Harddisk standard differences

I've added a new hard-disk to my laptop today. Now i wanted to compare the information available over the harddisk. So installed a tool called 'CristalDiskInfo'. A property from the information called 'Standard' is different at the new harddisk.

At the first harddisk it's: ATA8-ACS | ATA8-ACS version 4
And the 2nd: ACS-2 | ATA8-ACS version 6

  1. What does this 'standard' mean?
  2. Which one is better?
  3. Is there an performance difference?
  4. Is there a list/table where to compare them? I can't find anything.

Screenshots first harddisk:

First disk

Screenshot 2nd harddisk:

2nd disk


At the very basics, ATA means "AT Attachment" where AT references the IBM PC/AT with a 6 MHz 80286 processor introduced 1984.

Since then the ATA standard is updated continously to adopt high drive capacity and faster tranfer rates. Parallel-ATA uses 40 wire ribbon cable, while actual Serial-ATA (SATA) devices use thinner, 8 wire cables.

The actual ATA-Standard is the ATA8, you can find the difference between the ATA versions under http://en.wikipedia.org/wiki/Parallel_ATA#ATA_standards_versions.2C_transfer_rates.2C_and_features

ACS means AT Command Set, which describes how the computer commands the drive to save or retrieve data.