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

[Theodore Tso]

On Tue, Jan 29, 2008 at 11:41:00AM +0100, Nils Faerber wrote:
> The standard battery that comes with it only lasts for 1.5h to max. 3h,
> but 3h means almost no CPU activity, backlight at lowest possible
> setting (almost unreadable) or off and all wireless turned off. If it
> shall be halfway usable the maximum I can get is 2.5h. Disappointing for
> a modern expensive mobile hardware - compare this to e.g. Apple's notebooks.

There's nothing magical here.  It's all about battery size.

Thinkpad X6x 4 cell slim line battery    28.8 Watt/hours (3 hours @ 9.3 W/hr)
Thinkpad X6x 4 cell cylindrical battery	 37.4 Watt/hours (4 hours @ 9.3 W/hr)
Thinkpad X6x 8 cell battery 		 74.8 Watt/hours (8 hours @ 9.3 W/hr)
Thinkpad X76x extended life battery   	 +28.1 Watt/hours (+3 hours @ 9.3 W/hr)

13.3-inch Macbook air (1.6Ghz)	      37 Watt/hours (5 hours @ 7.4 W/hr)
13.3-inch Macbook  (2.0Ghz)	      55 Watt/hours (6 hours @ 9.1 W/hr)
15-inch Macbook pro (2.4Ghz)   	      60 Watt/hours  (6 hours @ 10 W/hr)
17-inch Macbook pro (2.2Ghz)	      68 Watt/hours  (5.75 hours @ 11.8 W/hr)

The battery life times are taken from the Apple web site, and are the
standard marketing "up to" lifetimes.  The battery life times I've
quoted above is for my X61s, with backlight at 40%, and machine in
"airplane mode" (USB, wireless turned off, system configured in
laptop_mode, etc.) where I have my power consumption tuned down to 9.3
watts/hour.  If I take the backlight down to 10%, I can get it to 8.8
watts/hour, but that's not really a usuable configuration, where as
reading e-mail while on an airplane at 40% backlight and minimal disk
usage is at least a believable scenario.

The 4 cell "standard" battery is basically simply too lightweight for
what you want.  But in terms of actual power usage, the X60 series
aren't that much different from what Apple has; Apple is just simply
giving you a bigger battery --- and true to Steve Job's design
asthetic, he gives you only one choice. 

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.  :-)

BTW, the reason why the Macbook air can get 5 hours @ 7.4 W/hr is I
bet mostly because of the slower processor and the Solid State Disk
option (which costs a cool kilobuck more).  It also also skimps on a
lot of features (like extra USB ports, no wired ethernet, no parallel
ports, etc.)

Now, that's not to say that we can't do better; MacOS is much better
at automatically enabling low battery configurations where as I got
down to 9.3 W/hr by aggressively tuning my system.  But it's not like
the Apple hardware is fundamental superior; it's just software, and we
can fix software, since it's Open Source.  :-)

> The whole device is always quite warm, especially the region below the
> right handrest - I suspect that WiFi is sitting there because it gets
> even warmer when power saving on WiFi is not enabled or if it is used
> more intensively.

Yes, that's where the WiFi is.  You need to completely unload th WiFi
driver if you want the biggest battery savings, BTW.  I've already
complained to folks I know at Intel about this.

> The warmth also results in an ever spinning fan which is additionally
> also quite noisier than the ones in X23, X24 or X31 (which were almost
> inaudible at their lowest speed).

Faster processors means more heat.  :-)

Note that what some cheasy laptops will do is skimp on the fan, and
rely on the fact that the CPU will automatically throttle itself back
if it gets too warm.  So there are tricks you can play as a laptop
manufacturer that may look good, but then when you start running some
benchmarks, it's like... hey.... why is this laptop so much slower
than the rest even though it has the same rated speed CPU?

> The situation with Wifi drivers is not improving over the last 1/2 year.
> There is the IPW3945 driver which works quite fine but requires non open
> source parts and is difficult to install. The newer open source IWL3945
> does not work well (I have issues associating to APs) and I have the
> impression that its power saving is not that good too resulting in even
> less battery life. And since the release of 2.6.24 neither IPW nor IWL
> compile out of the box - heck, what's going on there? IPW will not get
> updated and there are third party projects to patch the latest IWL
> drivers for 2.6.24 - the IWL driver in the stock kernel 2.6.24 is at
> least three months old.

