What's the big deal with SSD's?

Discussion in 'Mac Basics and Help' started by hyroboarder, Aug 6, 2009.

  1. hyroboarder macrumors member

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    Sep 1, 2006
    #1
    I've been researching the forums lately and many people are recommending solid state drives for potential mac buyers. What's the scoop on them? I'm ordering a 17" mbp in the coming weeks and would like a storage medium that will match my processor and ram. Also, are the ssd options on apple's side worthy equipment? Would a similar ssd be much cheaper off newegg or amazon?
     
  2. thegoldenmackid macrumors 604

    thegoldenmackid

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    #2
    I mean, most users don't need an SSD. For the typical user it is a large waste of money.
     
  3. nuckinfutz macrumors 603

    nuckinfutz

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    #3
    Intel SSD are the fastest for general computing (i.e fast random reads and writes)

    Apple doesn't OEM them so you'd be looking at a Samsung SSD if you purchased it through Apple.

    :apple:
     
  4. rgarjr macrumors 603

    rgarjr

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    #4
    What kind of work would you have to be doing on the Mac to be able to benefit from these new SSD's?
     
  5. gusious macrumors 65816

    gusious

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    #5
    After someone answer this question,can you please tell me what are the pros and the cons of these dirves?
     
  6. BlueRevolution macrumors 603

    BlueRevolution

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    #6
    Pros:
    • SSDs are much faster than platter drives at random read/write, and somewhat faster at sustained transfer.
    • They're much more resistant to shock damage because they have no moving parts.

    Cons:
    • They're expensive.
    • Modern filesystems are still designed with the strengths and limitations of platter drives in mind.

    SSDs are definitely the way of the future, but that future hasn't quite arrived yet.
     
  7. gusious macrumors 65816

    gusious

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    #7
    Thanks for your reply.

    I've heard that if you erase them completely they may stop working or something. Is this true?
     
  8. nanofrog macrumors G4

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    #8
    A single SSD has the ability to get as high as 250MB/s sustained transfer rates for a single drive, and they're faster at random access than any other drive technology. This is great for performance, and has a place in the laptop market. Mechanical drives (single disk operation) can't touch this. Not even SAS models.

    There is a downside of course, and thats cost/GB. Most of them are small, as 256GB being the large models ATM (keeping it at 2.5" models). Performance will vary, depending on the specific model/manufacturer.

    As for purchase location, you'd likely be better off going with a 3rd party vendor, such as newegg, and pick the drive that best suits your needs. Not all SSD's are the same, as they can differ considerably in both performance and cost.
     
  9. Makosuke macrumors 603

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    #9
    No.

    There are some quirks about the way in which SSDs work, some of which as BlueRevolution said are due to current data-management techniques which are heavily based off rotating drives. There are also, theoretically, longevity issues for extremely large numbers of read-write cycles. Emphasis on theoretically because in practical use the drive will almost certainly break long before the read-write limits are hit.

    But regardless, unless there is a specific bug in a particular drive's implementation, erasing one certainly isn't going to kill it.
     
  10. orpheus1120 macrumors 65816

    orpheus1120

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    #10
    SSDs are for those with little patience.

    If you are like me, who wants to bootup your mac in insanely fast time, open and shut apps without waiting, and sleeping your mbp without waiting for the hdd to park before you carry it around, then SSD is for you. Of course on top of these is if the price of SSDs doesn't scare the sh*t outta your pants.
     
  11. John Jacob macrumors 6502a

    John Jacob

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    Columbia, MD
    #11
    Question on random vs sustained

    This is a general question I have had for a while on SSDs. Why are random transfers (reads or writes) slower than sustained transfers of the same kind?

    I can understand why a random read would be slower than a sustained read (or a random write slower than a sustained write) on a conventional hard disk. This is because the disk has to spin and the head has to move to the correct location of the disk. But on an SSD with no moving parts, in theory shouldn't it take the same time to access any location (address) on the drive? Why then, are random reads and writes slower than sustained reads and writes on SSDs? :confused:

    Edit: Thanks, nanofrog, that makes a lot of sense!
     
  12. nanofrog macrumors G4

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    #12
    The data in the blocks is much smaller (i.e. 4k block size, but maybe as little as a single bit resides there). Yet the time to read/write is the same, as it reads the entire block, whether full or not. So it affects the averages (less data divided by the same time needed to perform the same task on a full block).

