On Wed, Sep 17, 2008 at 1:51 PM, Bill Davidsen <davidsen@xxxxxxx> wrote: > Bingo wrote: >> >> Read this for a comparison in performance for 32 bit, and 64 bit linux: >> http://bingouv.blogspot.com/2008/08/desktop-linux-performance-comparison32.html >> . >> >> To summarize, you will notice the difference between 32 bit and 64 bit for >> CPU intensive tasks. But it won't change the world. This comparison is based >> on Fedora-9. >> > One thing that most people undervalue is that almost none of these tests are > actually done on 32 bit and 64 bit processors, they are widely done on the > same processor (to keep thing the same) and the 32 bit test is run on a 64 > bit CPU in 32 bit mode. > > This is important because the big difference between 8 and 16 bit, or 16 and > 32 bit was the longer registers and wider path to memory. And so the tests > were run on different CPUs. Running the test on the same CPU in two modes > gives far less improvement, and most recent tests measure only the > difference between modes. > > Since the three advantages of 64 bit operation are lower overhead with large > memory, ability to run larger user images, and a few more 64 bit registers, > it's not surprising that the benefits are not huge, and that many systems > will just not see any measurable difference, due to a lack of large > processes or memory. The overhead of PAE operation is generally hard to find > in the noise. > > Obviously there are loads which do show a larger difference, and some of > those loads are "real loads" rather than benchmarks and test cases, but for > most configurations and loads it can be "measured but not felt." > > Note: this is just to remind people of the factors involved, not to agree or > disagree with anyone. > > -- > Bill Davidsen <davidsen@xxxxxxx> > I believe the discussion is i386 (32-bit) vs. x64 (64-bit extended instruction mode for x86 processors). Dual booting the i386 and x64 versions of the OS on the same hardware should make a level playing field. -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
