33Mhz and 66MHz PCI slots and PCI-SCSI HBAs and StorEdge 3310s

On the 280R, PCI slot 1 is 66Mhz and the rest ( slots 2 to 4 ) are 33 Mhz.
On slot 1 and slot 3 are PCI-SCSI HBAs ( QLogic ISP10160 ) with a StorEdge 3310 attached to them.
Both arrays are in single-bus configuration.

I am mirroring between the two arrays using DiskSuite.
Now because only Slot 1 is 66Mhz, one can therefore notice that 3310 attached to Slot 1 is significantly faster:

*) LED Lights on drive blinks faster tham LED lights on drive on the other array
*) Cache Status is usually 24% dirty on array connected to Slot1, while cache status is always Clean on array connected to Slot3.


Now I was wondering if using a dual-bus configuration on the array connected to slot3 will make things faster,
and distributing the drives in the array so that half is one channel, and the other half is in the other channel.
Will it ?

 

Ugh! My fault. Reason why it was ... DiskSuite was doing the initial syncing between the submirrors.
Hence, one array is all doing reads, the other array is doing all writes.