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320GB striped array (RAID 0) in a Macbook Pro

:: Thursday, April 26th, 2007 @ 6:09:30 pm

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Macbook Pro with 2 drives installed

UPDATE: April 2009 Two Intel X25-M 160GB SSDs in striped array in unibody MacBook Pro

UPDATE: 28 Sep 2008 New benchmarks for striped SSD array in Macbook Pro.

Today, I installed an MCE OptiBay Hard Drive (a second 160GB 5400rpm drive) into my Macbook Pro. The directions that came with the drive were simple to follow, and it took about 15 minutes install (requiring the removal of 20-25 screws, plus two ribbon connectors).

When I booted back up, Mac OS X recognized the drive immediately (a SAMSUNG HM160JC) and asked me if I wanted to initialize it.

Instead, I rebooted from an external drive (backed up by the excellent SuperDuper) and created a striped RAID 0 array using the two internal Macbook Pro drives.

At this point, I discovered that you cannot partition a Mac OS X software RAID volume, so I was stuck with a single, 297.46GB volume. I back up my volumes with SuperDuper, and will just have to create scripts that backup a bootable system copy without images or video (and I’ll back up images/video separately, which is fine).

Shown here before the 2nd drive was installed. Installation requires the removal of 25 screws.

I ran Xbench on my system, and the results [download] are pretty impressive. My machine’s results are in the first column, compared to results of comparable configurations pulled out of the Xbench comparison site. The last column features benchmarks from a Mac Pro with a 250GB 7200rpm 3.5″ drive.

  Macbook Pro Core2
2x160GB 5400rpm
3GB / v10.4.9
RAID 0 (Striped)
Macbook Pro
160GB 5400rpm
2GB / v10.4.9
Macbook Pro
160GB 7200rpm
2GB / v10.4.9
Mac Pro Quad
250GB 7200rpm
4GB / v10.4.8
Seagate 3.5"
 Blocks Score MB/sec Score MB/sec Score MB/sec Score MB/s
Results 137.52 110.50 118.20 158.46 
Disk Test  67.08 36.37 42.94 69.46 
–Sequential 93.51 70.23 77.31 94.80 
—- Write 4K 163.43100.3469.6342.75 97.9960.16 70.5043.28
—- Write 256K 139.4878.9273.7941.75 86.3048.83 104.0558.87
—- Read 4K 43.6812.7857.3516.78 51.0314.94 100.6229.45
—- Read 256K151.5976.19 86.1743.31 96.5848.54 118.2259.41
–Random 52.30 24.54 29.73 54.80 
—- Write 4K 23.242.468.990.95 9.681.03 21.292.25
—- Write 256K100.0332.02 37.8312.11 83.3826.69 122.8539.33
—- Read 4K 71.240.50 66.160.47 89.590.63 93.700.66
—- Read 256K106.2519.72 98.1718.22 123.2322.87 138.6425.73

All reads and writes are uncached.

The results are impressive, except that the RAID 0 doesn’t seem to like small-block (4k) reads. Both sequential and random reads performed poorly. This should be fine, as I’m most often working with large images and video files.

screws removed during install

160GB 5400rpm drives are supposed to become much faster as they fill up. My drives are about 30% full, and I plan to re-run the test when they become more full.

MCE reports that the drive is supposed to shorten battery life on the system by 10-15%, but I haven’t had a chance to do my own tests.

As for sound, I can hear the 2nd drive now, spinning quietly on the right-hand side of the machine. It’s audible, but not annoying. The replacement drive chassis doesn’t have the same clip receptacles that the SuperDrive chassis has, so the keyboard top on my Macbook Pro no longer sits exactly flush on the right side. There’s probably a 1mm gap, which isn’t enough to really bother me.

1mm gap between keyboard and chassis on right side

Subjectively, the system feels more snappy, and I’m happy to have made the upgrade. I use up at least 20-30GB per week in the field, and it will be great to be able to work on my notebook without having an external drive chained to it.

