Compaq ProLiant DL360 Ultra-Dense Server Deployment in Compaq Racks

Compaq ProLiant DL360 Ultra-Dense Server Deployment in Compaq Racks 20
128H-1100B-WWEN
2.2.3 Input Power Budget De-rating
If a deployment plan limits the future expansion beyond certain configurations, then adjustments
may be made to the input current and thermal requirements based on the worst-case configuration
for a specific site deployment.
This section explains how to de-rate the input power budget. Assume that the power supply rated
input power of 292W is for the “maximum” configuration. For initial availability of
ProLiant DL360, the maximum configuration (with remote console management) can be assumed
to be as follows:
2x933 MHz, 4x1 GB, 2x18.4 GB, SA5300, Remote Insight Lights-Out Edition
The peak input power of a subsystem/component is added to or subtracted from the rated (peak)
input power when the subsystem is added or removed, respectively. When a subsystem is added
to a configuration, either the typical or the peak input power of the subsystem will be added
depending on whether the server input power budget or the thermal dissipation is to be calculated.
Following are some rules of thumb for calculating the power budget and the thermal dissipation
for both methods when a subsystem is added:
1. To calculate the power budget, the peak power should be added.
2. To calculate thermal dissipation, the typical power should be added for the hard disk drives
and peak power should be added for all other components.
3. To calculate either the power budget or the thermal dissipation, only the typical input power
should be added when the 2
nd
drive is added. Typical input power is listed in
4. Table 2-4. The reasons for this suggestion are:
• The peak input power for each drive is for the beginning of the spin-up duration, which is
relatively short, for example, 10 seconds. During normal operation, that is, while an
application is running, the power consumption of a disk drive varies.
• The drives are spinning up at different times. Therefore, only one drive will consume
“peak” power at a time within a server. Note that the only time that up to 42 drives can be
spinning up simultaneously in a 42U rack is if all the servers regain power
simultaneously, after having lost power. Then all of them will restart automatically and
almost simultaneously.
• There is almost no activity in the processors or memory DIMMs when the drives are
spinning up.
Example
Assuming the desired server configuration is 1x550 MHz, 2x128 MB, 2x18.4 GB
The rated input power for the ProLiant DL360 power supply is 292W. Therefore, the power
budget for a maximum configuration is 292W, and the thermal dissipation will be approximately
(292*3.41=) 996 BTUs/hour.
After removing the 4x1GB DIMMs, 1x933MHz processors, the SA5300 and the Remote Insight
Lights-Out Edition from the maximum configuration:
The peak input power of the server will be (292-(4*5)-(1*30)-15-16) = 211W. Since we used
the 933MHz processor’s input power instead of the 550MHz processor's, the 211W is a more
conservative number.