[Info-vax] The Future of Server Hardware?

[JF Mezei]

ChrisQ wrote:

> name. right ?. Googles "mainframes" have thousands of cpu boards, each of
> which need not be  particularly powerfull, nor draw much power and may be
> in hibernate mode or woken up as load varies, almost from query to query. A
> much more finely grained division of labour and energy management.
> 
> Of course, less cooling requirement must mean that the systems are also more
> power efficient as well, so there are gains all round. Air conn is very
> wastefull of energy...


The bragging about being green isn't so much about less cooling
requirement but rather more efficient cooling.  So the bragging doesn't
include reduction of electrical cost of running a gazillion servers and
the heat they generates. It focuses or more efficient heat extraction.

When you have a gazillion servers, you also have a gazillion power
supplies, and multiple gazillion fans always running in those servers.
While modern servers have the ability to vary fan speed based on heat in
CPU, there is still much of a waste with the "idle" machines still
running fans and still running a power supply.