Ultra ATA 66 hard drives are not necessary on a Mac. In fact, the Mac bus only supports 33 transfers. Though your drives would work, they'd only work at 33. Even in a pc you'd need a pci add on card (like the Promise Technology ultra 66 card) to enable 66 because most motherboards do not yet support 66; they're still moving at 33. Also, as all DV only transfers at 3+mbps, a Mac with a 7200rpm Ultra ATA/ Ultra DMA hard drive and a compatible NLE software (like EditDV) would be sufficient.(posted 9021 days ago)