[SunRescue] Problems with some quad ethernet action

[Bill Bradford]

On Mon, Dec 11, 2000 at 10:36:59AM -0800, Eric Ozrelic wrote:
> Is there a boot flag to switch to a 32 bit kernel mode? Will I have to
> re-install my
> entire system to regress to a 32 bit kernel? From what I've read isn't
> Solaris supposed to be binary compatible for applications that were written
> in
> both 32 and 64 bit mode? Does this mean the drivers that are compiled in 32
> bit mode won't work on a system configured with a 64 bit kernel?

Applications, YES.  Drivers, NO.  YOu have to have 32-bit drivers for a 32-bit
kernel, 64-bit drivers written for a 64-bit kernel.  End-user / userland
apps are different - you can run 32-bit apps on a 64-bit kernel, but not
64bit apps on a 32-bit kernel.  To boot exclusively into 32-bit mode, look
at the end of "man boot" where it talks about forcing Ultra 1 systems into
booting in 64-bit mode.  Should be self-explanatory.

> One more thing, I have the GCC compiler installed on my system and often use
> it to compile software that I get off the internet. My friend came over and 
> was helping me compile an application that was being finicky. After all was 
> said and done, he said for the cost I put into this Ultra system, and for 
> how much I had touted it as being cool, it compiled much slower then a lot 
> of lower end Pentium systems he uses with FreeBSD.

Just what systems is he comparing your box to?  In terms of straight
benchmarking for single-user "performance", I'd say an Ultra 1/170E is
equivalent to a PPro200 system with decent SCSI cards running FreeBSD 2.2 or
so (I've done these tests myself).  However, if you add any sort of decent
multi-user load to the machine, it will outperform the X86-based box.  When
we had the PPro200 and the U1 both setup at my previous employer, when someone
on the FreeBSD box opened up a 40mb mail folder in PINE, the box *locked* for
3-4 seconds while it read the file (this was with scsi, even).  Did the same
thing on the U1, and nobody noticed anything....  Of course, modern 500Mhz
or faster X86 boxes running FreeBSD/Linux/NetBSD/etc will appear to just
wipe the floor with an Ultra 1, due to plain speed.  However, the SPARC's
strongpoint is in its reliability and consistent performance under load.

> Is this because GCC is compiling 64 bit binaries for my system? Is there any
> reason that I should be running in 64 bit mode? Will things run faster and 
> compile faster in 32 bit mode?

You're already compiling stuff in 32-bit mode if you're using GCC - current
GCC/EGCS doesent have the ability to compile in 64-bit mode for Solaris.

> I'm very confused about all of this. I've read over the differences between
> 32bit and 64 bit mode from Sun for Solaris 7. Now I think I don't really 
> need to be using 64 bit mode.

I've never really seen an advantage to 64-bit mode, but then I'm not doing
anything yet that needs the expanded capabilities, other than the slightly
better performance running the 64-bit kernel.

Bill

-- 
Bill Bradford       |    "Do you expect me to talk?"
mrbill at mrbill.net   |    "No, Mr. Bond, I expect you to die!"
Austin, TX          |        -- "Goldfinger", 1964