I have a late 2009 iMac 27" which I modified with a Fusion Drive.
A 250GB Samsung 840 EVO replaced the Superdrive and works with the original internal 1TB Harddrive.
The Performance is really good, but the Samsung SSD has a bug in the Firmware that decreases the performance of Files older than a year to below
30MB/s read/write.
Now Samsung released a "Performance Update" (Bootable CD) with which the firmware gets updated and all files are read & written once again to get rid of the problem.
http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/support/downloads.html
I tested this CD on my 2009 MacBook Pro with an 128GB Samung 840 EVO and it worked perfect.
On the iMac there are some problems.
1.) The iMac does not boot off an external USB Device anymore (which seems to be an intentional behavior by apple when the superdrive is replaced by a bootable device.
2.) rEFInd does not support LVMs with Yosemite which is sad, because Fusion Drive is based on it
http://www.rodsbooks.com/refind/yosemite.html
So I got 2 Problems:
How do I get an external Device beeing used as boot device (USB Superdrive, USB Liteon or USB Stick)
Does this firmware update work on a fusion drive (LVM) at all ?
And additional:
Is it possible to connect the ssd as an external usb drive and keep the existing LVM (to reconnect the superdrive internaly)
A 250GB Samsung 840 EVO replaced the Superdrive and works with the original internal 1TB Harddrive.
The Performance is really good, but the Samsung SSD has a bug in the Firmware that decreases the performance of Files older than a year to below
30MB/s read/write.
Now Samsung released a "Performance Update" (Bootable CD) with which the firmware gets updated and all files are read & written once again to get rid of the problem.
http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/support/downloads.html
I tested this CD on my 2009 MacBook Pro with an 128GB Samung 840 EVO and it worked perfect.
On the iMac there are some problems.
1.) The iMac does not boot off an external USB Device anymore (which seems to be an intentional behavior by apple when the superdrive is replaced by a bootable device.
2.) rEFInd does not support LVMs with Yosemite which is sad, because Fusion Drive is based on it
http://www.rodsbooks.com/refind/yosemite.html
So I got 2 Problems:
How do I get an external Device beeing used as boot device (USB Superdrive, USB Liteon or USB Stick)
Does this firmware update work on a fusion drive (LVM) at all ?
And additional:
Is it possible to connect the ssd as an external usb drive and keep the existing LVM (to reconnect the superdrive internaly)