Emax Drive power readings
2009-08-25 by Ted Summers
So I have heard it many times that internal Zip drives take too much power and will cause the Power Supply to fail. I am thinking this is bollocks. So it was time to do my own little episode of Myth-Busters. Well- I have in my possession: Internal Zip 100MB Drive Miniscribe 8425 20MB Drive Conner CP3040A PCD-50 and MicroTech DPAI-SCSI PCMCIA drives So, to put this to rest once and for all I rigged up: Ampmeter on 5v and 12v power rails and I measured the drives several times to come up with some average numbers. Peak is highest value hit ever, and occurs on first power on. Here is the comparison..... 12v Amps 12v Amps 12v Amps 12v Amps 5v Amps 5v Amps 5v Amps 5v Amps Drive Description Peak Load (r/w) Idle Label Rating Peak Load (r/w) Idle Label Rating Miniscrbe 8425SA � Full Height 1.12 0.86 0.86 0.9 0.6 0.58 0.56 0.9 OEM equipment for Emax If I am incorrect, someone let me know Conner CP3040A � Half Height 0.56 0.52 0.12 0.25 0.51 0.5 0.4 0.28 Zip 100MB -Internal 0 0 0 None 0.58 0.43 0.41 0.8 SCM PCD-50B PCMCIA / CF adapter 0 0 0 None 0.58 0.54 0.21 1.5 As we can see from my readings, the Label Rating may or may not be accurate - look at the Conner.... Is that an average of the load and idle numbers on the label for the 12V??? :-) But we can see from my tests that the Miniscribe would be hardest on the power supply and has the highest power consumption..... We can see that from my tests the 5v power distribution is no harder hit by a Zip or PC Card drive than the original Miniscribe, and once into idle mode after data read, is lower by an obvious margin. Additionally, they completely remove any load that occurs on the 12V power rail. Your Mileage May Vary, but from what I can see, neither internal Zip or PC Card drive is a bad option. Regards, Ted [Non-text portions of this message have been removed]