Mixed Manufacturer Drives in Array

[Ayman Altounji]

I have hard drives from different manufacturers with different geometries and firmware, and I would like to know what performance issues or problems there might be in mixing them in the same array with a Smart Array 5300 controller. I would also like to know who manufactured the following drives:
Compaq part no. 176496-B21 firmware BDC4
Compaq part no. 176493-003 firmware 3B06
If one of these is smaller and I use it to replace the larger one in an array, I feel there is a potential for loss of the integrity of the array. At the very least I believe I am losing the full potential of my array.