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Yes, unfortunately it's one of those "where is the bottleneck" type questions.

C:\Users\sg\Downloads>iperf -c -t 30

Client connecting to, TCP port 5001
TCP window size: 8.00 KByte (default)

[156] local port 50710 connected with port 5001
[ ID] Interval Transfer Bandwidth
[156] 0.0-30.0 sec 1.02 GBytes 293 Mbits/sec

I'm not expecting anywhere near 1000 Mbit, but certainly not ~300 either.

My house is wired with Cat 6 cable. It's all terminating at a patch panel, and connected to a switch (D-link DGS-1016D).

I've got a HP Proliant N40L Microserver running Windows Home Server 2011 doing server duties including media streaming (the *.10 I benchmarked against). The HDDs are the Western Digital Caviar Green (2x EARX in a non-raid configuration)

I'm using a laptop (*.15), and there's about 3 other machines hardwired (including a PC, printer, and media player)

I also have a Netgear WNDR3800 router.

I've updated the drivers of the WHS2011 and my laptop.

Does anyone have any suggestions on where the problem might be or how to troubleshoot? I'm currently investigating Wireshark to see if I can narrow down the problem.


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Are you sure all devices are connected on their respect 1000 port instead of 10/100 port? – Ramhound Mar 6 '12 at 12:44
That's about what I'd expect in practice:… You might get slightly higher numbers if you increase the TCP window, or do your test with a pingflood or one-directional UDP blast. – pjc50 Mar 6 '12 at 13:38

You have not-so-bad-results

>netio -M -t

NETIO - Network Throughput Benchmark, Version 1.31
(C) 1997-2010 Kai Uwe Rommel

TCP connection established.
Packet size  1k bytes:  16.01 MByte/s Tx,  9.19 MByte/s Rx.
Packet size  2k bytes:  14.89 MByte/s Tx,  8.44 MByte/s Rx.
Packet size  4k bytes:  14.90 MByte/s Tx,  11.78 MByte/s Rx.
Packet size  8k bytes:  16.07 MByte/s Tx,  13.68 MByte/s Rx.
Packet size 16k bytes:  16.48 MByte/s Tx,  15.34 MByte/s Rx.
Packet size 32k bytes:  16.20 MByte/s Tx,  15.95 MByte/s Rx.

It's my "gigabit", Atheros-DLink pair (MiltiCo in the middle, heterogeneous links in it)

With Atheros-Atheros pair I can get ~30 on max packets size. Jumbo-frame add ~10-15%. End hosts is mostly reasons of speed degradation (bus width, NICs)

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