(Very) Poor Performance FAS 2240 Flash Pool


we got a new FAS 2240 with a 11.5TB Flashpool (SSD + SATA), 10Gbit Network and Vsphere 5.5. Compared to our old FAS 2040 with 4GB FC the performance with Flashpool is not as good. For example running two storage vMotion operations at the same time, all VMs on the Flash Aggregate show warnings for disk latency problems. Logging in remotelty to a Windows VM you can really feel how slow it got. Looking at the bandwidth usage on the 10Gbit Switches (IBM) we can only see 1Gbit usage during storage vMotion. Currently we have not set the MTU to 9000. I'm not sure if it is a network problem, but given that we only have 1Gbit traffic on a 10Gbit network connection it is very unlikely to be the root cause. Has anyone similiar experience?

Best Regards,