VMware SAN restore very slow

Hi,

i have a problem by restoring VM's over SAN. I want to restore different VM's (thick - eager zeroed vmdk's) over SAN. The troughput is less then 25 MB/s (20 MB/s in a middle). With an NBD restore i get a througput about 45 MB/s but i won't restore over LAN. The backup over san is okay (70 MB/s). What could be the problem?