Many people don’t like using RAID 0 arrays because they double the likelihood of catastrophic failure; I back up my data all the time — even when I’m traveling — so I’m not so worried.

Also see:


This machine is really much faster now. I just booted up Windows XP in Parallels, and it didn’t do the usual “take the computer down for a bit” routine during XP startup. It just booted, and was fast immediately after boot, as it is on my Mac Pro. Normally, the XP load process in Parallels slows my entire machine down as it struggles to pull data from the disk.

My Macbook Pro has always run hotter than my old Thinkpad did. Even when doing simple web surfing or writing e-mails, I can’t use the machine in my lap for long periods of time without putting a book or pillow between it and my crotch. It seems to run a bit warmer with the 2nd drive in, but it’s hard to remember, in comparison. The left palm area was always much hotter than the right (make sense — it’s where the main drive is); now the right side is also a bit warm — but nowhere near the warmth of the main drive area.

The metal strip above the keyboard is always hot, now. I don’t remember if this was the case before I put in the 2nd drive. It could also be because it has suddenly become warm here in the Bay Area. The temperature in my loft has gone up by a lot in the past two days.

The internal cooling fans do not run any louder or more often than they used to.


Some folks on the second Digg page are saying that it’s stupid to use RAID 0 in a computer, because there are “no real world benefits” and because it’s too dangerous.

I disagree. My machine is clearly running much faster, and it doesn’t seem to be running that much hotter. The fans still only spin up with high CPU usage. Battery life has always sucked on the Macbook Pro, and the estimates of losing 10-15% seems to be accurate so far. When I copy images onto the machine while in the field, they are simultaneously copied to an external volume for backup. Finally, I back up frequently onto bootable, external media, even when I’m on the road, so losing my internal volume wouldn’t be catastrophic. At home, my system backs up automatically to NAS every night. The only problem is that I would have to work off of an external drive, if the RAID failed. I’d have the same problem even if I wasn’t using RAID.

I used to use a Thinkpad T-series notebook, which was a great machine because it allowed the use of two hard disks at a time in a supported, modular way. I loved that thing.

Anyway, back to the topic at hand. I’d love to hear about the negative Digg commenters’ personal experiences with running RAID 0 in a notebook. I’ll bet none of them have ever done it, and are speaking without any facts to back up their claims.


Still going strong! I noticed that I now get bursts of up to 54MB/s when copying over gigabit from my Mac Pro (which is configured in RAID 1+0 over 6 disks). That is awesome.

—UPDATE, NOV 25, 2007—

I have had network copy bursts of up to 90MB/s to my Mac Pro via gigabit ethernet, and regularly sustain 65MB/s when copying large files. See a screenshot here. I can’t wait until solid-state drives come down in price. If compatible, I want to shove two of them into my computer and RAID them. :)

| Oakland, CA | link | trackback | Apr 26, 2007 18:09:30
  • danspeters

    Does this greatly reduce your spinning beach balls?

    I’ll be curious to hear about actual loss in battery life.

  • http://aviflax.com Avi Flax

    Very cool!

    BTW, your site’s a little hard to read in Safari, because items from your right-hand column are floating on top of the right edge of the main column.

  • http://echeng.com echeng

    Avi – this page looks fine in Safari v2.0.4, other than showing small gaps in the box headers.

  • http://www.reefpix.org James Wiseman


    Does this mean you can expect a cease and desist letter from Apple for posting a photo of the inside of your Macbook? :-)

  • Jeff

    No optical drive? Are you going to carry one around with you?

  • http://www.ruaux.net/ Craig Ruaux

    I’m sad to admit I had to spend a lot of time looking at your MacBook’s innards to establsh what was going on in there… Only when I saw the products name did I truly understand.

    I take it then that you’re not bothered by the loss of the optical drive. What’ll you do if you’re in the deepest depths of Fak Fak and a drive failure (or some other evil) requires you to reinstall the OS??

