[ltp] X60 - (bad) experience, others?

[Theodore Tso]

On Tue, Jan 29, 2008 at 07:41:48PM +0100, Nils Faerber wrote:
> > Lenovo gives you three possible batteries, plus the option of
> > attaching an 2nd, "extended life battery" to the bottom of the laptop,
> > connecting via the dock connector.  If you use the 8 cell battery plus
> > the extended life battery, you can get 11 hours of battery life.  :-)
> 
> Uh, sounds appealing but expensive ;)

Eh, with the US Dollar in the ditch, it's only a 100 Euro's each for
the 8 cell battery and extended life clip-on battery.  (Well, if you
have a friend carrying buying it in the US to evade the VAT and avoid
paying import duties.  :-)

> I basically found the guilty: uhci_hcd!
> The strange thing is that auto-suspend is enabled (and also on all
> devices) and that I did not have to remove it for getting 9.5W with
> 2.6.22. So something from 2.6.22 -> 2.6.24 changed in uhci_hcd and the
> change was not good, i.e. causing the CPU not entering C3 in 70-80%.
> Again, this was not necessary with 2.6.22...

Hmm, I've never had auto-suspend work well (or at least I never
trusted it), so I've always unloaded the USB drivers for maximum power
savings whenever I was in airplane mode; after all, in airplane mode I
don't really need anything connected to the USB bus, anyway.  So I
never noticed a problem, because I was always unloading uhci.

> He, if you can afford enough... if I pay 1100EUR for the laptop alone
> extra batterie_s_ quickly add up to a respectable sum. And since
> batteries have a limited lifetime (in contrast to the notebook itself)
> this should be considered very carefully.

Well, an extra battery is basically 100EUR, which is 10% of your
laptop, and yes, it only lasts about 2-3 years tops.  OTOH, having one
which you keep in the refridgerator except when you are on extended
trips, is not that bad.  Or just consider that an annual consumable
cost and not worry about it, which is how I tend to deal with the
issue.

> And while we are at batteries: I just also found that my X60 discharges
> the battery even when switched off!? Two days switched off eats almost
> 50% of the standard battery.
> Is that normal? If not I should probably check that more thoroughly and
> call Lenovo service :(

No, that's definitely not normal.  Have you checked to see whether it
does this only when the laptop is plugged into the laptop, or does it
also lose 50% of its charge when it's detached from the laptop?  It
could just be a bad battery....

> What I am wondering is why do companies like Intel always want to brag
> with MHz and GHz instead of adding a second line of really low-power
> optimized CPUs? The X31 I mentioned already had a 1.4GHz CPU with old
> technology and already quite power savy. Shouldn't it be possible to
> make a CPU with cutting edge technology (smaller processes, smarter
> architecture with more than one clock for different functional units -
> just as needed, independantly en- and disabling functional units, etc. I
> can live with a slower CPU if I do not get a lap heater and have longer
> battery life - 99.9% my CPU is idle anyway.

They do; it's called the LV (low voltage) line, and it's what is in my
X61s laptop.  The main reason why they don't do more is that there
simply isn't enough market demand for it, and most people still care
about performance benchmarks --- or at least, that's what most
magazine reviewers still tend to do, and it's what people pay
attention to.

They do care about battery time in terms of making the "battery
lifetime" as long as possible, but in practice that is only when the
CPU is completely shutdown.  So the general direction is to make CPU's
which do very well if they are completely not running, but also run
very quickly when they *are* running.  This is why it's important not
just to worry about the percent time in C3, but also the amount of
*time* spent in C3.  You really want to try to get the residency times
up to at least 35 milliseconds, and I've been told that in future
processor, it will be able to even more aggressive save power if the
processor can sleep longer.

						- Ted