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IDE v. SCSI
May. 7th, 2004 01:55 amI now get to wonder...
The old Toshiba Satellite 115CS's PCMCIA cards can't do CardBus, and Linux doesn't support DMA on PC Cards (16-bit version of Cardbus). This is due to the laptop not being PCI based. So, any IDE or SCSI PC Card I shove in there is stuck at PIO (Programmed IO) speeds.
With IDE, the main CPU has to take a bit of attention to work the controller and get things right. Cheap, but intensive.
With SCSI, the CPU just needs to say "HEY! THIS unit, THIS logical unit, THIS head, track, and sector, THAT many, and tell me when you're ready." A second CPU takes that, translates it to the drive, grabs it, flags the CPU, and hands the info over. Expensive, but relatively fast.
I'm wondering what's faster over that PC Card interface...
The old Toshiba Satellite 115CS's PCMCIA cards can't do CardBus, and Linux doesn't support DMA on PC Cards (16-bit version of Cardbus). This is due to the laptop not being PCI based. So, any IDE or SCSI PC Card I shove in there is stuck at PIO (Programmed IO) speeds.
With IDE, the main CPU has to take a bit of attention to work the controller and get things right. Cheap, but intensive.
With SCSI, the CPU just needs to say "HEY! THIS unit, THIS logical unit, THIS head, track, and sector, THAT many, and tell me when you're ready." A second CPU takes that, translates it to the drive, grabs it, flags the CPU, and hands the info over. Expensive, but relatively fast.
I'm wondering what's faster over that PC Card interface...
