Upgrades for iMac (Retina 5K, 27-inch, Late 2015)

[PeterGos]

Hi I am looking to do some upgrades to my iMac (Retina 5K, 27-inch, Late 2015) iMac17,1 Quad-Core Intel Core i5 3.2 GHz.
Want to upgrade the CPU and the SATA mechanical drive.

Can anyone tell me if the Intel i7-6700K is the fastest CPU you can put in this particular imac?
Can you put an i9 for example?
Is the speed upgrade from the i5 to i7 that noticeable?

Also is there any issues with the fans running all the time when you swap out the hard drive for an SSD on this model?

I have 1867 MHz dimms installed, is this the fastest ram I can use?

Thanks for all you help
Peter

 

[Zdigital2015]

Hi I am looking to do some upgrades to my iMac (Retina 5K, 27-inch, Late 2015) iMac17,1 Quad-Core Intel Core i5 3.2 GHz.
Want to upgrade the CPU and the SATA mechanical drive.

Can anyone tell me if the Intel i7-6700K is the fastest CPU you can put in this particular imac?
Can you put an i9 for example?
Is the speed upgrade from the i5 to i7 that noticeable?

Also is there any issues with the fans running all the time when you swap out the hard drive for an SSD on this model?

I have 1867 MHz dimms installed, is this the fastest ram I can use?

Thanks for all you help
Peter

The i7-6700K is the fastest that you can get for the Late 2015. The cost for those in any sort of new condition is between $350-$400, so it’s an expensive upgrade for a 4 year old machine. Look on eBay and you find a good deal, or even an off-lease PC that you can swap CPUs out.

You cannot put a 7th, 8th or 9th Gen CPU in this computer. While a Core i7-700K is technically possibly, I don’t know anyone who has done it...Apple’s EFI is most likely going to prevent that. The 8th and 9th Gens are not electrically compatible, despite using the same LGA-1151 socket.

The speed difference depends on the applications you run. The 6700K is faster overall with 4c/8t, but not necessarily a huge difference maker in day to day tasks the way the SSD will.

If you swap out the mechanical HDD for a 2.5“ SSD you should not have to worry about the fans going crazy. You also have a proprietary PCIe SSD connector in there that you can put in an Apple PCIe Flash Storage SSD and in some cases, a third party SSD using an adapter. There are threads on these forums that can give you all the information that you need. Also, see this article - https://beetstech.com/blog/apple-proprietary-ssd-ultimate-guide-to-specs-and-upgrades

There is no point in running faster SO-DIMMs, besides, DDR3-1866 DIMMs should be fairly cheap. I would recommend 32GB (4x8GB) which will set you back less than $200 and in some cases less than $150. Hope this helps. MacSales is selling a 4x8GB kit for $160.00 and Crucial for $198.99. You may find a cheaper price somewhere else, YMMV.

Good luck!

 

[redheeler]

Can anyone tell me if the Intel i7-6700K is the fastest CPU you can put in this particular imac?

Yes, it is.

Is the speed upgrade from the i5 to i7 that noticeable?

Depends on how you use it. If you do a lot of processor-intensive tasks like rendering video, it should be noticeable. But for basic everyday tasks there wouldn't be much of a difference.

I have 1867 MHz dimms installed, is this the fastest ram I can use?

I have 2133 MHz installed in mine, it works fine. Doubt you'd notice much of a difference though.

 

[_Kiki_]

I did some upgrades in mine about 2 years ago, I replaced i5 6600 for i7 6700k, I sold old CPU on eBay so the cost of the upgrade was about £100 (~$130), I replaced also 2TB HDD for 8TB HDD, so now I have 8.12TB Fusion Drive (I have 128GB proprietary Apple SSD), original 8GB memory was upgraded to 32GB DDR3 2133MHz Kingston HyperX

 

[PeterGos]

The i7-6700K is the fastest that you can get for the Late 2015. The cost for those in any sort of new condition is between $350-$400, so it’s an expensive upgrade for a 4 year old machine. Look on eBay and you find a good deal, or even an off-lease PC that you can swap CPUs out.

You cannot put a 7th, 8th or 9th Gen CPU in this computer. While a Core i7-700K is technically possibly, I don’t know anyone who has done it...Apple’s EFI is most likely going to prevent that. The 8th and 9th Gens are not electrically compatible, despite using the same LGA-1151 socket.

The speed difference depends on the applications you run. The 6700K is faster overall with 4c/8t, but not necessarily a huge difference maker in day to day tasks the way the SSD will.

