[LINK] Green web servers with netbook components

[Tom Worthington]

Last week Sean Casey from Intel talked to the ACS Victorian Branch 
Green IT conference about Intel power saving CPUs. At the time it 
stuck me as interesting that one chip he did not mention was the 
Intel Atom. This is used for NetBooks and NetTops: cheap, low power 
notebook and desktop computers. It appears that Intel would rather 
you bought a more expensive higher power chip than the little Atom. 
It looks like that strategy is not going to work, as according to 
media reports Dell will use the same type of low-power processors 
used in netbooks for its XS11-VX8 server: 
<http://www.cio.de/news/cio_worldnews/885260/>.

The Dell XS11-VX8 server will use Via's U2250 1.3GHz "Nano" 
processor, which is a competitor to Intel's Atom. This is intended 
for Web hosting applications which do not need CPU intensive 
computations. It may spark a new market in low power, low cost 
servers both in small business and for large capacity green data centers.

The conventional thinking on servers has been high density 
specialization: pack as much processing capacity as possible onto a 
processing server and disk capacity into a data server and then try 
to load share it efficiently. Dell's approach is similar to that used 
for Google's servers, where each disk gets its own processing 
<http://www.tomw.net.au/blog/2009/04/google-battery-backed-shipping.html>.

The 2U rack mount case of the Dell XS11-VX8 will hold up to 12 server 
boards. Each board has one Nano processor, up to 3GB of RAM, a 2.5 
inch disk (or flash RAM equivalent), a SD card slot for boot software 
and two Gigabit Ethernet ports.

This approach opens up the server market to companies which make PC 
motherboards. There is the possibility for further simplification and 
cost reduction in design. The Dell design still looks over engineered 
compared to Google's servers. Dell use metal brackets and a front 
panel on its server modules. Google use Velcro to hold some 
components on its server and flying leads.

This approach could be applied to server modules, which could consist 
of bare circuit boards, with the connectors soldered on (no metal 
cabinet). The disk drives could be held on with Velcro. The modules 
could be held in a Eurocard type of rack, but with no back plane 
connectors, just plug in cables on the boards 
<http://en.wikipedia.org/wiki/Eurocard_%28printed_circuit_board%29>.

Server densities have got a little silly, with ultra high density 
servers requiring so much power and cooling that most data centers 
cannot accommodate them. Also the amount of air which has to be 
pumped through the servers increases the power consumption and makes 
them dangerous to stand near, due to the noise.

Instead low cost web servers could be designed to have generous 
spacing between the components. This would allow cooling with few 
fans (or no fans when installed in a "hot isle" rack). These low 
power servers could be placed in racks between the high power 
servers, in the slots which current have to be left blank, to avoid 
overloading the cooling and power systems.

For very small scale applications one server board could be held in a 
snap together plastic clamshell case. Large servers do not really 
need a case at all, relying on the rack mount cabinet.



Tom Worthington FACS HLM tom.worthington at tomw.net.au Ph: 0419 496150
Director, Tomw Communications Pty Ltd            ABN: 17 088 714 309
PO Box 13, Belconnen ACT 2617                      http://www.tomw.net.au/
Adjunct Senior Lecturer, Australian National University