by algorithm314 on 4/1/18, 5:41 PM with 22 comments
by krylon on 4/1/18, 7:54 PM
On x86/x86_64 the major advantage 64-bit mode brings to the table is support for more than 4 GiB of RAM. You get more registers and (IIRC) better support for position independent code, OTOH, pointers get bigger which may cause worse cache utilization. My personal experience after running both a 32-bit and a 64-bit system on the same machine was that performance was pretty much the same; either for me, performance was limited by other factors (cough I/O cough), or the advantages and disadvantages of 64-bit mode canceled each other out (or the difference was too low for me to notice).
On a device like the Raspberry Pi 3 (I happen to have one at hand), where the amount of RAM is a) fixed and b) less than 4 GiB, what advantages might a 64-bit OS offer?
EDIT: Thanks for all the answers!
by andreiw on 4/2/18, 12:30 AM
This is a 64-bit UEFI firmware for RPi3 that uses ATF for PSCI, and has USB, HDMI and SD card support. It has been successfully booting FreeBSD, SUSE Leap 42.3 and Ubuntu 18.04.
by brynet on 4/2/18, 2:24 AM
https://www.openbsd.org/arm64.html
by zokier on 4/2/18, 7:51 AM
Of course I understand why that is. I wouldn't be surprised at all if this port was result of less man-hours than it's peers, but the man-hours put into NetBSD are simply spread pretty thin.