MBP: Upgrading Hard Drive: SATA 1.5 or 3.0?

Discussion in 'MacBook Pro' started by legaleye3000, May 8, 2009.

  1. legaleye3000 macrumors 65816

    Jul 31, 2007
    I see 2 different SATA speeds. 1.5 and 3.0 gb/s. Does my early 08 MBP support both? Thanks.
  2. MikhailT macrumors 601

    Nov 12, 2007

    Only the unibodies have the 3.0Gbps.
  3. ab2650 macrumors 6502a

    Jun 21, 2007
    However, I think all SATAII drives are backwards compatible with SATAI. That's to say, it shouldn't affect what drive you purchase.

    A SATAII drive will run at 1.5Gbps in a '08 MBP.
  4. MikhailT macrumors 601

    Nov 12, 2007
    SATA 3.0Gbps is fully compatible with SATA 1.5Gbps interfaces, no problem there. However that is not to say that it doesn't have "any" effects. It does depending on what drive he get. Good quality SSDs can exceed SATAI speed and can be at the end of the SATAII speed, so getting those drives will limit the transfer speed to SATA I speed, which means it does have an effect on those drives.
  5. ab2650 macrumors 6502a

    Jun 21, 2007
    Theoretically speaking, isn't even a good SSD maxed out at around 250MB/s (~2Gb/s)? I don't think the (theoretical) loss is much and only on the bleeding edge.

    This also doesn't take into account burst speed vs. sustained transfer rate. I don't think the OP is going to be losing all too much worrying about the SATA 1.5/3.0 Gb/s debacle. Obviously 3.0 is better, but he'd be hard pressed to see much difference in real world usage IMHO.
  6. MikhailT macrumors 601

    Nov 12, 2007
    (1.5Gbps= after overhead is 150MBps, 3Gbps= after overhead 300MBps)

    Good SSD (at this moment in time) can do sustained 250MBps/200MBps no problem and this isn't a theory, its a fact. Vertex and probably Samsung can do that easily. With 1.5Gbps interface, the SSD is limited at 110MBps/110MBps. In terms of snappiness, it's the same .01ms at both interface speed. So yea, a casual user won't notice the difference but a heavy transfer based user will notice the gains.

    Internal flash NAND is limited at around 20-40MBps (ONFI 1.0), SSD controllers often combine data channels into one which is how it push 20MBps to 250Mbps easily in both read/write.

    in very near future Flash NAND chips will be at ONFI 2.1 spec which can do 166/200MBps. Combine just two chip into one channel, we already talking 400MBps easily which is beyond SATA II interface speed. They already working on ONFI 3.0 right which is speced at 400MBps per NAND.
  7. alphaod macrumors Core


    Feb 9, 2008
    Actually all MacBook/Pro notebooks releases after August 2007 have SATA 300
  8. MikhailT macrumors 601

    Nov 12, 2007
    Well that's not true at all.
    My early 2008 MBP is still at SATA 1.5Gbps. (I got mine in April 2008)

    The mobo chipset may support SATA 3.0Gbps but Apple clocked it at 1.5Gbps for any laptop before unibodies.

    I may be wrong but as far as I am aware, only the unibodies got the unlocked SATA 3.0Gbps.

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