Date: Wed, 20 Apr 2005 00:12:00 +0300 From: Petri Helenius <pete@he.iki.fi> To: Eivind Hestnes <eivind@stabbursmoen.no> Cc: performance@freebsd.org Subject: Re: Performance Intel Pro 1000 MT (PWLA8490MT) Message-ID: <42657420.3040104@he.iki.fi> In-Reply-To: <4265724A.1040705@stabbursmoen.no> References: <20050419183335.F18008131@joshua.stabbursmoen.no> <42655887.7060203@alumni.rice.edu> <4265724A.1040705@stabbursmoen.no>
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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@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to > "freebsd-performance-unsubscribe@freebsd.org" >
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