12 Replies Latest reply: Jul 13, 2010 12:32 PM by cmosquera
cmosquera Level 1 Level 1 (30 points)
I've had an i7 iMac 27" for about a month now and it is the best computer I've ever owned. I recently bought a Crucial CT128M225 SSD drive which is rated highly and does garbage collection automatically at the drive level without requiring OS support of the TRIM command. This drive should not slow down as much as previous SSDs and even if it does, it is no big deal to restore the lost performance by cloning it using the excellent tools available for Mac and then restore it back since it will be a relatively small size of data. My plan is to put this drive in an FW800 enclosure and then boot off that interface. The System, Applications and Library Folders will be housed on the SSD, everything else such as the Users folder will be on the 1TB built in drive.

The obvious is that the FW800 interface will limit the maximum throughput of the SSD but I believe that it will not be a huge factor because of the near instant seek time (0.1ms). I'm not going to open the iMac because doing so would void Applecare, but I don't want to take it to an Apple Store and have to pay them to do it if it's not worth it.

Has anyone done this? How well/poorly will it work and if you ended up putting the SSD in the iMac's internal SATA interface, was there a drastic improvement compared to having it boot the SSD from a FW800 enclosure?


iMac 27" i7 Late 2009, Mac OS X (10.6.3)
  • Kappy Level 10 Level 10 (257,675 points)
    The limiting bottleneck will be the Firewire interface. You might as well just put any fast notebook hard drive in the enclosure. Notebook hard drives today are capable of higher throughput than a Firewire enclosure supports. This will be the same for any SSD. The fast seek time isn't that big a deal in terms of file transfer over the FW interface. If you really want the performance benefit of the SSD, then you need to connect it to the computer's internal interface.
  • cmosquera Level 1 Level 1 (30 points)
    I would agree with you completely if booting up accessed few large files but booting up accesses many smaller files so the higher the # of files being accessed the more the benefits of the SSDs almost non-existent seek time and much better random read speed will be apparent despite the slower interface. As far as transfer speeds, I will keep my home folder on the internal drive.
    I was just looking to see if someone had actually done it. I will post my results here as soon as I test it though.
  • Kappy Level 10 Level 10 (257,675 points)
    I'll be interested to see those results. My money is on the interface limitations rendering not much performance difference.
  • cmosquera Level 1 Level 1 (30 points)
    I'm booting from the SSD now. Bootup takes about double the time but application launch is definitely faster now. Was a little slow coming out of sleep (beachball for a few seconds) but after that everything is pretty quick. I think I'll leave it like this for a while. I DO agree with Kappy that the interface hinders the SSD. Here's the setup:

    OWC Elite AL Pro dual bay independent mode with:
    1TB Hitachi drive (this is an extra drive for random stuff all my data is on the internal HDD in the iMac.)
    128gb crucial CT128M225 SSD
    plugged into 8Gb 27" iMac via FW800

    I used Carbon Copy cloner

    Message was edited by: cmosquera
  • msbeezy Level 1 Level 1 (45 points)
    My suggestion would be to open it up and install the ssd into the imac.
    I did so and also did on my previous 24" and I got say it's actually REALLY easy.
    I could do a HD swap in 15-20 mins now after doing mine just twice and there is nothing that would indicate you ever had it apart...nothing.
    The toughest part (not really) is removing and installing (2) of the LCD frame screws (8 total) near those powerful magnets that hold the glass front on.They are annoying little buggers! that grab the screws off your driver. That's the toughest part..(not tough just annoying)
    The ram door cover DOESN'T have to come off and the glass front could even be removed with a couple of pieces (loops) of masking tape..locate at two top corners..a quick jerk to break the magnet's holds then slide up out of clips along chin.
    I didn't completely remove the lcd panel but if you slip it up out of the chin (unit laying on it's back) you can then access the lcd temp probe wire and lcd ribbon cable and then pivot/flip the lcd panel away from you..bottom up and stand it on it's top leaving the other connections intact.This give you access to the complete inside.HD removal is very easy..just remember to jumper the temp plug you remove from the HD plugin location. i used a small piece of clipped paper clip bent in a "U' and inserted into the two (there only are 2) locations in the plug...then but it all back together and enjoy the crazy ssd speeds, quietness and cooler operation.
    BTW my work was a little easier I suspect as I have the base stand off as I use a wall vesa mount so it lies flat on it's back.
    Ask any questions if you like.

