Eager zeroed disks are tremendously more overhead for backend storage.
Is your storage deduplicating?
No, PERC 730 doesn't support Dedup.
A thin provisioned vmdk reads from physical device and /dev/zero.
A thick provisioned vmdk on the other hand always reads from physical device.
Of course reading from /dev/zero is faster than reading from a real device.
and everyone around is stupid ?
for that reason in all low latency whitepapers made by vmware they suggest for better performance to have thick eager zeroed disks ?
it is not so easy :-)
Thin provisioned vmdks will perform good as long as they are almost empty. The more data there is inside, the higher the fragmentation-rate will be so the performance goes down again.
To get a good AND predictable performance the best choice IMHO is to use eager zeroed vmdks on an unfragmented datastore.
But IMHO the main reason to use eager zeroed thick vmdks is the much higher reliabilty of thick provisioned vmdks.