2012 11" SSD sudden slow down

Discussion in 'MacBook Air' started by hypercard, Jun 23, 2012.

  1. hypercard macrumors newbie

    Jun 23, 2012
    I got my new 2012 MBA 11" (i5, 128GB TS128E Toshiba SSD, CTO 8GB RAM) on Thursday - wonderful, speedy little machine.

    Since I read fantastic things about the SSD speed of this years model I was curious about the speed of mine and one of the first things I did (after a clean install which I always do with new Macs) I tested it with "Blackmagic Disk Speed Test" from the Mac App Store


    and - boom - I got indeed the reported 360 MB/s write and 460 read MB/s read speed and was thrilled. But after a few iterations (the disk speed test runs in a loop) the write speed suddenly dropped to 220-260 MB/s and has stayed there ever since.

    I clean installed (boot from recovery partition, wiped/repartitioned the disk, reboot/reinstall with internet recovery) the machine twice since (and also did a PRAM and SMC* reset) - the speed test never ever reaches over 300 MB/s in the write test again (read speed stays the same) - I'm frustrated.

    Especially since the speed was initially there I've got the impression that there's something "broken".

    Funny thing is, the first test with the never again reached write performance - even was on battery power :)

    I haven't called AppleCare yet, but I imagine they wont discuss SSD speeds (measured with 3rd party tools) - since their marketing specs just say "up to twice as fast" as previous years model - but I'll give it a try.

    What speed results do you get, fellow 2012 MBA 11" owners?

    Any ideas or suggestions other than to return it?

    * [Regarding the SMC reset, I'm assuming the method described under "Resetting the SMC on portables with a battery you should not remove on your own" is still valid for the 2012 Airs: http://support.apple.com/kb/HT3964
    I find the SMC reset procedure unfortunate, because there is neither described for how long the keys should be pressed, nor is there any confirmation of the action on the machine (that I would be aware of).]
  2. jgc macrumors regular

    Feb 21, 2012
    I have the same thing as well -- struggles to even register to 250 MB/s write. Usually I get 225 write/460 read. I have a feeling it's just the SSD. I have the base 13" with 8 gb RAM and a Toshiba drive.
  3. mixman macrumors member

    Aug 3, 2011
  4. Beau10 macrumors 6502a

    Apr 6, 2008
    Downtown San Diego
    Guess I should register my "me too" on this one, got in the 350 range on writes the first 3-4 times then it dropped down about 100. Toshiba 128.
  5. wharzhee macrumors 6502

    Apr 27, 2010
    Ssd hard disk aren't meant to be written on continuously. They are good for reading, and you should retrain from writing on them for no good reasons. Such as formatting your hard disk every month.

    Using the bench test continuously(sorry to say) is stupid. Cause it tends to write and over exert the ssd. And ssd hard disk wears and tears, and do slows down eventually after numerous writes.

    People usually use a good sized ssd hard disk for the OS, and a large sized spinning hhd for data keeping.
  6. hypercard thread starter macrumors newbie

    Jun 23, 2012

    Then how would you benchmark it, or does performance not matter to you?

    As for the duration of the test, we're talking a few minutes, not hours, here - any copying of data from your old Mac would mean more stress to the SSD.

    I get the impression that Apples custom SSD firmware does something here - for whatever reason.
  7. dmelgar macrumors 68000

    Apr 29, 2005
    Count me in on experiencing this as well and not being happy about it.

    One of the most important aspects of the MBA is having fast SSD. I'm upgrading from a 2010 MBA so I was hoping for faster SSD.

    From that I can tell, it looks like its a Toshiba vs. Samsung SSD issue (again).

    The 256GB drives seem to be Samsung. I had an 11" ultimate and it benchmarked 425/450. Awesome numbers. And consistent.

    As the OP says, then I received this base 13", I was pleasently surprised to see 365/450.

    I upgraded to Mountain Lion. Apparently that was enough disk activity to kick it into low gear. Now getting 240/445. And the 240 is being generous.

