the complete list for best results:

maxRecvDataSegmentLen=262144
MaxBurstLength= 1048576
Maxxmitdatasegment=262144
FirstBurstLength=65536
DataDigest=None
maxoutstandingr2t=8
InitialR2T=No
ImmediateData=Yes
headerDigest=None
(deprecated)Wthreads=8

Be sure to set the same values at the initiator as well.