Dell POWEREDGE R720 - Manual (Page 13)

Power Efficiency Comparison of the Dell PowerEdge R720 and HP ProLiant DL380p Gen8 Rack Servers
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The following JVM options were used on both servers, as they are the best-known JVM tunings for
SPECpower_ssj2008 for the IBM J9 JVM:
-Xms1024m -Xmx1024m-Xmn853m -Xaggressive -Xcompressedrefs -XlockReservation -Xnoloa
-XtlhPrefetch -Xlp -Xgcpolicy:gencon
The following bindings were used to ensure that each of the sixteen JVMs ran on 2 logical processors:
start /affinity [3, C, 30, C0, 300, C00, 3000, C000, 30000, C0000, 300000, C00000,
3000000, C0000000, 30000000, C0000000]
Power and temperature configuration
We used the Yokogawa WT210 Digital Power Meter for the actual power measurement of the servers, as this is
the most commonly used analyzer for SPECpower_ssj2008 publications at the time that this study was
undertaken. The WT210 unit used was calibrated in October of 2011 to ensure accurate power consumption
measurements.
To ensure a fair comparison, the systems were mounted in the same rack, and inlet temperature was measured
at the front of both systems during their runs using a Digi International
Watchport/H temperature probe. As
the attached Power _Temperature Details reports show, the two systems were run in environments with a
temperature difference of less than 1 degree Celsius.