Well. I plugged in my iMac (Intel, Core 2 Duo T7200, 2.00 GHz) to my gigabit switch and ran iperf on it in server and client mode. The only copy I could find for download (executable) was 1.70, and was compiled for the PowerPC Macs. Here are the results between the iMac and my server:
$ iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 192.168.27.10 port 5001 connected with 192.168.27.29 port 49371 [ ID] Interval Transfer Bandwidth [ 4] 0.0-20.0 sec 2.17 GBytes 930 Mbits/sec
$ iperf -t 20 -c 192.168.27.29 ------------------------------------------------------------ Client connecting to 192.168.27.29, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.27.10 port 44201 connected with 192.168.27.29 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-20.0 sec 2.18 GBytes 936 Mbits/sec
The server and the iMac seem pretty happy to talk to each other -- that's twice the performance of any other TCP result I've had! Just as a check, I plugged the PC into the same cable as the iMac had been plugged into:
$ iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 192.168.27.10 port 5001 connected with 192.168.27.23 port 4701 [ ID] Interval Transfer Bandwidth [ 4] 0.0-20.0 sec 386 MBytes 162 Mbits/sec
Much lower results. It seems to me that the problem is with the network hardware or TCP/IP stack on the PC side. Does anyone else want to venture an opinion? Or another test to run?
Kevin
On Wed, Apr 7, 2010 at 4:11 PM, Trevor Cordes trevor@tecnopolis.ca wrote:
On 2010-04-07 Adam Thompson wrote:
Actually, I was mainly hoping to verify that it was, indeed, a hardware problem. One person (Trevor) reporting similar results has fairly decent-quality GigE NICs on both sides – or at least what I *assumed* to be fairly decent-quality NICs!
I should hope so, my NICs are Intel server grade gigabit on the server and Intel high-end workstation grade gigabit on the client ($100-$300 NICs, retail).
Kevin, I didn't have time to scan your exact results, is it mostly pc->server that's slow or server<-pc? And your pc is Windows, I gather (XP?).
My big problem has always been windows->linux performance (but never linux->windows). I've given up on it for now, but one thing that made a HUGE difference was turning OFF jumbo packets. I instantly got 5X better performance with jumbo OFF. Yes, my switch is jumbo capable, and it was enabled, and set properly on the pc and linux. Go figure. I blame the Linksys WebSmart switch, but who knows.
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable