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<DIV><FONT face=Verdana size=2>Hi, all</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana size=2> When I use netperf to test SDP bandwidth
performance, I was confused with a problem. My test results show that the
bandwidth performance is better while the send and receive buffer size is
smaller. How does it explain? </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana size=2> How dose buffer size affect SDP bandwidth
performance?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana size=2> The table below is the result of my test.
The second column is the result with 16M send buffer and 8M receive buffer. The
third column is the result with 256K send buffer and 256K receive buffer. The
last column is the result with 16K send buffer and 87380B receive buffer.
</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana size=2>Package
Size(Byte)
Bandwidth(Mbps)<BR>128 684.51 682.55
725.43
<BR>256 1095.85 979.69 945.82
<BR>512
1498.62 1527.56 2474.6
<BR>1024 3191.12
4210.58 5147.91
<BR>2048 3994.1
5356.29 7212.09
<BR>4096 4546.15
6208.94 8127.58
<BR>8192 5962.7
7260.09 8621.43
<BR>16384 5100.91
6364.46 6575.32
<BR>32768 7446.83
6870.21 8889.46
<BR>65536 6617.12
7044.84 8992.61
<BR>131072 6587.27
6909.3 8867.24 </FONT></DIV>
<DIV> </DIV><FONT face=Verdana size=2>
<DIV><BR> My test is on two nodes. Each node is a DELL SC430 PC server,
which has one 2.8GHz Intel Pentium-4 processor and 1GB DDR II-400 main Memory.
These two nodes are interconnected with both Gigabit Ethernet and Mellanox
In?niBand DDR HCAs. </DIV>
<DIV> </DIV>
<DIV> Each node runs RedHat AS 4.0 with Linux kernel 2.6.20. I use
OpenFabrics OFED-1.2 and Firmware 1.2.0. Netperf has two options "-s" and "-S"
to set the size of socket send buffer and socket receive buffer. The former is
for local and the latter is for remote. I used these two options to set
different size values for socket send and receive buffer in the local and
remote. I think they represent the SDP send and receive buffer size,
right?</DIV>
<DIV> </DIV>
<DIV> Any reply would be appreciated! Thank you!<BR></FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV align=left><FONT face=Verdana color=#c0c0c0 size=2>2008-07-15
</FONT></DIV><FONT face=Verdana size=2>
<HR style="WIDTH: 122px; HEIGHT: 2px" align=left SIZE=2>
<DIV><FONT face=Verdana color=#c0c0c0 size=2><SPAN>linyao</SPAN>
</FONT></DIV></FONT></BODY></HTML>