If you swap out the mechanical HDD for a 2.5“ SSD you should not have to worry about the fans going crazy. You also have a proprietary PCIe SSD connector in there that you can put in an Apple PCIe Flash Storage SSD and in some cases, a third party SSD using an adapter. There are threads on these forums that can give you all the information that you need. Also, see this article - https://beetstech.com/blog/apple-proprietary-ssd-ultimate-guide-to-specs-and-upgrades

There is no point in running faster SO-DIMMs, besides, DDR3-1866 DIMMs should be fairly cheap. I would recommend 32GB (4x8GB) which will set you back less than $200 and in some cases less than $150. Hope this helps. MacSales is selling a 4x8GB kit for $160.00 and Crucial for $198.99. You may find a cheaper price somewhere else, YMMV.

Good luck!

THanks for getting back to me. So are you saying just replace the hd for a good SSD?

 

[Zdigital2015]

THanks for getting back to me. So are you saying just replace the hd for a good SSD?

If you’re going to spend the time and money disassembling your iMac to replace the CPU, I would Highly suggest adding a PCIe stick (preferably Apple SSUBX) in whatever you consider affordable (256GB or 512GB) as both are on the backside of the logic board. If you’re not feeling quite that adventurous, then you can easily change out the HDD for a 2.5” SSD (Samsung 860 EVO, Crucial MX500) in whatever capacity you can afford. The speed won’t go over 600MB/s, but that’s still a hell of a boost over the spinning rust in there now. Be sure to update your iMac to High Sierra 10.13.6 or Mojave at the very least before you do anything so that the iMac firmware is updated to a more recent version which helps when updating further revisions of the operating system. Good luck.

PS - Also search the “Sticky” forum posts for guidance on removing and replacing parts of your iMac.

 

[tommydlife]

Following as well too. You can get pretty inexpensive RAM on eBay or Amazon. I just bought a ATECH 16 (2x8) kit for 60. Once I install it, will report back here.

The SSD tips are interesting too. Its seems my SSD blade (part of the Fusion Drive) is dead on my computer so I'm only running on the SATA mechanical 2 TB drive.

 

[nambuccaheadsau]

tommy try separating the drives and see if the blade drive is actually dead. Back up first by ncloning as this willwipem the drives.

 

[tommydlife]

tommy try separating the drives and see if the blade drive is actually dead. Back up first by ncloning as this willwipem the drives.

Do you mean a physical seperation? Otherwise within Disk Utility (in regular boot and recovery mode) it's only detects the SATA drive. I've already tried the RESETFUSION command. What's interesting is that a week ago, under System Report ->SATA/SATA Express, it shows a SSD controller and SATA. Checking yesterday (while on the chat w/ Apple Support). It only showed SATA. Very strange behaviour indeed leading me to believe that the SSD blade is DOA.

 

[PeterGos]

Thanks so much for all your advice.
So just to recap. I think I am just going to swap out the mechanical sata drive for an SSD.
Is there any need to add a PCIe stick? Is it faster than a standard SSD?
Also if I change the mechanical drive for an SSD do I need to install the heat sensor cable?

Peter
[automerge]1571658561[/automerge]

If you’re going to spend the time and money disassembling your iMac to replace the CPU, I would Highly suggest adding a PCIe stick (preferably Apple SSUBX) in whatever you consider affordable (256GB or 512GB) as both are on the backside of the logic board. If you’re not feeling quite that adventurous, then you can easily change out the HDD for a 2.5” SSD (Samsung 860 EVO, Crucial MX500) in whatever capacity you can afford. The speed won’t go over 600MB/s, but that’s still a hell of a boost over the spinning rust in there now. Be sure to update your iMac to High Sierra 10.13.6 or Mojave at the very least before you do anything so that the iMac firmware is updated to a more recent version which helps when updating further revisions of the operating system. Good luck.

PS - Also search the “Sticky” forum posts for guidance on removing and replacing parts of your iMac.

Thanks so much for all your advice.
So just to recap. I think I am just going to swap out the mechanical sata drive for an SSD.
Is there any need to add a PCIe stick? Is it faster than a standard SSD?
Also if I change the mechanical drive for an SSD do I need to install the heat sensor cable?

Peter

 

[PeterGos]

The i7-6700K is the fastest that you can get for the Late 2015. The cost for those in any sort of new condition is between $350-$400, so it’s an expensive upgrade for a 4 year old machine. Look on eBay and you find a good deal, or even an off-lease PC that you can swap CPUs out.

You cannot put a 7th, 8th or 9th Gen CPU in this computer. While a Core i7-700K is technically possibly, I don’t know anyone who has done it...Apple’s EFI is most likely going to prevent that. The 8th and 9th Gens are not electrically compatible, despite using the same LGA-1151 socket.

The speed difference depends on the applications you run. The 6700K is faster overall with 4c/8t, but not necessarily a huge difference maker in day to day tasks the way the SSD will.

