[ltp] X60 hardware questions (no C4 state, only 3015 out of 4096 GB)

[Richard Neill]

Henrique de Moraes Holschuh wrote:
> On Sun, 21 Jun 2009, Michael Gaber wrote:
>>> 2. Only 3015 MB of the 4096 MB of RAM is available to Linux.
>>> According to thinkwiki, this is because of "chipset limitations",
>>> but the BIOS does see it all. That puzzles me somewhat.
>> i think the bios simply reads what the chip tells it, which is 4G
>> but afaik you'll have bad luck with a *60 and using >3G Ram
> 
> 4GB of RAM using two 2GB modules will be faster, and draw more power.  But
> you still can use only 3GB.

Thanks. I think I now understand the issue - the 32-bit CPU can only 
address 4GB, so the chipset masks most of the 4th GB to make it 
available as PCI address space.

1. I gather that the intel graphics chip uses up to 224 MB of main RAM
for its own purposes. Is this part of the 3015 MB I can see, or part of 
the 1009 MB that I can't?

2. Allocating an entire GB for PCI space seems rather wasteful - can I 
reduce this?

3. How much power does the RAM actually take? Are we talking a few tens 
of milliwatts, or could I save a couple of watts by going down to 2 + 1 GB ?


Richard