How fast is the OHCI driver?

[Sebastian Huber]

On 03/16/2010 07:01 PM, Bernd Walter wrote:
> On Tue, Mar 16, 2010 at 04:46:19PM +0100, Sebastian Huber wrote:
[...]
>> Has someone values from other FreeBSD based systems with an OHCI controller?
> 
> I can easily get more with AT91RM9200 (also ARM9 with OHCI).
> A short test:
> [73]chipmunk.cicely.de# dd if=/dev/da0 bs=128k of=/dev/null count=100
> 100+0 records in
> 100+0 records out
> 13107200 bytes transferred in 16.762732 secs (781925 bytes/sec)
> 
> Speedwise the system is on the lowest end of ARM9 systems we support.
> 

Thank you for your reference values.  Actually my test setup on the FreeBSD
based system was bad.  I now have the following values:

TSZ:  Size of one transfer block in bytes
TIME: Time to transfer 1024 blocks in seconds
RATE: Bytes transfered per second

TSZ     TIME   RATE
    512   6.15   85250
   1024   7.17  146244
   2048   8.20  255750
   4096  10.24  409600
   8192  13.38  626951
  16384  21.50  780335
  32768  36.92  908841
  65536  67.92  988057
 131072 131.39 1021521
 262144 259.00 1036430
 524288 514.16 1044170
1048576 964.04 1048532

So it looks very good if you use the right transfer size.

Best regards,
	Sebastian Huber

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Sebastian Huber, embedded brains GmbH

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