Image Map Image Map
Results 1 to 6 of 6

Thread: PSU efficiency ratings for the IBM PC and XT power supplies? 63/120 watt versions

  1. #1

    Default PSU efficiency ratings for the IBM PC and XT power supplies? 63/120 watt versions

    Does anyone know what the efficiency of the older IBM 5150/5160/5170 power supplies are, and what they would translate to in today's power supply ratings?
    I have a Major in Post-Apocalyptic Economics.
    Wanted: Any PC-Compatible Reciprocation Dingle Arm

  2. #2

    Default

    At best 65%. SMPS were about 60/65 for ages. Probably with a power factor of about 0.65 as well.

    In other words, awful.

  3. #3
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    34,141
    Blog Entries
    18

    Default

    You could test it yourself with a dummy load of known characteristics and a Kill-A-Watt.

    My recollection is that PFs on these things were really awful.

  4. #4

    Default

    Since they run below their rated value, most of the time, their efficiency may be even lower.
    Dwight

  5. #5

    Default

    Regulation on this came far too late IMO.

    HP and Iím sure all the others were still selling servers with 65% efficient PSUs as late as 2010. The sheer waste in data centres is almost incomprehensible.

  6. #6
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    34,141
    Blog Entries
    18

    Default

    It's a matter of perspective. Compared to the old linear-with-transformer PSUs, the switchers were ahead in efficiency, not to mention sheer weight. I can recall seeing a pile of 5V 200A SMPSUs for sale at Halted and saying to myself "You've got to be kidding--a 200 amp power supply in that little case?". So perhaps we were blinded.

    After all, it wasn't that many years prior that the power supply for much big iron was MG sets providing 400Hz 3-phase power. SMPSU design was a black art, according to comments I remember from Bob Boschert.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •