On Sun, Dec 13, 2009 at 8:16 PM, Paul Jakma <paul@xxxxxxxxxx> wrote: > On Sun, 13 Dec 2009, drago01 wrote: > >> such a setup does not make much sense, when your hardware supports x86_64 >> not using it for userspace is a waste .... > > a) i386 has a lower memory footprint, as has been mentioned in this > thread. Yes which is pretty much the only valid complaint but trading memory for performance is a price I am willing to take ... > b) The amount of code on your system that is CPU bound and/or > memory-bound due to register pressure, to an extent that the x64 > registers would make an appreciable difference is probably not > that significant > > - kernel hotpots The kernel doesn't do any have computing... > - graphics hotspots (X server perhaps) > > I havn't measured this, but nor have the people who say x86_64 is > faster AFAICT, and there's plenty of experience to say that most > software is far from CPU bound or memory bound. Yes but the stuff adds up, you gain almost nothing by running i686 code but where it matters x86_64 can make a HUGE difference. > c) There is a definite cost to a distro in having to maintain 2 > x86_64 and i386 as separate arches Not a reason to move forward with hardware development. > > d) Like or not, i386 is the de-facto standard for binary interfaces: > > - Netscape plugins This is slowly being fixed. > - Windows executables Nobody stops you from running i386 apps on a x86_64 system. > - VM images to run in, say, QEMU/KVM > - Sandboxing technologies for, say, browser plugins (I think > Google have stuff in this area) > - Free software windows-only apps (don't know if they exist) > > All the code here can be open-source/free-software and still be > relying on i386 as a widely known and hence convenient > /interface/. As such, it likely needs to be supported on x86_64 > kernel-based systems anyway, as performantly as possible. (And > yeah, I gather KVM x86_64 doesn't work for i386 VMs - annoying). Er.. don't quite get your point here, what is stopping me from running i686 VMs on a x86_64 host? I have been doing this for a while and there are there problems (you don't even need multilib for that) > So personally I think x86_64-pure is unrealistic and, independently, I think > 32-on-64 makes sense, but hey. :) I did not suggest using pure x86_64 but using x86_64 where we can (ie. not just the kernel). -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
