[ofa-general] Drop in TCP performance when using OFED?

[Tziporet Koren]

Jan Ruffing wrote:
> Hallo,
>
> After I installed the OFED (1.4 beta), I noticed a drop in TCP
> performance via Infiniband: from 10 GBit/s to less than 8 GBit/s.
> Is that "expected behaviour"? Is there a way to avoid this performance loss?
>
> The HCA used in both test machines is a Mellanox Infinihost III Lx DDR
> HCA. Both machines run OpenSuse 11 with a 2.6.25.16 Kernel.
>   

Is it SDP or IPoIB?
What is the FW version you use?
>
> Performance with Open Suse 11 "out of the box", using Open Suse 11
> Infiniband packages:
>
> tamara iperf-2.0.4/src> ./iperf -c 192.168.2.2 -l 3M
> ------------------------------------------------------------
> Client connecting to 192.168.2.2, TCP port 5001
> TCP window size: 515 KByte (default)
> ------------------------------------------------------------
> [ 3] local 192.168.2.1 port 47730 connected with 192.168.2.2 port 5001
> [ ID] Interval Transfer Bandwidth
> [ 3] 0.0-10.0 sec 11.6 GBytes 10.0 Gbits/sec
>
>
> Performance after the Installation of ODED 1.4. beta:
>
> tamara iperf-2.0.4/src> ./iperf -c 192.168.2.2 -l 3M
> ------------------------------------------------------------
> Client connecting to 192.168.2.2, TCP port 5001
> TCP window size:   902 KByte (default)
> ------------------------------------------------------------
> [  3] local 192.168.2.1 port 38864 connected with 192.168.2.2 port 5001
> [ ID] Interval       Transfer     Bandwidth
> [  3]  0.0-10.0 sec  8.43 GBytes  7.24 Gbits/sec
>
>
> Thanks in advance,
> Jan
>
>