needs, neither how much power it can supply to >> the SATA disk. >> > > I think this was discussed on the list a little while ago. Maybe it got > captured > on the wiki, but it should be in the list archives. And that may have been > one > of those times Soren made a definitive statement. > > >> Would it make sense to purchase another external power supply (e.g. 12V, >> 3A), or does the Soekris net5501 internally limit the possible power to >> the SATA disk, now matter what the external power supply can deliver? >> > > I'd think that would be the next thing to try, assuming someone else doesn't > come > up with a definitive alternative solution. Obviously there are practical > limits > to the current going through the net5501, e.g. I'd think 200A might tend to > convert circuit traces into blown fuses. And the net5501 web page does > mention a > 20W limit on the external DC input to the 5501. > > >> (I don't think I want to experiment with powering the drive "externally") >> > > You could use the PC you built it on as a power supply, being careful with > grounding. Borrowing an external disk enclosure would be better if that's an > option. > > > Dear Joel and Jed.
Thank you very much for your input! When I purchased the net5501 I was aware of the limitations of CPU and RAM, but it seems I was an ignorant when it comes to power a harddisk ))-: The whole point of this "project" is to have a box I can store away in a corner, so an external power supply for the disk is *NOT* and option for me. I think I might purchase a disk that will fit the net5501. But I have not found any statements on power maxima in the list archives I checked. Not being able to use a disk I found in the basement is OK, but I certainly would not like to purchase another disk, just to run into the same problem. So: Can anyone advice me as to the max power specs of a drive that will work with the net5501 ? /Henrik _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
