That's likely the issue, reading/writing from same disks and host.   Have you tried copying from the array to the local datastore or vice versa?   Is this for a test, curious why you are moving it to the VMFS datastore.  You also must be using the ESX GUI to do the upload?  I've noticed copies via the ESX GUI are never very fast.   On the ESX server what are you using for a Pathing policy?   FIXED, Round Robin or have you installed the MEM MPIO module? 
Hi all, Was hoping someone may be able to advise on a potential issue we're seeing with our SAN.  Now I should mention that we're very new to Equallogic and this our fist SAN so we're learning at present. We are running Windows Server 2012 and have one drive connected to the PS4100X via MS iSCSI initiator and another via a VMFS volume on VSphere 5. We recently copied a large file 213 GB from the drive connected via MS iSCSi to the VMFS volume. The speed we were seeing on server copy was 85mbps which seems a little slow. I had a look at SAN HQ and noticed the following: Sorry, looks like my screen shots didn't make it into the post! The latency we were seeing was:Reads - 11.9msWrites - 152.6msWeighted Avg - 102msAverage I/O rate: 53.1MB/secAverage IOPS: 325.8Average Latency: 102.1msAverage I/O sice: 167.0KBRead/Write %: 35.9% / 64.1%Estimate I/O Load: High Should we be seeing this much latency and should we be seeing a faster copy speed ? Our Equallogic and Powerconnect switches were set up by DELL and this is the first large file copy we have done. Appreciate any thoughts you may have on this. We're running firmware 6.0.1 Thanks!
Slow Copying Files on Equallogic PS4100X - High Latency