SATA External Enclosure speeds

altivec_2.0altivec_2.0
Posted:
in Current Mac Hardware edited January 2014
The one thing I haven't seen is a SATA II External Enclosures. I've found many SATA ones, but will the "wiring" inside support SATA II speeds? I'd like to buy SATA II drives to prepare for the "future", and would also like to put them in external cases, but I'm worried the cases wont take full advantage of the drives capable speeds.

Comments

  • Reply 1 of 4
    mr. hmr. h Posts: 4,870member
    Quote:

    Originally posted by Altivec_2.0

    The one thing I haven't seen is a SATA II External Enclosures. I've found many SATA ones, but will the "wiring" inside support SATA II speeds? I'd like to buy SATA II drives to prepare for the "future", and would also like to put them in external cases, but I'm worried the cases wont take full advantage of the drives capable speeds.



    Isn't the SATA bus speed already well above the maximum bandwidth that a hard drive (as in the actual platter read/write speeds) is capable of? Surely there's only an advantage for SATA II if you have more than one drive on the same bus?
  • Reply 2 of 4
    ebbyebby Posts: 3,110member
    There are SATAII external cases, but they are really expensive. From what I can tell, they also use a special cable that is not compatible with normal SATA.



    Right now, Macs only use the original SATA and that is plenty fast for me. IMO, I would just ignore SATAII until more products come out and use the money you save towards SATAII when you need it. It is generally a bad idea to future-proof technology. (When you actually need it, it will be much cheaper than it is now.)
  • Reply 3 of 4
    altivec_2.0altivec_2.0 Posts: 995member
    SATAII Hd's are very cheap, The Hitachi 250 SATAII hd is only 3 dollars more than the SATA/150.I figured for 3 more dollars I'd jump into it. Also the Hitachi 500GB HD is want I'm interested in getting a SATAII external enclosure for.
  • Reply 4 of 4
    nguyenhm16nguyenhm16 Posts: 203member
    Quote:

    Originally posted by Mr. H

    Isn't the SATA bus speed already well above the maximum bandwidth that a hard drive (as in the actual platter read/write speeds) is capable of? Surely there's only an advantage for SATA II if you have more than one drive on the same bus?



    Yes, the fastest drives can deliver about 50MB+/s from the platters. Not sure about the exact number, but certainly less than even ATA-133 speeds. However, SATA-II would be a win in the case where you can get the data off of the drive's RAM cache. I don't think SATA was designed to have more than one device on a channel (at least I've never seen a cable that had more than one drive connector on it), unlike ATA or SCSI.



    Another thing most people don't consider is that their drive access patterns are generally continously streaming (sequential) disk access where such maximum speeds are critical. Most people's drive access patterns have short bursts and if you're multitasking maybe lots of random access in which case the number of I/Os [or transactions] per second is more important, and I've found that that number is pretty consistent for [S]ATA drives of the same spindle speed. Apple enabling or shipping drives with NCQ (tagged command queuing in SCSI) would help here.
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