What is your network I/O?
Complementing the
http://computingplugs.com/index.php/SheevaPlug_Performance#Network_Performance figures I ran some netio sessions between my Sheevaplug (Ubuntu 9.04) and two XP Pro PCs.
Both PCs are directly connected to a cheap 8 port GigE switch as the connection to the Sheevaplug runs over a further GigE connection to another cheap 5 port Gig hub in the basement. So the connection between the PCs is one switch and between the Plug and the PCs two switches.
Here are some of my results:
2.6.35.4 -v Two Switches:
PC1/Sheeva 1k bytes: 74215 KByte/s Tx, 39725 KByte/s Rx.
PC1/Sheeva 2k bytes: 78028 KByte/s Tx, 46914 KByte/s Rx.
PC1/Sheeva 4k bytes: 87853 KByte/s Tx, 59131 KByte/s Rx.
PC1/Sheeva 8k bytes: 92203 KByte/s Tx, 73512 KByte/s Rx.
PC1/Sheeva 16k bytes: 97770 KByte/s Tx, 84692 KByte/s Rx.
PC1/Sheeva 32k bytes: 101956 KByte/s Tx, 89225 KByte/s Rx.
PC2/Sheeva 1k bytes: 72591 KByte/s Tx, 42768 KByte/s Rx.
PC2/Sheeva 2k bytes: 72562 KByte/s Tx, 49191 KByte/s Rx.
PC2/Sheeva 4k bytes: 89614 KByte/s Tx, 62997 KByte/s Rx.
PC2/Sheeva 8k bytes: 93679 KByte/s Tx, 81424 KByte/s Rx.
PC2/Sheeva 16k bytes: 98213 KByte/s Tx, 91791 KByte/s Rx.
PC2/Sheeva 32k bytes: 103042 KByte/s Tx, 94776 KByte/s Rx.
PC1/PC2 1k bytes: 111719 KByte/s Tx, 111726 KByte/s Rx.
PC1/PC2 2k bytes: 112113 KByte/s Tx, 111721 KByte/s Rx.
PC1/PC2 4k bytes: 114028 KByte/s Tx, 114229 KByte/s Rx.
PC1/PC2 8k bytes: 114121 KByte/s Tx, 114473 KByte/s Rx.
PC1/PC2 16k bytes: 114170 KByte/s Tx, 114373 KByte/s Rx.
PC1/PC2 32k bytes: 114572 KByte/s Tx, 114703 KByte/s Rx.
As you can see the throughput to the Plug is starting quite low at lower packet sizes - the receiving directing even lower, though it even does not reach the performance between the two PCs.
So I connected the Plug directly to the first switch as well and repeated the test.
2.6.35.4 -v One Switch:
root@Sheeva:~# netio -t PC1
Packet size 1k bytes: 40033 KByte/s Tx, 76293 KByte/s Rx.
Packet size 2k bytes: 48835 KByte/s Tx, 84415 KByte/s Rx.
Packet size 4k bytes: 61045 KByte/s Tx, 88771 KByte/s Rx.
Packet size 8k bytes: 75162 KByte/s Tx, 92650 KByte/s Rx.
Packet size 16k bytes: 85709 KByte/s Tx, 97744 KByte/s Rx.
Packet size 32k bytes: 88455 KByte/s Tx, 97974 KByte/s Rx.
However, elimination the one hop does not significantly improve the performance. (Note: you have to read the results as Sheeva/PC1)
Moving back to the original two hop network setup, but using another kernel showed similar results:
2.6.34.6 -v Two Switches:
root@Sheeva:~# netio -t PC1
Packet size 1k bytes: 40792 KByte/s Tx, 74743 KByte/s Rx.
Packet size 2k bytes: 48923 KByte/s Tx, 82903 KByte/s Rx.
Packet size 4k bytes: 61684 KByte/s Tx, 87789 KByte/s Rx.
Packet size 8k bytes: 75350 KByte/s Tx, 90809 KByte/s Rx.
Packet size 16k bytes: 85930 KByte/s Tx, 95666 KByte/s Rx.
Packet size 32k bytes: 89602 KByte/s Tx, 98683 KByte/s Rx.