Yep.  Blame the intel driver folks.  I'm not sure what their
development methodology is, but their dev tree isn't well synched with
the mainline tree, for some reason that I've not been able to
determine.  This means that merging the latest IWL driver with the
latest kernel is not trivial.

> And while we are talking about 2.6.24 instead of getting better battery
> performance that was rumored to come with cpuidle I get up to 4W of
> battery drain - additionally. The lowest I can get with dim backlight
> and no Wifi on 2.6.22 is about 9.5W - with 2.6.24 it is about 13.5W. I
> found, using powerop, that one of the reasons might be that 2.6.22
> manages to keep the idle CPU in C3 for 95% of the time while 2.6.24 C3
> is only used for maybe 20-30%.

I have not seen a power usage regression on 2.6.24.  The power
utilization at idle for me is still around 9.3 Watts in my "airplane
mail reading scenario".  I was in C3 98% of the time, with an average
residency in C3 of about 50ms. 

If you're not getting that, it's probably a matter of software
configuration issues.  Or, try suspending (to ram) and resuming the
laptop, which seems to synchronize the timers to increase the average
residency time.  See my blog entry here:

http://thunk.org/tytso/blog/2007/10/29/tip-o-the-hat-wag-o-the-finger-linux-power-savings-for-laptop-users/

... for more details.

> I hate to say it but I am not really satisfied with the device and if I
> would have a choice I would buy a used X31 instead of the X60. But at
> the time I bought it I had no choice and sellig it now would mean a very
> high loss - so I have to stick with it.

Note that an x31 has a slow-slow-slow hard drive.  But if you aren't
doing anything hard drive intensive, maybe it doesn't matter.

> But there is also light ;) The CPU performance is quite nice! Big
> compile jobs just fly by. But this is not my most used use-case -
> especially for a sub-notebook.
> When do you use a sub-notebook most? Hm?
> When you are travelling or at least when you are on-the-go. And this is
> exactly where you usually do not have power plugs around so my most
> important feature request is a decent battery life - way before high CPU
> throughput.

Well, I like having my environment on one laptop, and not have to move
files back and forth between a "desktop" and "laptop" computer.  And
unfortunately I fly enough that I want my laptop to be my primary
computing environment.  It helps that I mostly fly American Airlines,
which has power plugs available even in the Cattle-class seats, but my
main answer is just to bring more batteries with me.

> When I was at OLS last year the most important feature request of Intel
> people there was thermal management in the kernel - for sure, because
> their hardware is always over-heating! They presented a prototype
> hardware in the form factor of a PDA with their newest and latest
> low-power mobile CPU - wow. Guess what, it had a fan! Sorry, but this
> cannot be honestly state of the art in low power CPU design. 

The problem is the tradeoff between speed, power, and heat.  Sure, you
can get something like the Intel XScalre (aka arm) processor --- but
then you will have people complaining about how slow the machine will
be.

> Oh well...
> If you feel you have a great tip to save power and/or prevent heat
> dissipation on the X60 I would be glad if we could share those tips here ;)

See my blog entry (listed above) for a whole bunch of tips.

My suggestion to you would be to get a bigger battery --- I would go
for the 8 cell extended capapacity battery ($179 on the web, $143.20
if you can find an IBM/Lenovo employee to give you a discount code),
and the extended life battery ($179 on the web, $143.20 EPP
friends/family price), and just be happy.  Yeah, it's heavier, but
remember, an Apple MacBook with the 13.3 inch display is 5 pounds.

The x61 laptop is 2.73 pounds with the smallest battery (weighing 0.44
lbs).  The 8 cell battery weighs 1.05 pounds, so with the 8 cell
battery the x60 laptop weighs in at 3.3 pounds, and if you add the
extended life clip-on battery, it's another 0.82 pounds, for a total
eight of 4.1 pounds.  At that point, you can have a 3.3 pound laptop
with 8 hours of battey life, or a 4.1 pound laptop with an 11 hour
battery life.  And you can feel superior to the person in the next seat
over with a 5 pound Macbook laptop with only a 6 hour battery life.  :-)

Regards,

						- Ted