How to improve iMac 5K 2017 overall performance?

Hi, I work as IT manager for several years now and I also have worked for an Apple service provider back in 2001. I currently have many iMac 5K from 2015 to 2017 models in my business design department where my graphical designer are complaining that these machines are unresponsive, slow and often "hang" in Photoshop, AfterEffect, Premiere, etc. All my iMac 5K are pretty much the same models, they are the middle range i5 model, with 16 GB RAM and the factory 1 TB FusionDrive which is supposed to be as quick as a real SSD according to Apple...

I am now trying to figure out what could be my options to "boost" up my iMac 5K the most that I can, but I am not sure where exactly are the "Bottleneck" of them actually, is it the Fusion drive? Can I replace the Fusion with a fast full SSD drive? I am just don't sure what (physically) the Fusion Drive is exactly, since I already taken appart lot of 2012+ 27in iMac, but never one equipped with the Fusion. Is it a 2.5 SSHD or is it something like a standard 7200 RPM HDD with a M.2 SSD on the side that are part of a logical volume group?

Then, do you think that upgrading to 48 GB RAM could be a must (keep factory 2x8GB and add 2x16GB aftermarket)?


Thank you very much!!

The memory and fusion drives are your bottleneck. The Fusion drive is exactly what you said with "Is it a 2.5 SSHD or is it something like a standard 7200 RPM HDD with a M.2 SSD on the side that are part of a logical volume group?". It's marketing from Apple and ultra crap.

You will see HUGE benefits replacing that with a standard SSD.

Next, for any serious photo/video work, 16GB of memory is not sufficient. You need to be at least at 32GB (48GB is even better).

Just those two things will breathe new life into these machines.

Raz0rEdge said:

The memory and fusion drives are your bottleneck. The Fusion drive is exactly what you said with "Is it a 2.5 SSHD or is it something like a standard 7200 RPM HDD with a M.2 SSD on the side that are part of a logical volume group?". It's marketing from Apple and ultra crap.

You will see HUGE benefits replacing that with a standard SSD.

Next, for any serious photo/video work, 16GB of memory is not sufficient. You need to be at least at 32GB (48GB is even better).

Just those two things will breathe new life into these machines.

Click to expand...

I just found a interesting take apart video on YouTube where I can finally see the Fusion drive in parts, which is obviously a standard 3.5 HHD + a M.2 SSD.

The remaining question is, do you think I need to take EVERYTHING appart, like remove the entire motherboard in order to get access to the M.2 SSD and remove them or do you think I can leave it in place and somehow disable it or just don't use it?

I did the upgrade on my 2009 iMac from HDD to SSD which was very straight forward. But I don't have experience/knowledge on the 2017 model. If you didn't want to pull out the SSD, just disconnecting power to it should be fine to "disable" it. You'll want to replace the HDD with the SSD and use those cables (guessing, not having seen the teardown).

Raz0rEdge said:

I did the upgrade on my 2009 iMac from HDD to SSD which was very straight forward. But I don't have experience/knowledge on the 2017 model. If you didn't want to pull out the SSD, just disconnecting power to it should be fine to "disable" it. You'll want to replace the HDD with the SSD and use those cables (guessing, not having seen the teardown).

Click to expand...

Thanks but I think you mis understood my question. I am actually talking about replacing the Fusion Drive by a SATA SSD. As for the "flash" part of the fusion, it's actually a small M.2 SSD (or maybe it's a PCIe SSD, anyway...) that is located UNDERNEATH the motherboard and that is not accessible without completely removing the motherboard, so that imply to remove the power supply, heat sink, speakers, all wiring harnesses, etc., in fact it's a 100% take appart of the iMac 5K to reach the M.2 SSD portion of the "Fusion" drive. Since this M.2 SSD is a circuit board inserted into a slot on the logic board, there's no separate power on it I can pull or something. So if I left in it place, I think that the disk manager will show a tiny SSD drive in addition to the large SATA SSD drive I'll put in place of the rotating HDD. I don't know if I leave the M.2 SSD disk "unformatted" if MacOS may constantly prompt for a new drive and ask to initialize in the Finder... that's my point! This M.2 SSD is obviously useless because I think it's something like a 64 GB SSD or something that much tiny and I also want to avoid showing multiple local drives on the Finder desktop... it's just annoying.

*EDIT* : The SSD part of the Fusion drive is 25 GB... so it's VERY useless.

I see no reason you can not do what you want and just do not install the OS or anything else on the 64gb ssd. I am going to find some instructions for your machines and will post the URL later.


Also Photoshop is a real memory hog when doing complex work so the more ram you can give it the better.

I am going to find some instructions for your machines and will post the URL later.

Click to expand...

Not meaning to butt in or interfere, but ifixit.com and macsales.com should have videos for replacing drives etc. and even selling what one needs.


- Patrick
======

https://www.ifixit.com/Device/iMac_Intel_27"

Great repair guides for just about all Apple/Mac products.


Bob -

Sent from my iPad using Mac-Forums

All my iMac 5K are pretty much the same models, they are the middle range i5 model, with 16 GB RAM and the factory 1 TB FusionDrive which is supposed to be as quick as a real SSD according to Apple...

Click to expand...

As already posted, Photoshop and video work require lots of power. An i5 CPU can handle it, albeit slowly. You really need an i7 and probably lots more memory. And like Ashwin stated, Fusion drives are pure propaganda from Apple.

As for removing that small 25GB SSD, it's not worth the effort since you would need to completely disassemble the machine. Once the HHD is removed and replaced by an SSD that will break the "Fusion". You can then leave the small SSD in place. It will likely show up in the Finder but can be easily hidden from the desktop.