I need to know the SATA specifications for the HDD and ODD on the Imac 20" mid 2009 and the Imac 27"Late 2009. If any of them is SATA III and which is SATA I and SATA II. Thank you

Hello i've been finding controversial answers for that. I upgraded my both Imacs to the SSD using the Optical Drive slot. I just want to know if they would run faster in place of the HDD, otherwise i'll just switch cables from the HDD to the ODD (which has the SSD now). Some say that from Late 2009 there are SATA III for the HDD and SATA II for the ODD and some other say it's from MID 2009 and some other even say it's SATA I for the ODD and some another one said it's SATA II for both on IMACs late 2009. Well need your help. Thank you!