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Diferent use of Memory in 32 bits and 64 bits version

Asked by Jesus Gamio

Hi I have in my machine Xubuntu Feisty 32 bist and 64 bits but I found out that by default the 32 bist version uses just 64 MB of RAM and the 64 bist version use 142MB RAM.

Is the 64 Bits version uses more memory than th 32 bits ?

Is my system in 64 bits requirement more memory for the same aplications?

thank you for any help or reference

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Ralph Janke
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Massimo Forti (slackwarelife) said : 		#1

If I can I want to ask you if you have a 64bit processor and you have tryed to test the different performace of Xubuntu 32 and Xubuntu 64, Or you have 2 different machines, one with 32bit processor and one with 64bit.

Thanks

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Jesus Gamio (jgamio) said : 		#2

Yes I have 64bit processor. I used the same machine.

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Massimo Forti (slackwarelife) said : 		#3

This some benchmark:

http://64-bit-computers.com/linux-ubuntu-610-64-bit-vs-32-bit-benchmark-test.html

32 bit is more fast and use less memory.

thanks

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Best Ralph Janke (txwikinger) said : 		#4

Thanks for this question.

Yes, if you run software in 64-bit mode it will always use a lot more memory than in 32-bit mode. This is the nature of how a cpu works. A 64 bit processor has all opcodes align in 8 bytes, a 32-bit cpu in 4 bytes. Similarly, data in the memory is aligned on 8 bytes boundaries instead of 4 byte boundaries, since this allows faster access. This obviously leads to a lot of memory not being used (i.e. just filling out the opcodes or the space to the next boundary).

This is a issue of the processor demands and will be the same for any operating system you will use.

I hope this helps

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Jesus Gamio (jgamio) said : 		#5

Thanks Ralph Janke, that solved my question.

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Cesare Tirabassi (norsetto) said : 		#6

Another, perhaps small but still significant, factor is the pointer size. It is 4 bytes in 32 bits and 8 bytes in 64 bits.
If x% of your data is pointers this means an increase of x% of your memory footprint.

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Prabhat (prabhat234) said : 		#7

I have 32 bit system so can i install the ubuntu on my computer