As you probably know , the MacBook Air use ostentation storage rather of the hard drives found in every other Mac . And while the initial solvent using our Speedmark 6.5 mental testing cortege showed that the Air ’s flash storehouse helped provide a performance boost , we were concerned about whether that performance could be keep up over time .
firm state drives ( SSDs ) and shoot storage ( Apple does n’t call the Air ’s photoflash - based storage an SSD ; it does n’t use a 2.5 - inch hard drive housing like a conventional SSD ) offer a number of advantage . Compared to hard drive , flash - establish storage perform faster . And since it lacks moving parts , flash - based storage is more shock resistant and not prone to the mechanical failings that hard private road are susceptible to .
The obvious downside are that flash - base storage machine are much more expensive from a price per GB perspective , and they offer lower memory capacities .
Not so obvious , however , are the performance issues . The single data cellular telephone on an SSD have a finite number of times that they can be written to , so manufacturers often admit wear - leveling technology to increase the life of the flash memory . Also , write performance can suffer when SSDs start to fill up over sentence . Some SSD manufacturer use over - provisioning manoeuvre — setting aside some capacity aside from the substance abuser to swap for bad blocks and backcloth tasks . Some SSDs offerTRIM , a way of handling some of the trash direction duties that can also slow down write speeds , but TRIM is n’t support by Mac OS X.
When shopping for an SSD , you’re able to usually read about the variety of engineering the manufacturer uses . Apple , on the other hand , does n’t really talk in item about its behind - the - scenes strategy for conduct with newsbreak memory ’s shortcoming . That can make masses like me nervous — especially in a scheme like the MacBook Air , where the flash memory is not exploiter replaceable . ( Sites like iFixit showhow to spread out up a MacBook Air and get to the flash storehouse , but such a task voids your warranty . )
Flash storage torture tests
To regain out how Apple ’s flash depot performs over the foresightful catch , we put three Macs that habituate flash memory for primary repositing through a torturous curing of trial run . We hunt down theAJA System Test , ourSpeedmark 6.5disk tests , and diglloydTools’DiskTesterFill bulk tests on a 2008 2.13GHz MacBook Air with a 128 GB SSD , a built - to - order 2010 27 - inch 2.93GHz musculus quadriceps femoris - sum Core i7 iMac with a 128 GB SSD , and a 2010 13 - in 1.86GHz MacBook Air with 256 GB flash storage .
The baseline result for the iMac and 2010 Air were similar . The average resultant role from three trials are listed below .
AJA System Tests : understand
AJA System Tests : compose
DiskTester Fill Volume : Read
DiskTester Fill Volume : Write
Duplicate a 1 GB file
After get those service line results , we erase and reinstalled OS X and migrate our information from a Time Machine computer backup . We then used DiskTester to pen 2,000,000 8 K files , erased the files , and ran the test again . Then we erased and reinstall OS X and information from a Time Machine backup , and twice ran another torture psychometric test , diglloydTools’MemoryTester . After that , we efface the flash storehouse and reinstall OS X and restore via Time Machine .
We ran our bench mark tests again and found that , unlike some of the SSDs we ’ve tested in the past , performance was unaltered . Despite all of the wiping , fill , strain , and imaging we ’d done on these poor flash storage devices , they do identically to the agency the had before being tortured .
We took the examination a little further to see how performance was dissemble when a storage machine was near full capacity . I filled the 256 GB ostentation computer memory in our 2010 1.86GHz 13 - column inch MacBook Air until there was just 5 GB of remaining space uncommitted and work the AJA arrangement trial and file duplication test . imposingly , the results did not show any execution debasement .
One hiccup
The newsflash storage in one of our 2010 Airs , a 13 - inch model with 128 G , stopped work properly before we were able-bodied to finish up the tests . It betray three - quarter of the way through our final OS ten instalment project . We adjudicate restoring from the admit USB flash drive and from a retail Snow Leopard saucer . No go . I boot from an outside drive and usedSuper Duperto clone a work Air figure , but it still failed to finish . I ran Disk Utility ’s Repair Disk on the flash repositing , but it did n’t find any problem with the ride . Other times , the drive would bomb to unmount . Many hour were spent , but in the end we resolve to adventure the health of another novel Air , the 256 GB 1.86GHz 13 - inch model cite in the results above , which had no problem completing these same tests .
Seeing how three of the Mac flash drives made it through the testing with take flight colors , I ’ll adopt that the one that stool out was a fluke . We ’ll keep testing and will let you get it on if this turns out to be anything more than that .
[ James Galbraith is Macworld ’s science lab film director . ]
