It's probably not worth a lot of time and effort. Narrow drives are SLOW, at that size you'll be lucky if they're 5400RPM, and a 2940UW will only sync at 20MB/s on the narrow channel. Software RAID would be the only way to set up a RAID-0 array and it will not boot. Processor loading wouldn't be greatly significant. I'd worry much more about power consumption and an array that runs just a little better than PIO mode. You could get a much better U2W RAID card on Ebay for low cost and a couple of significantly sized U2W 10K RPM drives for almost a song and have a much faster, more reliable, and less power hungry array, Or do the sensible thing and simply add another IDE drive and controller(if necessary).