[Filmo]

I'm having a wierd problem I can't figure out on a brand new 17" iMac Core 2 Duo.

We've got a gigabit network. I've got a server running OS X Server 10.4 with gigabit

When I mount a volume on the new iMac and down load a large media file, it creeps along at 3 to 6 MB/second

I can mount the same volume on our G5 and other gigabit equiped Macs, and they can pull from the server at close to 35 MB/second. (pretty much the speed of the drives on the server.)

I can 'write' to the server from the iMac at about 25 mb/second.

What gives with the ridiculously slow read rates on this new iMac? Where should I look to track down this problem.

Things I've tried:

1) switched cables and port on the switch. No Difference.
2) turned apple share on/off in the Networking panel, No Difference
3) manually set the Ethernet device to gigabit, No Difference.

????

17" iMac, 2.0GHZ Core 2 Duo, 1.5 GB/Ram - Paralells installed (but not running)

[Nivag]

not sure what to suggest, but i read somewhere that the Configure IPv6 option, at the bottom of the Ethernet TCP/IP settings, can cause problems (can't find a decent link though)

on my MacBook i've got it switched off and it connects fine on a Gigabit network.

[Big Mac]

What does IPv6 have to do with the OP's problem?

[Nivag]

I found out/remembered why I switched off IPv6, it was causing slowness when connecting to the internet.

Sluggish FTP and SSH - The macosxhints Forums

this is an old link
OSX-XPPro Network Problem - 2CPU.com Discussion Forums

[Filmo]

I'm not sure what fixed it, but the problem seems to be related to the 'imported' user profile from OS X 10.3.9.

When I set up the new iMac, I used the utility to 'import' the user from my old machine. For whatever reason, I could never get the network control panel to work correctly.

I created a new user and manually moved everything over. It still didn't work right, but at least the network control panel wouldn't crash everytime I opened it...

Finally, I created a new 'Location' the Network control panel. This fixed it.

So to recap, when I leave it on "automatic", download speeds are compromised. When I created a new 'location' with all the same settings as 'automatic' it now works correctly. Go figure.