    Hope this makes sense, as I was trying to keep it simple. :)
     
  13. nuckinfutz macrumors 603

    nuckinfutz

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    #13
    The storage subsystem is the slowest subsystem in your computer. It's orders of magnitude slower than CPU cache, system RAM etc. Any significant improvement here will benefit your system greatly.

    Many people seem to reference application launching as a primary benefit for SSD but that's really only because that speed increase is a bit easier to see.

    What's harder to "see" but easy to see is how SSD allows Spotlight to return faster search results or how multi tasking improves because the latency of SSD is many times faster than rotating discs.

    Anandtech said the best way to understand the effects of SSD is to get used to computing with one in your system and then pull it out. It is then you'll understand the impact they have on your system.

    No one can tell you what's valuable or a waste of money. That's a personal decision. If I'm buying a new computer I want it as fast as I can afford. I want a lot of RAM and fast storage.
     
  14. uberamd macrumors 68030

    uberamd

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    #14
    The future will never arrive, as it will always be the future. :)

    The one thing that scares me about SSD is the write cycles. Plain and simple. With hard drives I understand that they die due to moving parts, and you can hear the clicks of death and all that jazz before they die, but with SSD's I get scared that one day it will just go dead. Data gone. And they cost so darn much.
     
  15. nuckinfutz macrumors 603

    nuckinfutz

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    #15
    The drive doesn't die when you use up your write cycles it just becomes a read only drive.
     
  16. uberamd macrumors 68030

    uberamd

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    #16
    An insanely expensive read only drive. I have a SSD in my Dell Mini 9, and its nice. Quiet, can take a shaking, etc. But there are all kinds of rules when dealing with SSD's (at least there used to be). Turn off journaling, turn off Windows Drive Indexing, turn off access timestamp modification, etc. After reading that stuff, I just assumed they are very fragile in a data modification sense.
     
  17. Makosuke macrumors 603

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    #17
    You've got an overly optimistic view of how conventional hard drives fail.

    Yes, they often start showing issues like bad blocks or SMART errors or misbehavior, but it's quite possible for one to "just go dead." I've seen it happen in person, ranging from completely failing to power up, to a loud "click" and it's dead, to chips physically burning themselves up.

    In fact, the sort of failures that spinning HDs give you some warning with--which are largely mechanical, such as a failing motor--are the ones that SSDs shouldn't even suffer from, due to lacking those parts.

    Now, one potential difference is that if you're rich and/or desperate, there's a pretty good chance of an expensive data retrieval house of being able to extract data from a dead drive's platters, and while I don't know enough about SSDs to say anything for certain, it may be more difficult to deal with the same situation. But then, most of us don't have $5000 laying around for data retrieval, so that's arguably not even an issue.

    As for the lifespan, due in part to wear-leveling done by the drive's firmware it's way, WAY longer than people seem to think. This article explains how a more-reliable drive, lasting about 2 million write cycles (at 2008 capacities and speeds) could be constantly writing data at its max throughput and STILL last 51 years. This drastically more conservative article, based on a microscopic SSD of only 4GB with conservative 50% wear leveling and a reasonable lifespan of 100,000 write cycles would still last a year and a half if it were writing 4MB/s 24/7.

    A more realistic drive of, say, 128GB, using the same 4MB/s writes 24/7, 50% wear-leveling efficiency, and 100,000 cycles would last you over 50 years. Even if the life of the memory were a paltry 10,000, and most people are NOT writing 4MB/s through their drive at all times (that's 345GB/day), you'd get 5 years. And if the wear-leveling sucked horribly, the only side effect would be that the drive's usable space would shrink by about 1% every year.

    You can plug your own numbers for wear leveling, longevity, and write volume in and get different estimates, but the bottom line is in real-world use something in the drive is almost certainly going to fail before the write limit becomes any kind of issue, and in real world office-level use you would probably die of old age before it started to hurt.

    [Edit: Just to add a real-world use number, my main home Mac has averaged about 5.6GB written to disk per day, which includes at least 3GB of video saved, moderate web use, light development work, and a couple of software installs. Assuming relatively poor wear-leveling of 20%, a modest 128GB SSD, and a very conservative 10,000 write cycles, I could use my computer like that every day for the next 125 years before I'd notice decreased storage available. Heck, I could run that much data through the $21 8GB SDHC card for my camera and it'd still last 8 years. Increase that to 100,000 write cycles or significantly improve the wear-leveling efficiency and the memory cells in an SSD would likely outlast modern civilization (or, more likely, the physical materials that make up the circuit board).

    Point being, in normal use, NOT an issue. At all.]
     

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