Joe Ippolito's Home Page


A “negawatts” operation:

I wanted to save space and see how much I could reduce the power consumption on my W2K8 server that runs 7x24 at home. I moved it from a 4U to a 2U rack-mount chassis, added a passive CPU cooler and three PWM 80mm fans. This is an Intel Core 2 E7300 with 4GB PC2-8500 1066 MHz RAM, Seagate 1 TB HDD Server running AD, DNS, Web and FTP servers. Power at idle is less than 37-38 Watts according to the Wattmeter on an APC UPS. 37-38 Watts includes a Motorola cable modem, Linksys voice router and a Panasonic wireless phone adaptor.


The 7200 rpm Seagate ST31000340AS 7200.11 drive is not as efficient as the Western Digital 5400 rpm Green TB drives. The higher rotational speed of the Seagate provides better data rates though. Seagate’s newer TB drive (7200.12) uses 2 500 GB platters instead of 3 340 GB platters. Higher density, fewer heads get a higher claimed sustained data rate at 160 MBps maximum instead of 105 MBps. A March 2008 review of TB drives can be found at,2845,2274993,00.asp .


The power supply is an Antec Earthwatts 380W 80 PLUS Certified. Motherboard is an Intel DG45ID that meets the ENERGY STAR Category B requirements. The Intel on-board video runs 32” 1080p monitor at native resolution and 32-bit color with additional power of course.


I is unfortunate that Intel disabled Jumbo Frames out of the DG45ID Imbedded GigE as default. I am trying to figure out how to correct that.


Here is what the baffles and three Arctic PWM fans look like.




It was a challenge getting the Intel BIOS to see fan speed for each of the three fans but they all run at 600-700 rpm and the whole thing is extremely quiet. They are capable of up to 2000 rpm. CPU runs really cool but ICH and MCH are still warm.




Baffles are made from 24oz aluminum cans. Note the square I cut out of the rear drive tray to get airflow from the passive CPU cooler. The tray could still be used for drives if needed later.




Punch out for fan at rear was very restrictive and was unfortunately larger that the 80mm fan. I cut an 80mm hole with a Bosch bimetal hole saw. Grills are $2.99 a pair at Fry’s. Fan openings in the fan wall were much too restrictive also (below).




I also cut 80mm holes for the fans in the wall. Note baffle covering openings in fan wall below.




I recommended to the case manufacturer that they add punch outs for the two fans and reduce the wire path to a small relief at the bottom of the wall. The wall could also use a couple more screws, one on the side and one on the bottom.


Junior Solar Sprint


Developing Battery Technology