I spent several days with installations and various tests and found out that the i586-full-core gives me a download speed of 256 Mbps and the x86_64-full-core only 238 Mbps. I have an i686 Intel(R) Atom™ CPU D525 @ 1.80GHz Genuine Intel with 4GB RAM on bare metal. How can it be that there is such a difference in speed on exactly the same hardware in exactly the same configuration?
Thanks and best regards,
Bernd
I think the reason are security fixes in the kernel against the CPU bugs which are only available on 64bit. (e.g. the KAISER patchset) Even if the Atom CPU is not affected to the bugs the code is much more complicated now. Also 32bit code is a bit smaller so it fits better in the small caches of the Atom CPU.
Nevertheless, there aren’t Core Updates for i586 anymore.
@arne_f many thanks for the understandable explanation 
@bbitsch nevertheless, I would take the system with the higher speed 
@berndgz IPFire’s main goal isn’t speed, but security.
And support for i586 in Linux decreases, see blog articles on ipfire.org about end of i586 versions.
Minor support means slower integration of security patches, if at all.
Here is the link to the blog article blog.ipfire.org - New Year, More Bits
And i can say that we had many i586 specific bugs in the last year of i586 support. Also some compiler features for memory and stack protection are disabled in i586 version so we can only warn.
core162 is outdated, core167 has a newer kernel and many other fixes.
When i run the speed tests multiple times at different times of the day or week on my system i find more than 38Mbps variation without any hardware change. I am not sure how real, and how noticeable, your speed difference actually is.
Speed test is not not the end all test.
What is the difference in speed with addition services like ISP, proxy and VPN.
All apps that have continued ×64 optimization.
Kodi with x64 and 2 gig of ram is faster than 32 bit all day long.