Configuration of Compaq R3000

Jung-uk Kim jkim at
Thu Jan 27 10:59:37 PST 2005

On Thursday 27 January 2005 10:52 am, Kelly Black wrote:
> Hello,
> I have installed FreeBSD 5.3 on a Compaq Presario R3000. It has an
> AMD 64 bit processor.  First, I am very grateful for all of the
> work done by Jung-uk Kim. If it were not for his work it would not
> have been possible for me to get my machine going under FreeBSD.

:-)  You are very welcome.

> Second, there appears to be a very serious performance issue with
> this machine. I have a program that I use for benchmarks which
> approximates a nonlinear PDE. It uses a 300x300 matrix which is
> relatively small so it does not require much in the way of swap or
> memory caching. When I run this program under freebsd it takes 234
> seconds in user time (not real). I have CygWin installed on the
> windows slice and ran the exact same program. I have the 32 bit
> version of Windows XP. Under CygWin the program takes 155 seconds
> in user time.
> This is almost 33% better under MS windows and is a huge
> discrepancy! It seems clear that something isn't right on the
> machine. I have attached a copy of my kernel file. I have  applied
> many of the patches so generously made available by Jung-uk Kim on
> this list.  The times have remained consistent before and after all
> of updates.  I have used RELENG_5 as the src-all tag in my
> cvsup,conf,
> Any pointers on what I can do to tune this machine would be very
> helpful. Has anybody come across this problem?

Did you use 'acpi_ppc' driver?

You need this driver to run your laptop at full speed.  CPU speed will 
be automatically adjusted by CPU load.  However, it may take few 
seconds to get to the speed.  You can set the speed manually by:

sysctl hw.acpi.cpu.px_control=0

Please read comment in the acpi_ppc.c for more info.

Unfortunately if you run this laptop under heavy CPU load, CPU will 
heat up pretty fast and 'acpi_ec' will adjust delay to prevent 
excessive heat.  You can ignore this behavior by hacking acpi_ec.c, I 
believe but it's really bad idea.

Laptop is not for number crunching after all. ;-)

> By the way, I have used this same program to benchmark an opteron
> system. On that machine I installed FreeBSD 5.3 (generic kernel)
> and then installed gentoo (2.6.9 kernel). The times under both OS's
> were almost identical.

Hmm...  Interesting.  Can I see the source?


Jung-uk Kim

> Sincerely,
> Kel

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