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Posted Dec 22, 2005 11:59 UTC (Thu) by rrw (guest, #9757)
In reply to: User base by ringerc
Parent article: SMP alternatives

A dual core system is essentially SMP... and laptops are very power / performance concious. It would not hurt in the slightest to eke out every bit of speed (or efficiency, ie potentially less power use) while on a half-clocked single-core CPU for battery saving, then safely switch to full-bore dual-core mode when on mains.

OK, I have a problem with this. Why would I need to clock down a notebook on batteries and clock it up on mains?

When a Centrino notebook on mains works with full speed it soon gets so hot that the fan works non stop, and the keyboard itself gets annoyingly warm.

On the other hand, when notebook runs on battery and I want to do something cpu intensive it is painstakingly slow. But where's the power consumption advantage? I have to do this anyway, slower or faster, and if I do something with downclocked CPU, power consumption per unit of time in display, gpu, harddisk doesn't decrease, so I actually eat more juice.

Isn't it better to just use sth like powernowd, which dynamically clocks processor depending on system load, wheather you use mains or battery?

Robert


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CPU usage optimisation

Posted Mar 30, 2006 5:20 UTC (Thu) by xoddam (subscriber, #2322) [Link]

Exactly. The CPU configuration and speed should be adjusted according to
demand for processing power, not supply of electricity.

There is never a case for consuming more power just because you *can*.
Otherwise we'd all leave all our computers and all our lights switched on
all of the time. Bring on global warming.

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