Performance Intel Pro 1000 MT (PWLA8490MT)
Petri Helenius
pete at he.iki.fi
Tue Apr 19 14:11:37 PDT 2005
Eivind Hestnes wrote:
> It's correct that the card is plugged into a 32-bit 33 Mhz PCI slot.
> If i'm not wrong, 33 Mhz PCI slots has a peak transfer rate of 133
> MByte/s. However, when pulling 180 mbit/s without the polling enabled
> the system is very little responsive due to the interrupt load. I'll
> try to increase the polling frequency too see if this increases the
> bandwidth with polling enabled.. Thanks for the advice btw..
>
There is something "interesting" going on in the em driver but I haven't
had the time to profile it properly and Intel has been less than
forthcoming with the specification which makes it more challenging to
try to optimize the driver further.
Pete
> - E.
>
> Jon Noack wrote:
>
>> On 4/19/2005 1:32 PM, Eivind Hestnes wrote:
>>
>>> I have an Intel Pro 1000 MT (PWLA8490MT) NIC (em(4) driver 1.7.35)
>>> installed
>>> in a Pentium III 500 Mhz with 512 MB RAM (100 Mhz) running FreeBSD
>>> 5.4-RC3.
>>> The machine is routing traffic between multiple VLANs. Recently I did a
>>> benchmark with/without device polling enabled. Without device
>>> polling I was
>>> able to transfer roughly 180 Mbit/s. The router however was
>>> suffering when
>>> doing this benchmark. Interrupt load was peaking 100% - overall the
>>> system
>>> itself was quite unusable (_very_ high system load). With device
>>> polling
>>> enabled the interrupt kept stable around 40-50% and max transfer
>>> rate was
>>> nearly 70 Mbit/s. Not very scientific tests, but it gave me a pin
>>> point.
>>
>>
>>
>> The card is plugged into a 32-bit PCI slot, correct? If so, 180
>> Mbit/s is decent. I have a gigabit LAN at home using Pro 1000 MTs
>> (in 32-bit PCI slots) and get NFS transfers maxing out around 23
>> MB/s, which is ~180 Mbit/s. Gigabit performance with 32-bit cards is
>> atrocious. It reminds me of the old 100 Mbit/s ISA cards...
>>
>>> <snip>
>>>
>>> HZ set to 1000 as recommended in README for the em(4) driver. Driver
>>> is of
>>> cource compiled into kernel.
>>
>>
>>
>> You'll need HZ set to more than 1000 for gigabit; bump it up to at
>> least 2000. That should increase polling throughput a lot. I'm not
>> sure about other polling parameters, however.
>>
>> Jon
>
>
>
> _______________________________________________
> freebsd-performance at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-performance
> To unsubscribe, send any mail to
> "freebsd-performance-unsubscribe at freebsd.org"
>
More information about the freebsd-performance
mailing list