If you swap out the mechanical HDD for a 2.5“ SSD you should not have to worry about the fans going crazy. You also have a proprietary PCIe SSD connector in there that you can put in an Apple PCIe Flash Storage SSD and in some cases, a third party SSD using an adapter. There are threads on these forums that can give you all the information that you need. Also, see this article - https://beetstech.com/blog/apple-proprietary-ssd-ultimate-guide-to-specs-and-upgrades

There is no point in running faster SO-DIMMs, besides, DDR3-1866 DIMMs should be fairly cheap. I would recommend 32GB (4x8GB) which will set you back less than $200 and in some cases less than $150. Hope this helps. MacSales is selling a 4x8GB kit for $160.00 and Crucial for $198.99. You may find a cheaper price somewhere else, YMMV.

Good luck!

Do you mind if I ask your advice? After thinking about this more, if I bought an external ssd and stuck the os on it and booted from that, surely that would be the same speed as replacing the main drive, it would also save me the hassle of opening up the imac etc?

Peter

 

[Zdigital2015]

Do you mind if I ask your advice? After thinking about this more, if I bought an external ssd and stuck the os on it and booted from that, surely that would be the same speed as replacing the main drive, it would also save me the hassle of opening up the imac etc?

Peter

Get a quality UASP enable USB 3 enclosure and put in a quality 2.5” SATA SSD, like a Samsung 860 EVO and boot off of that. I use this enclosure - Vantec NexStar Gx USB 3.1 Gen 2 Type-C 2.5" SATA SSD/HDD Enclosure for 9.5mm & 7mm Height Drive; Comes with C to C and C to A Cable; Aluminum Casing; (NST-271C31-BK) https://www.amazon.com/dp/B072YLWP4Z/ref=cm_sw_r_cp_tai_pkWRDb05791JN - with a 2.5” 500GB Samsung 860 EVO.

The speed increase over the SATA HDD you have installed currently will be noticeable and worthwhile, even though you didn’t crack open the iMac and install it internally.

Other than doing that, I would invest in an additional 8GB or 16GB of DRAM, but no more unless you are planning on keeping this iMac for several more years (5+).

Just my 2¢.

 

[PeterGos]

Thanks for that.... think we are on the same wavelengths...

Get a quality UASP enable USB 3 enclosure and put in a quality 2.5” SATA SSD, like a Samsung 860 EVO and boot off of that. I use this enclosure - Vantec NexStar Gx USB 3.1 Gen 2 Type-C 2.5" SATA SSD/HDD Enclosure for 9.5mm & 7mm Height Drive; Comes with C to C and C to A Cable; Aluminum Casing; (NST-271C31-BK) https://www.amazon.com/dp/B072YLWP4Z/ref=cm_sw_r_cp_tai_pkWRDb05791JN - with a 2.5” 500GB Samsung 860 EVO.

The speed increase over the SATA HDD you have installed currently will be noticeable and worthwhile, even though you didn’t crack open the iMac and install it internally.

Other than doing that, I would invest in an additional 8GB or 16GB of DRAM, but no more unless you are planning on keeping this iMac for several more years (5+).

Just my 2¢.

Thanks for that. Would this be as fast as above? https://www.amazon.co.uk/gp/product/B074M774TW/ref=ox_sc_saved_title_3?smid=A3P5ROKL5A1OLE&psc=1

 

[Zdigital2015]

Thanks for that.... think we are on the same wavelengths...

Thanks for that. Would this be as fast as above? https://www.amazon.co.uk/gp/product/B074M774TW/ref=ox_sc_saved_title_3?smid=A3P5ROKL5A1OLE&psc=1

I just don’t care for the T5 personally, others here on the forums have had varying levels of success. It’s a tiny case with an mSATA module in there and I cannot believe the ventilation is all that good. The case I recommended has a USB-C connector, is all aluminum, comes with both a USB-A to USB-C cable, a USB-C to USB-C cable and its well ventilated. Pair that with a 1TB Samsung 860 EVO when they are on sale for $129.99 and its still less money than the 1TB Samsung T5 at Best Buy prices ($189.99). This does two things, it gives you a USB-C enclosure that can take a SATA HDD or SSD into the future and it allows you to swap out whenever you want versus mSATA, which is eventually going to go away before SATA drives do and it allows you to take the 2.5” drive and put that 2.5” SATA SSD into your iMac in the future if you should decide to rip it open, put in a PCIe blade, replace the CPU or just simply install the SSD to the internal SATA bay. Hope that helps.

Source (AnandTech T5 review and teardown): https://www.anandtech.com/show/11719/samsung-portable-ssd-t5-review-64layer-vnand-debuts-in-retail

PS - Sorry, just saw the co.uk link so I am quoting USD and not Pounds or Euros.

 

[tommydlife]

Following as well too. You can get pretty inexpensive RAM on eBay or Amazon. I just bought a ATECH 16 (2x8) kit for 60. Once I install it, will report back here.

