The best replacement for sata 2 is sata.

The best alternatives to sata 2 are rated as following:
★★★★★  sata
★★★★★  sata 3
★★★★★  ide
★★★★  sata 1
★★★  3 ssd
★★  scsi
★★  sata 3 cable
★  3 cable
★  sata 3 ssd
★  sata3
★  usb 3
★  firewire 800
  sata 150
  usb 3.0 speed

Your alternative for sata 2 is not listed? Suggest!
Speaking about sata 2, one probably shouldn't forget about ssd.

Other search terms related to sata 2 and their ratings are:
★★★★★ ssd
★★★★★ sata 3
★★★★ sata 3 ssd
★★★ sata 3 drive
You have in mind a companion for sata 2 and it is not yet here? Propose!



Google Trends

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sata 2
sata
sata 3