Linux port.....

[andi payn]

On Fri, 2003-10-24 at 14:44, Alessio Caffi wrote:
> dear FreeBSD team:
> I am a new user to both Linux and FreeBSD. I installed
> both system (4.8 and slackware 9) under VMware for
> windows they are working ok.
> Before parting my HD and do a real installation ,
> without VMware emulator. I am interested to know which
> of one runs faster. What about Linux program under
> FreeBSD, will they run slower or same speed as native
> Linux OS.

The short answer is that most linux programs run at about the same speed
under linux and FreeBSD. Running linux software on FreeBSD is also about
the same speed as recompiling the source for FreeBSD native. This is
what you'd expect, and this is _usually_ what you get. There are a few
exceptions (all of which have nothing to do with the linux "emulation,"
but which will still affect you).

I should mention that I'm certainly not an expert--until the past few
weeks, I hadn't used a BSD operating system in years. Also, I'm using
FreeBSD 5.1 vs. various Mandrake versions, and (briefly) Redhat 6.2 and
8.1. But I can offer some observations from my (limited) experience.

1. Multimedia may be much slower on FreeBSD, if you have hardware for
which acceleration is either non-existent or harder to get working on
FreeBSD. On my ATI Rage, for example, I can't get DRI, or Xv, or vidix
working on FreeBSD. This means that full-screen games, OpenGL apps,
mplayer, etc. all run very slow on FreeBSD. If you don't have hardware
for which this is an true, or don't plan to do much multimedia/gaming,
this won't affect you; otherwise, it's a huge difference.

2. UFS seems to write significantly faster than ext3 in some cases.
Things like squid proxies, mail servers, web browsers, GNOME programs
that do too much gconf'ing, etc. seem noticeably faster in FreeBSD. This
only matters if you spend a lot of time running apps that don't play
well with ext3 (in which case you should be usin Reiser, XFS, or
whatever's best for your usage in linux anyway).

3. FreeBSD's swapping may also be smarter or faster. Or maybe not. I
know that, e.g., working with gigantic files in gimp seems to be a
little faster than under linux, and the memory-leak bug in SMAC doesn't
make the game slow to a crawl quite as quickly. This may be a
consequence of /tmp, etc. being on UFS, or something completely
different.

4. While running a similar set of services, FreeBSD may be using less
background processing time. Or maybe not. I definitely see significantly
lower CPU usage (idling under X, FreeBSD shows about 2-10% CPU, linux
about 15-35%). However, this may just be an artifact of linux's
notoriously bad reporting, or the fact that I'm using the O(1) kernel
and preemptible kernel patches, or maybe something stupid some GNOME
applet is doing because I configured it wrong under linux; who knows....
CPU-bound processes certainly don't seem to run a whole lot faster (as
they should, if this were something real).

Other than these cases, for the most part, I haven't seen much speed
difference with linux apps--or ports to FreeBSD.