RE: PE1950 - EnergySmart - any disadvantages?
michalwd1979 at o2.pl
Mon Oct 15 23:38:43 CDT 2007
Thanks for the info Faris.
From my test it turns out that the efficiency of PSU is rather poor. 1 PSU of dell2850 takes about 40-50W idle. In my configuration no loaded server uses 180W (3 SCSI drives 2x 3GHz Xeon, 4G RAM). Fully loaded it needs 240-250W. In fact I could save about 40W just by taking out one PSU. Some other problem is cooling system. 6 high speed fans can take 70-80W alone when running on full speed, much less when running on reduced speed.
I am using water cooling and only one PSU so I saved about 100W (0.4A). Now we are strongly thinking about making custom DC-DC PSU that will run directly form 24V battery, thus we will not need UPS, that alone can take some power just to covert energy 2 times. The problem is the connector to main board, I need to get documentation somewhere.
The server works in __VERY__ small private electronic company, we bough it used (without warranty) so we can play with it. My luck.
> Michael, I don't know the true power consumption. I only know what the Dell calculator says. > Basically the PE1950 in standard config with the drives and CPUs mentioned above, plus 8Gigs > of Ram (4x2Gb) is 1.58 Amps. In the EnergySmart config the Dell calculator says it would > take 1.32Amps.
> That's still a heck of a lot more than our PE1550 and our now defunct PE1650 (which blew up > quite nastily when out of warranty but that's another story and Dell sorted us out > *supremely well* so I have no complaints other than the two days with no sleep that were the result). I don't think either of those go over 0.7A. I find that very annoying. I'd have thought that PSUs, for example, would be more energy efficient in this generation that one from many moons ago. But those machines had 1Gig PIIIs in them, and no more than 1Gb of Ram. And only 3x36Gb 15k SCSI drives but I'd have assumed those took far more power than the 2.5in 10k ones.
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