Upgrade HDD to SSD on the 2017 27inch iMac Fusion Drive
Hi all,
I just thought I'd share my experience here in the chance it might help someone else.
After searching the web on this topic and getting conflicting answers, I ended up just going ahead and trying it myself.
I own a 2017 iMac 5K with a 1TB Fusion drive (1TB SATA HDD + 28GB PCIe SSD).
I wanted to upgrade the HDD drive to an SSD, but wasn't sure what to do with the PCIe SSD? Re-fusion the two drives? Seperate the two SSD's? Install OS on the PCI SSD?
Hardware used:
Crucial MX500 CT1000MX500SSD1(Z) 1 TB Internal SSD (3D NAND, SATA, 2.5 Inch) https://www.amazon.co.uk/dp/B077SF8KMG/ref=cm_sw_r_cp_api_6IATBbJ4XRPN0
Sabrent 2.5” SSD & SATA Hard Drive to Desktop 3.5” SATA Bay Converter Mounting Kit (BK-PCBS) https://www.amazon.co.uk/dp/B00UN550AC/ref=cm_sw_r_cp_api_XLATBbM6SYC86
All in everything cost me €187.
Before the installation of the new Crucial SSD the disk write and read speeds were around 850 MB/s & 1400 MB/s respectively.
These numbers seem impressive initially, but as these speeds are from the PCI SSD once we get through around 20GB's it switches to the slow ass mechanical HDD, speeds drop to about 100 MB/s Write & 150 MB/s read, far less impressive.
See these tests for similar results and some nice graphs: https://www.macworld.com/article/2017365/storage/lab-tests-pushing-a-fusion-driv e-to-its-limits.html
After the Crucial MX500 SSDv was installed, I ran Blackmagic Disk Speed Test and got 450 MB/s Write & 510 MB/s Read. This is clearly the new SATA SSD and nothing from the PCI SSD.
I then went and configured my new SATA SSD with the PCI SSD as a fusion drive and was happy enough with the results.
With the fusion configuration I get around 850 MB/s Write & 1400 MB/s Read for the first 20GB's roughly. Then 450 MB/s Write & 510 MB/s Read for the remaining 1TB.
Not bad for a €187 Euro upgrade.
One of the other questions that was bugging me was will I need a Thermal Sensor for the new SSD as required in previous models?
Well, to find out I decided not to install the Thermal Sensor and I've been running the Mac for a day or so now with no noticeable fan speed difference. Still as silent as it always was.
Note: In order to be guaranteed not to effect my apple warranty, I got an Authorised Apple Service Centre to change out the hard drive, which I had bought and cloned myself. Took 30 mins and cost an additional €75 at Mactivate Dublin, which isn’t bad for piece of mind.
Hi all,
I just thought I'd share my experience here in the chance it might help someone else.
After searching the web on this topic and getting conflicting answers, I ended up just going ahead and trying it myself.
I own a 2017 iMac 5K with a 1TB Fusion drive (1TB SATA HDD + 28GB PCIe SSD).
I wanted to upgrade the HDD drive to an SSD, but wasn't sure what to do with the PCIe SSD? Re-fusion the two drives? Seperate the two SSD's? Install OS on the PCI SSD?
Hardware used:
Crucial MX500 CT1000MX500SSD1(Z) 1 TB Internal SSD (3D NAND, SATA, 2.5 Inch) https://www.amazon.co.uk/dp/B077SF8KMG/ref=cm_sw_r_cp_api_6IATBbJ4XRPN0
Sabrent 2.5” SSD & SATA Hard Drive to Desktop 3.5” SATA Bay Converter Mounting Kit (BK-PCBS) https://www.amazon.co.uk/dp/B00UN550AC/ref=cm_sw_r_cp_api_XLATBbM6SYC86
All in everything cost me €187.
Before the installation of the new Crucial SSD the disk write and read speeds were around 850 MB/s & 1400 MB/s respectively.
These numbers seem impressive initially, but as these speeds are from the PCI SSD once we get through around 20GB's it switches to the slow ass mechanical HDD, speeds drop to about 100 MB/s Write & 150 MB/s read, far less impressive.
See these tests for similar results and some nice graphs: https://www.macworld.com/article/2017365/storage/lab-tests-pushing-a-fusion-driv e-to-its-limits.html
After the Crucial MX500 SSDv was installed, I ran Blackmagic Disk Speed Test and got 450 MB/s Write & 510 MB/s Read. This is clearly the new SATA SSD and nothing from the PCI SSD.
I then went and configured my new SATA SSD with the PCI SSD as a fusion drive and was happy enough with the results.
With the fusion configuration I get around 850 MB/s Write & 1400 MB/s Read for the first 20GB's roughly. Then 450 MB/s Write & 510 MB/s Read for the remaining 1TB.
Not bad for a €187 Euro upgrade.
One of the other questions that was bugging me was will I need a Thermal Sensor for the new SSD as required in previous models?
Well, to find out I decided not to install the Thermal Sensor and I've been running the Mac for a day or so now with no noticeable fan speed difference. Still as silent as it always was.
Note: In order to be guaranteed not to effect my apple warranty, I got an Authorised Apple Service Centre to change out the hard drive, which I had bought and cloned myself. Took 30 mins and cost an additional €75 at Mactivate Dublin, which isn’t bad for piece of mind.
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