Memory ??'s for Semi-Newbie

[TheGoatRyder]

Several questions here. I have read up quite a bit lately on the terms and stuff associated with basic memory problems. Here is my dilemma. I am currently running on a 256mb DDR PC2100 chip with an empty slot (Compaq Presario Notebook, 2 slots total), and am looking to improve performance through memory addition. I don't have a lot of money so I only want to buy 1 chip. From what I've read, I should stick with the same speed ie go with a PC2100 chip, but am not sure if I have to install a chip with the same memory as the one the computer came with, 256mb. Help with the following questions would be appreciated greatly:
1) Can I use a 512mb PC2100 chip alongside a 256mb chip, and if not, why?
2) I don't know the FSB speed on my computer but have read that there is program on the computer that will tell you. I have tried a coulpe different places but could not find it.
3) On the system info screen (windows xp) it tells me that i have 256mb physical memory but only 90mb physical memory available, what is using so much memory when i only have 1 application running?

Thanks!!!!!

 

[Codeine]

Ok, you have alot of questions, so i will try my best. First your memory usage problem..most people seem to forget that your running your operating system (Windows Xp or w/e). Plus you have small things in the back ground. Also i dont know what type of processor you have, but im guessing its slow.

Second question, i cant tell you if you can transport your RAM if i dont know what mobo. So i cannot predict that the mobo you will get will accept your RAM. But for your present computer (notebook) im pretty positive you dont have dual channel RAM, so you can most likly put a 512mb with a 256. I would call your company and ask if your mobo supports that much RAM first.

Final, for your computer spec's, go to google or yahoo type CPU-Z and DL it. This will tell you all your computer specs.

 

[æArchOAngelæ]

yeah u can use speeds higher but i dont know ur mobo and what is the max fsb supported but for ur purpose i would sugest sticking with a pc2100 and go wit 512 and if u go to google just type cpuz and download the program it will tell u specs for what u need also u can go to google and try typin pcmark04 and click on the website with the future mark and down from their that should help u also

 

[TheGoatRyder]

FSB is 100MHz, bus speed is 400MHz according to cpu-z. Motherboard will support up to 1GB Ram. Is there anything else that I can do to speed it up, any settings to change beyond the basic stuff?