    It doesn't seem right to drop that much for no reason. Its almost as if they built in a benchmark fudge factor. Get a new machine, try it out, get impressed with 365MB/sec. But actually use it and its only 240.

    I cant think of a rational explanation for the dramatic performance drop. It doesn't seem plausible to have such a drop be needed. The initial benchmark is very misleading.

    Has anyone been able to restore the original speed. Could this be a defect, possibly a software defect in the SSD?

    Is there any discussion of this on the Apple support forums?
  8. mober macrumors newbie

    Jul 9, 2012
    even though I don't have the toshiba ssd, but the 256 samsung one, I ran a test with the app you mentioned for comparison reasons... here's what's going on on my machine.

    mba 2012
      Capacity:	251 GB (251,000,193,024 bytes)
      Model:	APPLE SSD SM256E                        
      Revision:	CXM09A1Q
    du -hs /
     37G	.

    Attached Files:

  9. hypercard thread starter macrumors newbie

    Jun 23, 2012
    yes, i opened the same thread over there:


    sadly with the same results: some guys reporting the same problem and that's it essentially...
  10. mikkker007 macrumors member

    Jul 12, 2012
    Queensland, Australia
    At the end of the day.........who cares?.... if you're happy with the machine and its doing what it says on the box....... wheres the issue?? when I put my foot down, i don't care if number 7 cylinder is a little down on compression..... its "within" normal tolerance's .... and..... I'm still accelerating...... chill out... enjoy one of the best machines on the planet......
  11. kodeman53 macrumors 65816

    May 4, 2012
    Sadly, there are some people whose OCD prevents them from enjoying anything because they can't rest until they find a 'flaw' then they can't rest until they share it with everyone else. Also sad are the people who believe them. The huge Samsung v LG thread is a perfect example of much OCD ado about absolutely nothing.
  12. KPOM macrumors G5

    Oct 23, 2010
    My guess is this has something to do with the SandForce controller's garbage collection routine and that it can be corrected with a software update (or perhaps will work out over time as the SSD's GC routine does its thing).

    In the meantime, don't worry about it. It would be great if Samsung saw itself primarily as a supplier rather than competitor of Apple, but that isn't the world we live in. As long as that is the case, Apple will use multiple suppliers.
  13. pankajdobariya macrumors newbie

    Jul 11, 2012
    In the meantime, don't worry about it. It would be great if Samsung saw itself primarily as a supplier rather than competitor of Apple, but that isn't the world we live in. As long as that is the case, Apple will use multiple suppliers.
  14. dmelgar macrumors 68000

    Apr 29, 2005
    It is a big deal.
    Folks overly fixate on CPU speed. With a MBA, the SSD speed is a major part of the performance of the machine. This isn't a cosmetic imperfection, it's a major hit to the machines performance.

    How would you like it if your 2.0ghz CPU benchmarked as 2.0ghz when you first got it, then an hour later suddenly benchmarked as 1.3ghz from then on.

    I'd guess people would be upset. Folks pay an extra $100 for a measily 0.2ghz speed increase and here we have a sudden 33% drop in disk write speed.
  15. dmelgar macrumors 68000

    Apr 29, 2005
  16. dcorban macrumors 6502a


    Oct 29, 2007
    Synthetic benchmarked write speed.

    When your real-world file saving and copying starts taking 33% longer, let us know.
  17. dmelgar macrumors 68000

    Apr 29, 2005
    I don't know why you think there something magically "synthetic" about this benchmark. The results seem consistent with actual performance.

    My initial install of Mountain Lion went much faster than the 2nd install. After the 1st install it was still benching 360MB/sec, but after the 2nd it was 240MB/sec.

    My theory is that maybe its fast on the initial write. But once its written it has to erase then write. In any case, 240MB/sec seems to be the actual mark, much slower than the Samsung.
  18. magbarn macrumors 68000

    Oct 25, 2008
    Since once again we have to playing the Apple OEM source lottery, are all the 128gb this craptastic Toshiba drive? Thinking about getting a MBA 11 128 model and will likely upgrade to 256gb to avoid this crappy sandforce drive (Hate sandforce on the PC side as well, too many failures)

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