    Message was edited by: msbeezy for spelling/grammar
  • cmosquera Level 1 Level 1 (30 points)
    msbeezy, you are awesome, great stuff but I'm not going to open it up my iMac. Not that I'm afraid to break it and void my warranty or anything like that but I won't open my iMac for the same reasons that I won't open up my Rolex Datejust or my Bentley (I wish). I do appreciate your input and I gotta tell you that it's pretty darn cool that they used magnets to hold the glass in place. Well, let's discuss the techie ramifications of opening it and compare the scenarios:

    There are a couple of different ways to approach the use of SSDs on the iMacs, these branch off of "to open, or not to open" and limited by the number of SATA ports that Apple has graciously provided :

    1. Open it up, risk breaking it and voiding the warranty.

    a. Replace HD and put the SSD in its place, giving you native SSD speeds and lighting fast access to boot and apps. This approach forces you to take your iMac's hard drive and install it in an FW800 enclosure which would limit the speed of access to everything else (iTunes, Movies, Downloads, data) to the FW interface.You could also get a 3.5" RAID-0 enclosure for dual SSDs which would be wicked fast (ideal if you get a pair of 512G for $3000 then anything else discussed here is non-issue)

    b. Buy an "Optibay" or a SATA>Slim Sata adapter and replace the Superdrive with the SSD, which would give you lighting fast SSD access as well as retain the fast access of the built in hard drive. You would then put the superdrive into an enclosure and you're done. This is only if you are willing to accept the trade off of having the useless hole on the side of the computer. (I won't.) + My wife would kick my a$$.

    2. Don't open up the iMac, put the SSD in an FW800 enclosure and boot it up this way, it boots up a little slower (30 secs) for me this way but it is quiet, uses less power and is still MUCH faster than the HD for application launch. Xbench gives my SSD on FW800 an overall score of 144, the built in HD a score of 71.47 and a "similar" 1TB 7200RPM Hitachi drive connected via FW800 gets a 62.79.

    Now here's the real kicker: Keep in mind that by doing #1a above you will get somewhat slower access to the typically large data such as movies, pictures, videos, iTunes music and downloads which DO benefit from the larger bandwidth of the SATA interface. I do wonder if the slowdown in data access is that substantial given the small difference between the built in SATA above (71.47) and the Hitachi on FW800 (62.79). I did find out that my SSD on the SATA interface gets about 230+ XBench score on Macbook Pros so I got a 144 so I'm not doing too bad. Factor in that I'm running the OS and apps which don't access huge files anyway so the 30% hit in potential performance gained by the SATA interface is even less.

    my .02.

    I don't think it's worth opening it, maybe later I'll change my mind.

    Apple, please give these guys an extra SATA port inside!
  • msbeezy Level 1 Level 1 (45 points)
    cmosquera you are absolutely bang on with your comments..

    I'll like to add the following..

    I do not for a moment suggest one to complete the ssd swap and not come clean should something go south and warranty be necessitated..that being said the boys at my local genius bar are reasonable and great guys and I would have to think if I were to explain what I had done and should the swap have no effect on a failure that they would honor any necessary repairs regardless..( I'd hope )

    What I did not include in my post is that I only run the 27" as a monitor source, having replaced my 24" ACD with this unit since it's the darndest bestest 27" monitor out there ! I tried a 30" ACD and a Dell U2711 and sent them both back...no comparison..and I luv the glossy screen too ! My main rig is my Mac pro in which I use 3 intel X25M-80G in raid stripe and connect to the iMac with a mini display to mini display only for that gorgeous high res screen..Avatar in bootcamp a real treat!

    So why install the ssd into the iMac...? Guess I got this bug and I just had to see the inside of this thing and see if it would work and experience the buzz..:) Oh and I wanted to try to quiet the (hd) fans down.

    BTW I wouldn't open my Submariner either..oh..and make mine a Veyron please..:)
  • cmosquera Level 1 Level 1 (30 points)
    I resolved ALL of my issues with booting up from the SSD attached to a FW enclosure. I was having a problem where it would take twice as long to boot up and it would hang after coming out of sleep. These problems were resolved by setting DIP switch #3 to off on the OWC Mercury Elite AL-Pro enclosure (your mileage may vary). My Xbench score is 147 on the FW interface which is OK given that I am not experiencing any other delays compare that to a 60ish score on the built in hard drive and I've got a winner. I guess it's not all that necessary to open up the iMac to experience the benefits of SSD after all. Kappy and MSBeezy, I thank you for your comments!
  • msbeezy Level 1 Level 1 (45 points)
    Sounds good..! Which ssd btw..I'm in the market for a new as my MBP Vertex 60 is tapped.The more I research/read the more confused I get..with the new sandforce 1200/1500 coming out...some say problems..some say problems with OWC...some say SLC on the way out..gheeze.
    I might just stay with good ole Intel x25m-160...dunno ?
  • cmosquera Level 1 Level 1 (30 points)
    I'm using a Crucial CT128M225 upgraded to ver 1916 of their firmware. It's got drive level garbage collection which should make up for the absence of TRIM in OS X. Time will tell.
  • leejo Level 1 Level 1 (0 points)
    msbeezy, I am going to do what you did! I am at the point of ordering the parts and am wondering where you ended up on the ssd drive choice. I am considering the optibay and putting the superdrive on the outside. Any sage advice would be greatly appreciated.


  • cmosquera Level 1 Level 1 (30 points)
    For the record, I returned the CT128M225 Crucial and ended up with an Intel X25M160 which works much better. The crucial drive was garbage.