By: Henrik S (henrik.stahl.delete@this.oracle.nospam.nothanks.com), November 10, 2008 10:48 am
Room: Moderated Discussions
>>>>The best L5420 score with JRockit (from NEC) is *much* higher: 1010 ssj_ops/watt
>>>>http://www.spec.org/power_ssj2008/results/res2008q3/power_ssj2008-20080714-00064.html
>>>
>>Supermicro result here for reference:
>>http://www.spec.org/power_ssj2008/results/res2008q4/power_ssj2008-20080917-00079.html
>
>There is rather small 3.3% difference in favor of NEC.
>Could it be explained by better tuning (different compiler options, in particular,
>-XXlargePages, bigger initial heap) and smarter configuration (disabling unused NIC)?
3.3% is almost so small as to be irrelevant. Run-to-run variation on jbb is ~2%, to give some perspective.
-XXlargepages is implied by -XXaggressive so no difference there (we are trying to kill the -XXaggressive flag so we encourage OEMs to specify -XXlargEpages etc explicitly).
The heap size diff makes a small difference, but probably not more than ~1% in NEC's favor.
The rest is probably BIOS and HW. But the results are so close that I would guess that the HW setups are near-identical.
-- Henrik
>>>>http://www.spec.org/power_ssj2008/results/res2008q3/power_ssj2008-20080714-00064.html
>>>
>>Supermicro result here for reference:
>>http://www.spec.org/power_ssj2008/results/res2008q4/power_ssj2008-20080917-00079.html
>
>There is rather small 3.3% difference in favor of NEC.
>Could it be explained by better tuning (different compiler options, in particular,
>-XXlargePages, bigger initial heap) and smarter configuration (disabling unused NIC)?
3.3% is almost so small as to be irrelevant. Run-to-run variation on jbb is ~2%, to give some perspective.
-XXlargepages is implied by -XXaggressive so no difference there (we are trying to kill the -XXaggressive flag so we encourage OEMs to specify -XXlargEpages etc explicitly).
The heap size diff makes a small difference, but probably not more than ~1% in NEC's favor.
The rest is probably BIOS and HW. But the results are so close that I would guess that the HW setups are near-identical.
-- Henrik
