On 6/25/12, Istvan Gabor
I have purchased a new computer with more RAM (8 GB) and newer processor (AMD phenom II x6). So far all my computers used 32 bit linux (opensuse). Windows users say that windows requires 64 bit system to recognize and use memory that is larger than 4 GB (>3.xx). 1. It is necessary to switch 64 bit opensuse to use 8 GB RAM? My 32 bit system sees 8 GB RAM (in kinfocenter); kernel 2.6.31.14-0.8-desktop #1 SMP PREEMPT 2011-04-16 i686 athlon i386 GNU/Linux.
Since the Pentium Pro, all Intel chips(other than the 400Mhz front side bus Pentium M chips) have had PAE(which stands for Physical Address Extension). PAE changes the memory address of a 32bit chip from 32bits to 36bits, which expands the maximum addressable physical limit from 4GB to 64GB RAM. However, since a 32bit chip can't use more than 4GB per process, PAE "swaps" memory from below & above the 4GB limit. So, if the data you need is located above 4GB, it has to be swapped down to be used, whcih can take more time(although it's extremely fast). Here's more info: http://en.wikipedia.org/wiki/Physical_Address_Extension.
2. If not necessary, what are the advantages of 64 bit?
64bit x86 doubles the amount of registers from 8 to 16, which helps out. Also, due to the design of the x86, a lot of things run much faster when ran in 64bit mode versus 32bit mode. Video editing & encoding is a prime example because more data can be manipulated at a time.
3. What are the caveats? I guess there might be programs that can run on 32 bit system only. Can I run these in a 64 bit OS? Is there some compatibility program?
All 64bit x86 chips have a full hardware 32bit x86 setup included. So, you can run 32bit apps full speed under a 64bit OS. however, due to the 64bit setup, running 32bit apps takes more resources under a 64bit OS than running a 32bit OS. The majority of Linux software is available in 64bit. Even Adobe Flash is 64bit available. However, things like Wine(to run windows programs) are 32bit for 32bit windows programs, etc. I have 2GB RAM in a 64bit Core2 chip, & I can attest to faster encode times. I have Wine installed, but use it rarely. I would recommend installing a 64bit OS on a seperate hard drive to make sure everything you need/use works ok before switching out completely. Good luck -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org