> 4GB RAM

[Tom Metro]

[Sorry about the last message that had only quoted text. I apparently 
hit on a keyboard shortcut in Thunderbird (Ctrl-Enter) that I wasn't 
aware of that immediately sends the message.]

Jarod Wilson wrote:
> The only laptop I *know* supports more than 4GB are the latest MacBook
> Pros...

I haven't specifically looked for such machines yet, but I ran across 
the HP DV7-1020US[1], which claims (at least on one retailer's site) to 
support a maximum of 8 GB.

The problem with that HP model compared to the Acer (AS8930-6306[2]) I 
was looking at is that it has a slower CPU, slower hard drive, a smaller 
screen, and lower resolution, while costing about $50 more. The price 
difference is irrelevant, but the feature differences may not be.

What I'm pondering is whether the ability to double the RAM in the 
future is a better long term advantage than having slightly faster CPU 
and RAM.

Similarly there is a pair of Toshibas in this class, G55-Q804[3] and 
X305-Q705[4]. The G55-Q804 has the same screen size and resolution, but 
slower CPU, RAM, and hard drive. The gamer optimized X305-Q705, aside 
from being red, has higher-end graphics, comparable RAM and hard drive, 
but slower CPU, and a smaller screen. Neither claim support for more 
than 4 GB RAM.

All of these machines are at least partially aimed at gamers, so they 
all have higher-end graphics controllers, varying from the
NVIDIA GeForce 9200M GS w/256 MB (G55-Q804) to the NVIDIA GeForce 9600M 
GT with 512MB (Acer, HP) to the NVIDIA GeForce 9700M GTS (X305-Q705), 
but graphics performance is fairly irrelevant for the intended 
application. (I see Toshiba has a Q706 variation of the X305 family that 
has the same CPU as the Acer, and otherwise seems the same as the Q705, 
but has a 9400M and two 9800M graphics controllers for $700 more, and 
thus is out of this price class.)

Similarly some of these include Blu-Ray optical drives and some don't 
and I haven't paid much attention to that as it is also irrelevant.

1. http://www.circuitcity.com/rpsm/oid/215032/rpem/ccd/productDetail.do
2. 
http://www.newegg.com/Product/Product.aspx?Item=N82E16834115507&cm_sp=MyNewegg-_-RctViewDC-_-Pst02Descrip
3. 
http://www.bestbuy.com/site/olspage.jsp?skuId=9064335&st=toshiba+17"&lp=5&type=product&cp=1&id=1218014503463
4. 
http://www.bestbuy.com/site/olspage.jsp?skuId=9036483&st=toshiba+17"&lp=4&type=product&cp=1&id=1218011399812


> ...theoretically, any laptop with the same chipset should be able to
> support the same...

That's what I figured. Though it is still a gamble, as it may be 
dependent on the BIOS, which may or may not get updated in competing models.


> Heavy virt is about the only reason I'd need more than 4GB for a laptop.

And jay-R5TnC2l8y5lBDgjK7y7TUQ at public.gmane.org wrote:
> It will be useful for the memory intensive programs such as vm,
> video, 3d rendering ect.  Also even if the program itself doesn't
> support more the os will so multitasking will benefit.

OK, but is using > 4GB, even spread across multiple applications (some 
of which may be VM hosts), dependent on the base OS being 64-bit?


> However on a laptop the question is will the cpu and bus limit you to
> the point of making it worthless. I'm not really up on the current
> laptop options but unless its a decent desktop replacement or a
> gaming system I would guess cpu and bus will be your limiting factor.

While the CPU on these machines is about comparable to a midrange 
desktop CPU of two years ago (according to the benchmark charts), all 
the machines I'm looking at have a 1066 MHz front side bus, 3 MB L2 
cache, and DDR2 RAM (DDR3 in the case of the Acer and Toshiba X305-Q705).


> Also I wouldn't consider a system that doesn't have good
> documentation.  You can try and dig up the answers but with all the
> competion is it worth it?

Not if the competition is actually any better. I'll take a look, but I'm 
not expecting to find much differences in the quality of the 
documentation from the other models.

There are always outlier exceptions, but on average I've seen little to 
distinguish laptop brands in recent years. They all have similar build 
and reliability reports (most being made in a few common factories), 
load their machines with junk software, omit OS install media, and lousy 
tech support.

Taking a look, HP does get credit for clearly listing the maximum memory 
capacity in their specifications...although that depends on which page 
you look at. Here:
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01496283&lc=en&dlc=en&cc=us&product=3754328

it lists the typical single memory spec. with no indication of max 
capacity. Here:
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01509826&cc=us&dlc=en&lc=en&jumpid=reg_R1002_USEN

it has both max and what's shipped.

Like the Acer, the manual has generic information. Actually, HP provides 
a separate document describing the mechanics of swapping memory modules. 
The manual also covers the same ground more briefly, but confusingly 
depicts the machine as having only one memory slot, and lists HP memory 
part numbers for 512 MB, 1 GB, and 2 GB modules. So this is obsolete for 
a machine shipped with 4 GB, or an inaccurate indication of the number 
of slots (must be the latter - the chipset is designed for two slots).

The HP documentation really goes into minutia - detailing the individual 
pinout of every connector, the I/O memory map of every product 
variation, and even charts for every type of screw. Fortunately it also 
lists some useful information, like the chipset (Intel PM45), though I 
don't have high confidence that it is not obsolete. The CPUs listed in 
the same chart are all obsolete, though chipsets change less frequently. 
(Adding to the confusion the manual covers both AMD and Intel-based 
products, which are essentially different platforms, even though they 
are part of the same product family.)

Third party sites say the Acer also uses the PM45[1], and Intel's spec 
sheet[2] shows it supports up to 8 GB of DDR3 RAM (in two double-sided 
SODIMMs). So there's a good chance the Acer supports 8 GB as sold. I ran 
across a thread[3] speculating on whether the Acer supports greater than 
4 GB, which didn't come to any conclusions, but suggested that the spec 
listed only 4 GB due to OS limitations or because larger modules weren't 
available at the time the specs were written.

1. http://forum.notebookreview.com/showthread.php?t=307521
2. http://www.intel.com/Assets/PDF/datasheet/320122.pdf
3. http://forum.notebookreview.com/showthread.php?t=312317

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/