Vista resize Read Chunks in SP1 from 4K to 32K ?

Just wanted to know if in SP1 updated the IO size access of Vista file
storage system.
As we know, in SP0, the access to Hiberfil.sys was done in Random
transactions of 4k (4096bytes) IO size.
Moreover, more than 50% of Windows Vista transactions were in 4Kbytes (see
graph).
Did MSFT changed this policy in SP1?
Rumors say that MSFT changed in SP1 the IO size to 32K or 64K.
If the rumors are correct; in what scenario application it is relevant to?
Hibernation, other?