[email protected] wrote:
16. Dec 2015 13:12 by [email protected]:
I don't have any figures to hand, but as an example: on an old laptop with 2GB of DDR2 RAM and a dual core Celeron processor, running a 64 bit system, at times, almost brought it to a halt, but a 32 bit system (I had it dual-booted) could still be slow but was much faster than the equivalent 64 bit system. Adding a further 2GB of RAM improved matters considerably. Of course, as there are so many other variables to take into account I'm not suggesting this to be a definitive study, although I think that it does indicate that a 64 bit system requires more horse power.
Interesting find. I wonder if this still holds with recent kernels and recent processors. So far I've only used 64 bit on systems with at least 3.5GB RAM and the results were always a (small) improvement over 32 bit.
I still use a 32-bit system every day. It is slower than my 64-bit systems, but quite stable. I last did a full update in June 2012, but it has better video than my newer systems and the speed for what I do is satisfactory.
One thing I noticed though is that when I build LFS with a 32-bit distro on a Core2Duo, it was noticeably faster than on my i686, even though the speed on the i686 (3.2 GHz) was nominally faster than the Core2Duo (3.1 GHz). That is because of other factors like cache, number of registers, new instructions, etc. As noted in the book, the difference between 32-bit and 64-bit speed on the same system is only about a 4%.
Adding RAM primarily helps if the system is going into swap. There may be some marginal speedups from caching if there is additional unused memory, but I doubt it would be noticeable without instrumentation.
On my i686 running all the programs I normally use, I am using about 2G of RAM with the rest free. In this case, the 3G that I have installed provides a reasonable buffer for other programs.
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