Amount of Ram

[el_sr_al]

Hi,
I'm about to buy a new laptop and I have the option of choosing the amount of SDRam that I can buy with it.
The Laptop is a fujitsu S6010 with PIII 1gh processor, and 40GB Hard disk drive, running windows XP professional.
It comes with a minimun of 256mb of Sdram and it can load upto 1gb of Sdram in two modules of 512Mb. I was thinking of buying it with 512Mb in two modules of 256 as it is the best prize/amountofmemory ratio of them all. But I have the following questions that I would really appreciate if anybody could give some answers to:

-Is there a difference in performance if the same amount of memory is in one module or divided into 2 modules?

-Second and most important one: I use my laptop basically for Video encoding (divx) and Mpeg2 transport Systems editing from Sony's Ip7 camcorder, Would it make a difference if a load the laptop with 512Mb vs 768 or even 1Gb in terms of performance? Or is there an optimal amount that from that on the difference won't be worth it in relation to the expediture?

Thanks
El_Sr_Al

PS:Before anybody replies buy a desktop, that's not an option at the moment.
Second I know usually the more the better, but I'm looking for the optimal amount.

[The Edge]

I did a benchmark in work to find out a while back. Sometime last year
Setup:
Athlon@1400, sdram pc133(256*3), WinXP
At 256mb, we got 19fps(all approx)
At 512mb, we got 27fps
At 768mb, we got 29fps.

So i think after 512 of memory, not much to gain.
I think FSB is more important e.g DDR333 or DDR400 or Rambus etc.
hope this helps.

(Note. I think it was flask we were using at the time)

[theReal]

I can't believe you got a 2 fps improvement with 768MB over 512MB.
How much other stuff was running on your machine along with the test?

I have 512MB of RAM in Win2k and I'm never able to fill the RAM with video encoding tasks - although I have disabled the paging executive and set the IOPageLockLimit to 64MB in the registry (which is only 512k per default).
I've never seen any video-encoding task use more than 250MB of RAM (and that was with the help of an older version of avisynth, the newer versions take less). So, if your RAM usage without video editing is not always more than 256MB, 512MB should be plenty.