The SSD tips are interesting too. Its seems my SSD blade (part of the Fusion Drive) is dead on my computer so I'm only running on the SATA mechanical 2 TB drive.

I installed the ATECH kit today and it's now humming on 24 GB ram vs the stock 8. No more swap file and memory pressure is green. If you use Ebay it's like 60 bucks and if you have an AMEX card, you can save 10 bucks.

 

[Mikebike125]

I have this same computer and am also looking upgrading my RAM. Currently I have 8GB in it and have been debating on getting 2x16GB tp add to my 8 for a total of 40GB which would cost around $305 plus tax or I can do the 4x8GB = 32GB for the roughly $200 talked about here. Do you think there will be a noticeable difference between the 32GB and the 40GB? Would say I am a "medium" user

 

[Mellow_Melon]

If you’re going to spend the time and money disassembling your iMac to replace the CPU, I would Highly suggest adding a PCIe stick (preferably Apple SSUBX) in whatever you consider affordable (256GB or 512GB) as both are on the backside of the logic board. If you’re not feeling quite that adventurous, then you can easily change out the HDD for a 2.5” SSD (Samsung 860 EVO, Crucial MX500) in whatever capacity you can afford. The speed won’t go over 600MB/s, but that’s still a hell of a boost over the spinning rust in there now. Be sure to update your iMac to High Sierra 10.13.6 or Mojave at the very least before you do anything so that the iMac firmware is updated to a more recent version which helps when updating further revisions of the operating system. Good luck.

PS - Also search the “Sticky” forum posts for guidance on removing and replacing parts of your iMac.

Can I ask for your advice, I have the same iMac 27 inch, late 2015 model:
If I were to add a PCIe Stick to the logic board would I also need to replace the HDD for an SSD?
I noticed I can get a good boost with a new PCIe, what would you recommend?

 

[ais5006]

I have this same computer and am also looking upgrading my RAM. Currently I have 8GB in it and have been debating on getting 2x16GB tp add to my 8 for a total of 40GB which would cost around $305 plus tax or I can do the 4x8GB = 32GB for the roughly $200 talked about here. Do you think there will be a noticeable difference between the 32GB and the 40GB? Would say I am a "medium" user

I just don’t care for the T5 personally, others here on the forums have had varying levels of success. It’s a tiny case with an mSATA module in there and I cannot believe the ventilation is all that good. The case I recommended has a USB-C connector, is all aluminum, comes with both a USB-A to USB-C cable, a USB-C to USB-C cable and its well ventilated. Pair that with a 1TB Samsung 860 EVO when they are on sale for $129.99 and its still less money than the 1TB Samsung T5 at Best Buy prices ($189.99). This does two things, it gives you a USB-C enclosure that can take a SATA HDD or SSD into the future and it allows you to swap out whenever you want versus mSATA, which is eventually going to go away before SATA drives do and it allows you to take the 2.5” drive and put that 2.5” SATA SSD into your iMac in the future if you should decide to rip it open, put in a PCIe blade, replace the CPU or just simply install the SSD to the internal SATA bay. Hope that helps.

Source (AnandTech T5 review and teardown): https://www.anandtech.com/show/11719/samsung-portable-ssd-t5-review-64layer-vnand-debuts-in-retail

PS - Sorry, just saw the co.uk link so I am quoting USD and not Pounds or Euros.

I just don’t care for the T5 personally, others here on the forums have had varying levels of success. It’s a tiny case with an mSATA module in there and I cannot believe the ventilation is all that good. The case I recommended has a USB-C connector, is all aluminum, comes with both a USB-A to USB-C cable, a USB-C to USB-C cable and its well ventilated. Pair that with a 1TB Samsung 860 EVO when they are on sale for $129.99 and its still less money than the 1TB Samsung T5 at Best Buy prices ($189.99). This does two things, it gives you a USB-C enclosure that can take a SATA HDD or SSD into the future and it allows you to swap out whenever you want versus mSATA, which is eventually going to go away before SATA drives do and it allows you to take the 2.5” drive and put that 2.5” SATA SSD into your iMac in the future if you should decide to rip it open, put in a PCIe blade, replace the CPU or just simply install the SSD to the internal SATA bay. Hope that helps.

Source (AnandTech T5 review and teardown): https://www.anandtech.com/show/11719/samsung-portable-ssd-t5-review-64layer-vnand-debuts-in-retail

PS - Sorry, just saw the co.uk link so I am quoting USD and not Pounds or Euros.

Looking to boot from External using the enclosure you linked. Is the EVO860 still the best drive to use? Any added benefit to new tech since that is compatible with this machine? Planning on adding new RAM too, and having this machine run well for another several years. It has gotten really slow on the stock drive and 8gb ram. Thanks in advance.