PDA

View Full Version : [ubuntu] 32bit - 64bit memory question



ITdrummer
October 22nd, 2008, 10:55 PM
Hey guys,

I am currently dual booting XP(32-bit) and Ubuntu 8.04(64-bit), each on a separate hard drive.

My system has 2x1GB 800MHz ram. I realize that the maximum amount of memory for 32-bit OSs is around 3 gigs. If I were to double my system memory (2x1GB --> 2x2GB or 4x1GB) would this cause a problem for my Windows OS?

Im aware that the 64-bit ubuntu would be able to utilize all 4 gigs of RAM.

I guess the real question would be, Would windows just ignore the extra 1GB of RAM?, or is it not a good idea to run a 32-bit OS with more memory than it can utilize?

Pconfig
October 22nd, 2008, 11:01 PM
Windows would just ignore it. Shouldn't give any problems. Ubuntu 64 will be able to address all your memory or course.

AFarris01
October 22nd, 2008, 11:03 PM
Basically, yes, it would be ok to double your RAM, and windows wouldnt really care.

technically the max ammount of RAM a 32-bit OS can utilize is closer to 3.5 gigs. if you put 4 gigs of RAM in the PC, the windows will utilize something like 3.4GB, and ignore the rest... and ubuntu will use something like 3.8-3.9 GB.

hope that answers your question!

phidia
October 22nd, 2008, 11:08 PM
Actually 32 bit linux can "see" more than 4GB of ram if you install the server kernel.

I use 64 bit and support it but this question has come up before and it turns out that 32 bit can use all of the 4 GB (with the server kernel).

Do a search :)

Pconfig
October 22nd, 2008, 11:16 PM
Indeed, that's new to me. It seems to be significantly slower though.

http://en.wikipedia.org/wiki/Physical_Address_Extension

A nice recourse about PAE (the technique used). Getting a little offtopic though

ITdrummer
October 22nd, 2008, 11:51 PM
Thanks everyone. Thats all I needed to know.