Re: [SOLVED]Re: Only 8 MB/sec write throughput with NetBSD 5.1 AMD64

changing MTU won't help really. it would also cause lots of other problems (=
like fragmentation over your Internet connection) and every device on your d=
eity would need to be set for the same MTU. Plus you should be able to push w=
ay more bandwidth without it. higher MTUs used to be a way to increase perfo=
rmance for things like iSCSI but that's not really the case anymore, even wi=
th 10 Gigabit Ethernet. So even 10 gigabit environments choose not to do jum=
bo frames.=20

If your network card is PCI, your bandwidth will be limited to about 200-250=
 megabits per second (which is about 25-35 MBytes/s) because of the bus spee=
d. PCIe will handle full duplex 1 gigabit no problem.

Tony




Sent from my iPhone

On Oct 9, 2011, at 9:05 AM, Manuel Bouyer <[email protected]> wrote:

> On Sun, Oct 09, 2011 at 08:38:50PM +0530, Ravishankar S wrote:
>> Thanks to all who replied. dd now shows 67 MB/sec!!. However, i have
>> another question. I can now ftp @ 25 MB/sec and it never increases
>> beyond this point. I have a dlink gigabit router and gigabit cards on
>> both ends. client is an  ubuntu laptop
>=20
> What does ifconfig -a shows ? You can also test network speed with
> a tool like ttcp, is't more usefull to explore network performances
> than ftp (which mixes performances of different subsystems).
>=20
> Note that not all gigabit network adapters or switches can support a
> sustainted link-rate traffic, but 25MB/s looks low anyway
>=20
>> Any other areas to explore to increase throughput? I see MTU set at
>> both ends at 1500 - any benefits to increasing it to 3000 - this will
>> enable jumbo frames automatically??
>=20
> It should.
>=20
> --=20
> Manuel Bouyer <[email protected]>
>     NetBSD: 26 ans d'experience feront toujours la difference
> --