HP P4000 VSA Performance / Jumbo Frames

[ITThies]

Hello,
I´ve some performance issues on my HP VSA System.
I´m having a regular speed of about 50MB/s and about 3.000 IPOS. A virtual machine thats directly located on the local server storage will get up to 500MB/s and more that 40000 IPOS!
To get more speed out of the vsa, I want to enable Jumbo Frames, but thats not possibe. When I set the Jumbo Frames option to 9.000 as recommended, it will be reset to default automaticaly. Its the same for the flow control option. I already changed the jumpo frames options ob the dvSwitch Group and on the physical network switch.

The dvSwitch Group for the storage interface is equiped with two gigabit ethernet interfaces.

Any advice or further informations required?