Re: Power Consumption

Hello Chris,

Am 10.10.2020 um 01:23 schrieb Christopher J. Wager | 56K Projects <
cwager@xxxxxxxxxxxxxxx>:

Couple of things mostly lower consumption related, at present I have my

a single psu installed in my desk side Power5.

1) does installing and plugging in the Second PSU massively increase

power consumption?

Not massively, but since every PSU has some loss (to heat), it will
increase. To learn more about a precise measurement of losses (not related
to IBM):


https://translate.google.de/translate?sl=de&tl=en&u=https%3A%2F%2Fkb.pocnet.net%2Fwiki%2FHP_MSA60_Leistungsaufnahme


https://translate.google.de/translate?sl=de&tl=en&u=https%3A%2F%2Fkb.pocnet.net%2Fwiki%2FHP_MSA20_Leistungsaufnahme

2) how much power do these things pull approximately at idle load.

Switched Power Supplies vary a lot in circuitry, even if basic parts stay
the same: Rectifier, chopper transistor, high-frequency transformer,
rectifier(s) and some kind of control loop, overload, and sometimes
underload protection. Within these confines, there can be refinement
against losses, enhanced stability, etc. Losses can be compensated by not
using dampening resistors but more elaborated ways to recover energy from
overshoots, using more circuitry to enhance the control signal of the
chopper transistor, use low threshold voltage components instead of plain
silicium diodes always "eating up" 0.7V, use fast-recovery diodes as
secondary rectifier, use high-quality caps with low inner resistance to
lessen conversion of ripple current into heat, etc. Newer designs need to
adhere to regulatory specifications, being more efficient.

All in all, these are an awful lot of factors. It's hard to even make
rough estimates. You can only know by measuring.

3) when the box is in the Power Off state but plugged in and the service

processor running does this still draw a significant amount of power?

Yes. Measurements, I took myself (for rough comparization):

- 9117-520: ca. 30W,
- 9406-800: ca. 20W,
- 9406-S20: ca. 20W,
- 9401-150: ca. 8W.

I thought, I had measured the idle load (only a fan) of my #7116 expansion
unit attached to my 800, but I can't find where I noted that down.

4) should I just flip the power switch once at Power Off state or is

doing that routinely going to box my power supply.

Do it. It's not doing any harm, and you save a considerable amount of
power.

This box is at home hence the opting for not being in all the time.

The 9117-520 I once had was drawing 600W from mains, with only one disk
attached. It generated an awful lot of heat and noise. Too much for me to
even run it occasionally.

:wq! PoC

PGP-Key: DDD3 4ABF 6413 38DE - https://www.pocnet.net/poc-key.asc


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