2Gb vs 4Gb Disks - Which is faster????

We are trying to decide whether to go with 2gb or 4gb HP drives for our database using Informix. The HP salesman says that the 4gb drives are faster than the 2gb drives which is probably true. What I would prefer though is to go with many smaller 2gb drives so that I can spread my database tables out across as many separate physical disks as possible rather than having to put more tables on a larger disk. My logic says that 2 i/o's on two physical disks will normally be faster than 2 i/o's going to 1 physical disk especially if I'm on a multi-cpu box and am able to do the i/o in parallel. I would appreciate any comments or experiences regrading using HP 2gb vs 4gb in terms of performance. Thanks in advance. -- Melvin Mariney, Informix DBA e-mail: melvin.mariney2@bridge.bellsouth.com