IDS 10 disk configuration

We are migrating one of our HP-UX 11i database servers to a new disk array and upgrading it from IDS 9.3 to IDS 10 at the same time. Current disk array is an attached SCSI RAID 5 array, forgive me Art. The new array is a HP XP128, RAID 5 as well but it was installed before I had much say in things and before I drank of the RAID 10 cool-aid, so once again forgive me Art. The old disk layout consists of a bunch of 2GB devices but we have several tables that could benefit from larger devices. I plan on leaving my dbspaces just as they are now but utilizing one large chunk instead of several 2GB chunks. Does anyone in this group have a rule of thumb or recommendations for the device configurations? Would one large device divided among all of the dbspaces be just as good as 20 smaller devices? I would think not but cannot justify that thought with any facts. I'm leaning toward n devices of x size so that all of the devices are the same size and I'll split up the data how I want. The x size would be some factor of what's best for the array. This is a unique opportunity to implement an IDS 10 install with the best configuration possible so I thought that I'd query the community as see what was said. DL sending to informix-list