Are you able to try the same activity without the Hardware Acceleration enabled and compare it to what you reported in this post?  The gains are relative of course, and I can't necessarily agree or disagree that what you are reporting is high; maybe other activity unrelated to your Storage vMotion is occurring simultaneously (I'm thinking you factored that in already though)?

I'd also like to suggest a quick 5 minute video from Chad Sakac if you haven't already seen it.  He provides a demonstration of this concept.  "Virtual Geek" compares the gains from both perspectives on the ESX server and the array via: esxtop, performance charts (from within VIC), and Unisphere Analyzer which you may or may not be licensed for.

http://www.youtube.com/watch?v=1sUS-LcEtBY

What isn't shown in the video and worth checking is what the datastore "Hardware Acceleration" status is.  With it enabled globally as you have done in the "Advanced Software Settings" by configuring: DataMover.HardwareAccelerated{Move|Init} to "1", check that the datastore's status shows as "Supported" now that you've performed (or attempted to) a hardware assisted eligible task:

1) Go to the "Configuration" tab of the ESX server

2) Under "Storage", review the column "Hardware Acceleration" status of the relevant datastore

3) The status will be one of three:
a) Supported
b) Not Supported
c) Unknown

As you'll see when you navigate to it as noted above, it is simply informational and not something you toggle.  However, it will let us know if the activity was successful (showing as "Supported") or unsuccessful ("Not Supported").  As mentioned in the ESX configuration guide (page 124):

http://www.vmware.com/pdf/vsphere4/r41/vsp_41_esx_server_config.pdf

[...]
Hardware Acceleration Support Status

For each storage device and datastore, the vSphere Client displays the hardware acceleration support status
in the Hardware Acceleration column of the Devices view and the Datastores view.

The status values are Unknown, Supported, and Not Supported. The initial value is Unknown. The status
changes to Supported after the host successfully performs the offload operation. If the offload operation fails,
the status changes to Not Supported.

When storage devices do not support or provide only partial support for the host operations, your host reverts
to its native methods to perform unsupported operations.
[...]

You didn't mention it, but can you also verify that the VMFS3.HardwareAcceleratedLocking is set to "1"?  It is enabled by default and may or may not change anything in your small test of migrating one VM but also worth checking.

Seems you've covered most of the bullet points, but check out the FAQ and compare:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1021976

[...]
Are there any caveats that I should be aware of?

There are a few reasons why a hardware-accelerated operation may fail.

For any primitive that the array does not implement, the array returns an error, which triggers the ESX data mover to attempt the operation using software data movement. In the case of ATS, it reverts to using SCSI Reservations.

The VMFS data mover does not leverage hardware offloads and instead uses software data movement if:

•The source and destination VMFS volumes have different block sizes
•The source file type is RDM and the destination file type is non-RDM (regular file) 
•The source VMDK type is eagerzeroedthick and the destination VMDK type is thin
•The source or destination VMDK is any sort of sparse or hosted format
•The logical address and/or transfer length in the requested operation are not aligned to the minimum alignment required by the storage device (all datastores created with the vSphere Client are aligned automatically)
•The VMFS has multiple LUNs/extents and they are all on different arrays

Hardware cloning between arrays (even if within the same VMFS volume) does not work.
[...]

From what you wrote, I'm thinking you've already seen the KB article though.

Hello Christoper,

yes i tryd the same task without enabled HW acceleration. I mornitored wit esxtop, performance chart (VI) and analyzer. there are the same IO ratio on whole monitoring tool. The storage system is supported. I know the video from Chad Sakac. I always written that the DataMover in the advanced settings mot modified and set to "1" and there is no issue by the list "The VMFS data mover does not leverage hardware offloads and instead uses software data movement if:"

Regards

Kai

You didn't mention anything about your Clariion configuration...

I think you have to set ALUA and another setting (can't remember off the top of my head) on the Clariion side.  Google  "Hardware Acceleration with vStorage APIs for Array Integration" and you'll find what you need.  This will include a long list of what works and what doesn't.  Sounds like you have read a lot of these articles already though.

If you are using RecoverPoint, there are some further restrictions to check out.

Dan

I had the same issue. After enabling ALUA using failover wizard storage vmotion started working as it should with the api