Difference between 6.2 and 7.0 Adaptec 39320D - 7.0 performing less

Gelsema, P (Patrick) - FreeBSD freebsd at superhero.nl
Tue Apr 17 15:52:05 UTC 2007

On Tue, April 17, 2007 17:18, Kris Kennaway wrote:
> On Tue, Apr 17, 2007 at 01:12:06PM +0200, Gelsema, P (Patrick) - FreeBSD
> wrote:
>> On Tue, April 17, 2007 01:03, Kris Kennaway wrote:


> >
>> > Apparently you weren't paying attention during boot, because 7.0 ships
>> > with heavy debugging options enabled, and tells you about it up front:
>> >
>> >      "WARNING: WITNESS option enabled, expect reduced performance.\n";
>> >
>> > Recompile your kernel with debugging options disabled before making
>> > performance comparisons.
>> >
>> > Kris
>> >
>> Ok, what you are saying makes sense. I did see the warnings and the bits
>> in the kernel config. The thing that triggered me was that when paying
>> attention during boot the SCSI Disk was detected as only 160.00MB/s
>> instead of the expected 320.00MB/s. The detection of devices is not
>> subject to debugging, is it?
> Someone else pointed this out to me, to be honest I didn't get that
> far in your email after noticing the big blunder of leaving debugging
> enabled :)

It's a lot of noise you get on lists, I completely understand your
response, would have probably responded in the same way. Next time I'll
write my emails a bit different ;-)

> I agree that the different speed negotiation is a likely potential
> cause of poor performance as well, but it really doesn't make sense to
> be making performance comparisons when one system has all possible
> debugging enabled and the other has no debugging enabled.

I am leaving the debug options on to get as much info for you guys to help
out. I am not comparing speed/performance at the moment. What I was doing
was to see if getting the patch diff from Ed Schouten in - to get the SATA
controller recognised - did change the performance. So I did a dd before
patch and after patch.

The patch allows the MCP61 to be recognised as such and use SATA300
instead of the UDMA33. (see mail sent yesterday to freebsd-current with
subject:Follow up: Support for nVidia MCP61 (S)ATA controllers).

Even with debugging on I would expect difference of performance.

Main reason for installing 7 is seeing if my hardware is supported, toying
a bit with new features, trying to get a better understanding of the



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