[LBo] Laptop for Linux - Gazelle Value

[Andrew Henry]

mars mr wrote:
> AND NO, if you have Dual CORE at 1,66 GHz you wont
> have same power as 1 processor at 3,2 GHz. 
>
> a second processor at the same speed give around 50%
> more processing power since it has to sincronize with
> the first processor.
>   
Where did you get this information from?  I do not think it is correct
but would like to read your source.  As far as I know, a dual core
processor package runs at the stated GHz speed (1.66 GHz in this case)
but there are 2 distinct cores within the package that split the
workload transparently for the applications--apps do not need to be
multicore aware to be able to use the chips features (this is still
true, despite what I write about processes and multi threading below). 
You wrongly refer to core #2 as a second processor and imply that core
#2 runs at 0.5x1.66GHz but this is not true either; the GHz rating
cannot be applied to a multicore chip to indicate how much work each
core can perform, it is simply a statement of how fast the electrical
signal is being sent to the physical processor, in this case, the
physical chip you plug into the motherboard can send signals across the
motherboard at 1.66GHz--a 'speed' rating that has been defunct for
several years now due to AMD releasing their Athlon line that gave a
comparative speed rating to indicate how fast the chip was compared to
Intels GHz rating on their chips, hence, and Athlon 3000+ is not
actually a 3GHz chip, but it performs the same workload in real world
testing as an Intel 3GHz chip.  If you notice, server chips that are the
best performers only run at 1.8GHz (Xeon/Opteron) whereas desktop
processors are hitting 4GHz, but the server processors are obviously
faster.  How much work each core does depends on the application...

An application specifically written for multi-core chips will perform
very well compared to those apps that aren't (I do not know of any
current consumer apps on the market written for multi-core chips, as
there are no multicore compilers yet, but i am not upto date either). 
When dual core came out, many hardware sites (SharkyExtreme/TomsHardware
et al) said that it would mostly be gamers/large scale computing
environments that benefited because gamers could run a game at full
speed, *and* run other apps at the same time with insignificant slowdown
in the game.  For office apps (at the time of release, but even now I
think) there was *no* benefit to dual core.  You needed a fully
multithreaded app like scientific/CAD/Engineering apps that could take
advantage of multicore chips.  If an app is not multithreaded the
process will only execute on one core.  In the gamer scenario, the
theory was that the game would start on one core, then additional apps
would start on second core as the processor had logic that would
determine that first core was under load.

But then again, it is late, and I have not checked *my* sources, and
like everyone else who posts to forums, I fully believe that I am 100%
correct :)  Please feel free to correct me if you know better.

One last word on Core2Duo...it is more battery friendly than AMD Turion
X2, all other considerations aside, so although I have traditionally
been an AMD fan, I choose Intel Core2Duo now because laptop battery life
is worth it's 'weight' in gold :)

As for the System76 laptop...it is a very nice spec. and the fact that
Linux is *guaranteed* to work is a definite plus.  In Sweden, we have a
deal through many employers where the government funds computers on a
36mnth repayment deal, and I just got a new laptop through this scheme
(so I pay much less than market price due to tax break).  I got an HP
Pavilion dv9297ea with Intel Core2Duo 7200, 2GB RAM, 2x160GB hard drives
and nVidia GeForce Go 7600 512MB.  I am very pleased with the build
quality of the HP compared to my older Acer Aspire laptop, which now
feels cheap and plastic in comparison.  Before buying your first laptop,
it is very hard to get a feeling for build quality, and this is one
point that the System76 laptop might fall down on, because the spec on
paper can look good for even the cheapest and nastiest laptop. 
Everything on the HP works with Ubuntu Feisty Fawn Herd 5 apart from
inbuilt webcam, which I do not care too much about.  My point is that it
is not at all impossible to buy a brand new laptop where all the
hardware works in a recent linux distro, but you have to do the research
first (especially regarding wireless adapter).  If you dont have the
time then System76 is a great option.

--andrew

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