hi,
this has been discussed very roughly before. but unfortunately no real
solution has been brought up so far (or i have not read it yet).
problem in short: the 82540EM intel gigabit adapter became very slow as
of 2.6.0-test4. maybe earlier versions were als affected aswell, but i
noticed this behaviour on test4 and later. the 'slowness' of the adapter
only affects a certain data direction. i performed the following tests
to show you what is wrong.
dummy data file was 34257856 bytes (34.3MB).
test machines were a pentium4 with the intel adapter, and a pentium2 266
with a lowcost realtek card (runs linux 2.4).
SCP:
e1000 -> 8139too 28.6KB/s
e1000 <- 8139too 4.6MB/s
SMB:
e1000 -> 8139too 3.0MB/s
e1000 <- 8139too 3.3MB/s
FTP
e1000 -> 8139too 54KB/s
e1000 <- 8139too 9.4MB/s
as you can see reveiving data is no problem at all (maybe another
protocol can create some problems in this case?). but sending data is
awesome slow! exception is the samba protocol. why is that? i thought
that samba may use udp instead of tcp. but iptraf did not show any udp
packets going around so i guess i was wrong.
the problem gets worse while trying to test things over the internet.
scp stalls incredibly often on my 256kbit/s upstream. so does ftp and
irc dcc protocol. irc dcc ends up with sending 0.3KB/s on a megabyte
sized file.
before people again trying to tell me that some duplex settings could be
messed up - then tell me why this should happen. when i boot into 2.4
kernel with that test machine the nic works without problems. so IF
duplex stuff is the reason for the hickups something must be wrong with
the duplex detection code in the new driver/kernel?
i tried vanilla 2.6.0-test5, 2.6.0-test5-mm2 and mm3 + 2.6.0-test5-bk4.
none of these gave any difference regarding network performance.