Poor network transfer speed

[Anonymouslemmin]

All,

I've just rebuilt my main machine onto older hardware, and I'm having really poor network transfer speeds since doing this.

The switch is a Netgear GS605G2 (10/100/1000). The network card in the Linux box is a Broadcom 4400 10/100BaseT onboard device (on an Abit KD7 motherboard).

All of the other machines on the network are Macs running at gigabit, full duplex (autonegotiated).

I've set the Linux box to 100/full duplex in /etc/sysconfig/network-scripts/ifcfg-eth0, but I'm only seeing speeds of around 600K/s when copying files. This is well below what I would expect.

I've tried replacing the cable, but the previous cable was working fine on the old network card anyway.

ethtool output is as follows:
Settings for eth0:
Supported ports: [ MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: No
Speed: 100Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: off
Supports Wake-on: g
Wake-on: d
Current message level: 0x000000ff (255)
Link detected: yes

ifconfig output is as follows:
eth0 Link encap:Ethernet HWaddr 00:50:8D:49:994
inet addr:xx.xx.xx.xx Bcast:xx.xx.xx.xx Mask:255.255.255.248
inet6 addr: fe80::250:8dff:fe49:99c4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7284 errors:0 dropped:0 overruns:0 frame:0
TX packets:5392 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5654882 (5.3 MiB) TX bytes:1320557 (1.2 MiB)
Interrupt:185

Any advice would be much appreciated!