A little something to keep in mind: is the software that you run, capable of using 2 processors? Just because there are 2 in the box, does not mean that you will get the power of 2. Most of the time the OS will divide up who is getting processor time and it is totally out of your hands. So in this case a single processor machine would most likely be best. Between IDE and SCSI, it use to be a question of how fast the drive spun at and how fast data was transfered back to the processor. The newer IDE drives at 7200 rpm are as fast as SCSI were a cuple of years ago. Keem in mind that SCSI (in a PC) require a special card that can add expense that you did not plan on. And lastly SCSI setup can be a tricky thing. Sometimes it matters what slot that the SCSI care is inserted into, is the device self terminating (this is a SCSI thing) and SCSI cables can be cost a pretty penny. regards, Philip