PowerPath LoadBalancing

Hi,

we have a cx4-120 box, SPA conected to FCSwitch1 & FCSwitch2 and SPB connected to FCSwitch1 & FCSwitch2, the host is connected to the FCSwitch1 & FCSwitch2 with 2 HBA's, so we have 4 paths:
hdisk2 Available 05-08-02 EMC CLARiiON FCP RAID 5 Disk
hdisk3 Available 05-08-02 EMC CLARiiON FCP RAID 5 Disk
hdisk4 Available 0C-08-02 EMC CLARiiON FCP RAID 5 Disk
hdisk5 Available 0C-08-02 EMC CLARiiON FCP RAID 5 Disk
hdiskpower0 Available 0C-08-02 PowerPath Device

When there is write activities on hdiskpower0 volume we figure out that only 2 paths are used:

0 fscsi0 hdisk2 SP A3 active alive 16 0
0 fscsi0 hdisk3 SP B3 active alive 0 0
1 fscsi1 hdisk4 SP A2 active alive 25 0
1 fscsi1 hdisk5 SP B2 active alive 0 0

My question is:
Is this normal because Clariion has an Active-Pasive configuration ?
For a Symetrix box, powerpath will use all 4 paths ?

Thank you for any suggestion !
Dan