Recommended Size & Durability of PCI Flash Storage

Discussion in 'Mac Pro' started by Average Pro, Dec 24, 2013.

  1. Average Pro macrumors regular

    Joined:
    Jul 16, 2013
    Location:
    Cali
    #1
    I need help from the techies. Please keep in mind I will be making assumptions below as I lack knowledge in this arena.

    As I prepare for the MP, I am trying to better understand what size PCI Flash Storage (SSD) to acquire. My computer currently has a 1TB HD and I come no where near that capacity ever.

    Based on my experience with Flash Cards (photo/video) the more they are used (loaded and erased), the faster they fail (obviously). Following this logic, it would appear that you wouldn't want to use your SSD the same way you utilized a standard hard drive (HD). For example, in addition to programs and OS, I place a lot of items on my Desktop and constantly use it as a temporary holding station until I delete or move the project to an external HD.

    Assumptions:

    1) Utilizing an SSD for anything more than software programs will lead to a faster failure.

    2) Utilizing an SSD for software programs and temporary holding spot for projects that are regularly edited, moved to external HD, and/or deleted has no impact on durability.

    3) An SSD will/not outlive a standard HD

    Got to get back to eating now.

    Thanks all.
     
  2. AidenShaw macrumors P6

    AidenShaw

    Joined:
    Feb 8, 2003
    Location:
    The Peninsula
    #2
    I think that all of your assumptions are basically incorrect.

    While flash does have a wear issue, for typical use as HD replacements in desktop systems flash is more reliable than spinning hard drives over the typical lifetimes of those systems.

    In particular, if the system supports TRIM and the SSD isn't run at 95%+ full all of the time you simply should not worry about SSD lifetimes.
     
  3. mrsavage1 macrumors regular

    Joined:
    Feb 1, 2010
    #3
    It depends if the ssd is an enterprise level type ssd.
     
  4. Average Pro thread starter macrumors regular

    Joined:
    Jul 16, 2013
    Location:
    Cali
    #4
    Concur

    Right after I clicked 'submit' I remembered, "SSD = no moving parts".

    Now I'm understanding why I've come across post where members are suggesting filling an external HD with a series of SSDs.

    And as mentioned in the response - it's all about the quality of the drive. This might be the way to migrate and upgrade. Keep my current FW and eSATA external HDs as uber-archival backups, while building SSDs to handle current projects.

    Thank you for the responses.
     
  5. cnstoll macrumors 6502

    Joined:
    Aug 29, 2010
    #5
    Get the ssd size you need to keep all of your apps and any working data set, such as photos, photoshop files, etc. you don't need to worry about having a few extra things like downloads or documents there. There is nothing wrong with doing that at all.

    One thing that has usually been the case with all spinning disks, and even some ssds, is that they tend to slow down as they get more full. Given recent tests I've seen of some of the tope nod ones that Apple will likely be using, that won't be the case here.

    I'd look at your current data set and multiply times 1.5 to figure out how large an ssd to get to account for future use.
     
  6. handheldgames macrumors 6502a

    handheldgames

    Joined:
    Apr 4, 2009
    #6
    IMHO...A 512GB OS X drive is ideal in my work flow. Internal for OS X / Apps / User Data.
    TB external for projects large data sets. A ramdisk for content creation and building code is essential for ludicrous speed.
     
  7. AidenShaw, Dec 25, 2013
    Last edited: Dec 25, 2013

    AidenShaw macrumors P6

    AidenShaw

    Joined:
    Feb 8, 2003
    Location:
    The Peninsula
    #7
    Please define "enterprise level SSD" with some examples and part numbers.

    One key factor might be the amount of "spare" space built into the drive.

    Typically a "consumer" drive might show up as a 256 GB drive (which really has 256 GiB or 274.9 GB of space). The roughly 7% difference is hidden "free" space that the drive uses for housekeeping and wear-leveling activities.

    A more conservatively spec'd drive might show up as 240 GB usable for the same 256 GiB raw capacity, or about 20% of the space reserved for housekeeping.

    If the system supports TRIM and you don't run the disk nearly full all of the time, there's no real difference between the two - unused space that's been TRIM'd is the same as hidden reserved space for housekeeping. You could also leave free space on the 256 GB drive by only creating a 240 GB partition for the same effect as the more conservatively spec'd drive.

    Or were you referring to phenomenally expensive SLC drives used for a caching tier in multi-petabyte enterprise arrays?
     
  8. mrsavage1 macrumors regular

    Joined:
    Feb 1, 2010
    #8
    http://www.kingston.com/en/ssd/enterprise/best_practices/enterprise_versus_client_ssd
     
  9. AidenShaw, Dec 25, 2013
    Last edited: Dec 26, 2013

    AidenShaw macrumors P6

    AidenShaw

    Joined:
    Feb 8, 2003
    Location:
    The Peninsula
    #9
    That's a nice vendor white paper, but few Mac Pros will ever need those features. Good quality standard SSDs have plenty of reliability for single system use.

    It would be interesting to find out the technologies in the Apple PCIe drives (and since they only have 7% overprovisioning, it doesn't sound like they're "enterprise" level);
     

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