    Seems like a cool idea though.

  • http://echeng.com echeng

    Jeff – it shipped with a $100 USB/Firewire bus-powered SuperDrive that is both compatible with all Mac apps, and allows booting from CD/DVD(something that I guess is hard to find for Intel Macs). The enclosure is big and metal, and heavier than it should be, but — yes, I will travel with it when I think I need it.

    Craig – I back up my drive onto external, bootable drives. If something fails, I’ll just use the external drive for the remainder of the trip.

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  • Pat

    Could you post a picture of the keyboard? I would be interested to see exactly what I am up against, since I am planning on doing this as well. Thanks.

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  • Macinstein

    Hey Eric, do you always have to boot from an external drive to get up and running? I’m curious about how you did the RAID0 setup. I know OSX supports this as a software RAID setup, but can you then boot from the array too? If you could expand upon the procedure, I’d really appreciate it!

  • electroph4ge

    Interesting. You might also consider trying RAID 1. RAID 0 has better write performance than RAID 0 but RAID 1 has better read performance. I used to use RAID 0 on my desktop, but I’ve come to prefer RAID 1. I mostly process large scientific datasets, but the data is read much more often than it is written.

  • http://echeng.com echeng

    Macinstein: Yes, you’ll have to boot from an external drive to get RAID 0 working on your internal drives. But after that, you can boot from the array with no problems.

    electroph4ge: I needed RAID 0 because I need the disk space when I’m out in the field (I work as a photographer). Notebook drive capacities are not keeping up with my needs. :)

    I’ve also updated the post with an image of the gap between keyboard and chassis.

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  • Toby

    If you love disk space, have you considered that Drobo thing? It looks stunningly kickass and does it’s own RAID alternative which prevents dataloss, and if I had $699 to spare I’d own one in a heartbeat.

    Because it has to be hard burning DVD backups when you’ve removed the DVD drive :P

  • janderson

    I did the same upgrade in early March and ater a couple of weeks had the MCE-supplied drive go south. HOWEVER, removal and reinstallation of the MCE sled made it all work again. Then, another MCE-supplied drive failure occurred. So, I put another drive (purchased separately) into the MCE sled only to have the entire process repeat again. Temporary speed heaven followed by crashing hell. In EVERY case, the drives were fine when installed apart from the MCE sled. Ad yes, I have lots of experience inside Apple notebooks.

    MCE tech support was among the worst I have ever dealt with and after fighting and fighting with them, I finally got my money back. Heck, I even wanted another kit (realizing that this was likely a problem specific to my drive sled), but it apparently was not an option?! Perhaps they had some bugs to quietly work out?

    I miss the substantial speed increase. Good luck!


  • Fred Smith

    Worthy effort, but….. If sacrificing the optical drive weren’t enough, the drive causes the top of the case to bulge 1mm? Sorry dude… that’s a deal breaker.

    Raid0 sure is snappy, but you better back it up on a daily basis cause you’ve just doubled your chance at disk failure.

    Good luck!

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  • http://www.deepdreams.com Rogier Willems

    WOW now that’s a cool upgrade!

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  • http://geekfun.com eas

    I’m curious how it would have been just to have used the second drive as an independent disk and put the WindowsXP virtual disk files there.

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  • Felix

    Neat. I ran two WD Raptors (10,000 rpm drives) in RAID 0 for my System partitions on a desktop for a while and that was amazingly fast.

    I really don’t understand why you think you “need” RAID 0 for extra disk space out in the field. You aren’t getting extra free space, you’re just combining it all into a single logical drive. You could have the same amount of space with two separate drives, without the risk of one drive’s failure rendering all your of data unrecoverable – not a problem for, say, your OS partitions, but IMO, a really bad idea for storing your work/photographs. Like, Really Really Bad.

