Latency too high with 6125XLG and 5900 ?

[fab2]

Hello,

I have a question about latency in my network, which include Blade servers for virtualization.

Topology:   HP C7000 Blade server 1 , embedding HP 6125XLG ---10G--- HP 5900AF-48G-4XG-2QSFP+---10G---HP 6125XLG embedded in HP C7000 Blade server 2

ping from one VM in Blade server 1 to one VM in Blade server 2 takes 0,3-0,6 ms.

Do you think those are regular values for such a network ?

I was expecting less, since data sheets for 6125XLG and HP 5900 resp. says "Latency 1us (store and forward mode", "10 Gbps Latency < 1.5 µs (64-byte packets)".   I know calculations are a bit complicated to go from latency to actual travel time, though.

Between 6125XLG and 5900 , 40G to 4x10G splitter cables are actually used.  All interfaces are in auto mode.

Do you think it is possible to decrease the RTT ?

I've heard about InfiniBand but unfortunately it is to late to go for that...

Thanks for your tips !