    Repeating for emphasis: “the risk of one drive’s failure rendering all of your data unrecoverable”

  • http://www.zibland.com Zib Redlektab

    The lid can still shut with the swollen keyboard, correct?

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  • http://www.microsoft.com heywood

    25 screws to install a hard drive? That’s almost as totally awesome as the “Mac Mini Tool Kit” they sent us when I was a tech at Best Buy a few years ago. Consisted of a dead blow hammer, a putty knife and a piece of sandpaper to sharpen it with. I shit you not.

  • Mike S

    Great piece Eric, I’ve been looking for something like this since the Optibay was introduced. I emailed MCE four times for info & never got a response…. I saw also that one other reader (janderson) had attempted this with unhappy results, Is your setup still running? How’s the heat?

  • http://web.mac.com/daniel.bargen/iWeb/Dan.Bargen.Portfolio/ Dan

    I’ve been considering going at this for some weeks now. I’ve got the same case you had with all of my photographs with Aperture on an external, so there’s no easy way to access my video and photo libraries without the external being plugged into the wall, car adapter, whatever. I know I could always back up the Vault system with Aperture, so going RAID with the two drives would be nice, but I’m worried about my other files too. I’ve got the last revision of the powerbooks, and I could REALLY use some more speed in Virtual PC when running AutoCAD and Architectural Desktop for work. Would you think I’d see similar improvements were I to do a RAID config? How much less of a performance gain do you think there would be if they were two separate drives?

    I’ve talked to MCE about this, but I’m still waiting on answers. Since the ppl here seem well-versed in drive performance, any suggestions would be appreciated. Thanks!

  • http://miamipartyboats.com MPB

    Whenever I take apart my laptop I always lose some of the screws, no matter how careful I am! And it never seems to go back together totally right, either.

  • http://echeng.com echeng

    Mike – setup is still working like a champ. The heat isn’t that bad; I don’t even notice it anymore.

  • http://12feet.blogspot.com Chris in Emeryville

    Hi Eric,

    Would you consider upgrading my MacBook Pro for me. I’ll pay you to do it!

  • http://www.mikebenner.com Mike Benner

    Do the drives have to be identical or can I use two different brands as long as the RPM and GB are the same?

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  • A.Carl

    You should mention in your “review” that MCE Optibay is only for PATA disks. Good thing to remember since most new 2.5″ HD is SATA with a totally different connector. My MCE Optibay didn’t fit my new WD 320GB 2.5″ HD… :(

  • Ben Lanois


    Do you think this is possible with 7200rpm drives? I’m a noob when it comes to SATA/PATA, etc., so I don’t even know if 7200rpm exists in the format the drives need to be for RAID 0. I currently have a 7200rpm Seagate drive in my computer – Would I have to switch it out in order to install two drives as an array?



  • http://echeng.com echeng

    Ben – I don’t think it is unless you go with 100GB drives. As A.Carl said, above, the 2nd slot is PATA. As far as I know, there are no 7200rpm PATA drives larger than 100GB in capacity.

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  • Mark

    i have the new macbook pro (2nd) gen if you will the one that came out october 14, 2008 and i want to do this! i already took out the 250gb hdd and replaced it with a WD 500gb Scorpio Blue, i now want to take out the optical dvd superdrive and install an other WD 500gb HDD, if anyone could guild be on what i need EG: like connectors cables and just general help i would be willing to pay 20$ on paypal! thank you

  • http://echeng.com echeng

    I just updated to two Intel X25-M 160GB SSDs, striped. 530MB/s sequential read!

  • Vlad

    hey , I am about to perform this mod on my macbook pro (feb 2007) but through an optical drive caddy from NEWMODE . I plan to put a Seagate 7200 500gb Sata in the caddy which has an sata to pata interface. That should work, right? And another thing : Do you think the second hard- drive could be connected to the pci express port (internally) ?


  • tzakrajs

    I dont know about you, but I use an external drive as my Snow Leopard Installer.

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