Does my iMac (Retina 5K, 27-inch, Late 2015) that came with a hard drive, come with a PCIe slot?

According to macsales.com and others sources. Yes the 2015 27" iMac HDD model has a PCIe slot.

see > https://blog.macsales.com/30510-unboxing-and-teardown-of-the-2015-27-inch-imac-with-retina-5k-display/

The Late 2015 27" iMac Hard Drive model can also be upgraded to a 2.5" SSD using a specific HDD to SSD kit.

For the kit and video, see > https://eshop.macsales.com/item/OWC/K27IM12HP1TB/

As you can tell from the contents of the kit and the video, opening and upgrading an iMac is not something that just anyone can or should do.

A less expensive and invasive option, is to run just your 2015 27" iMac from an external Thunderbolt or USB 3.0 SSD.

see > https://eshop.macsales.com/shop/external-storage#drive-configuration:single-bay

I quote from an internet source

"All of the SSDs found in the Late 2015 iMacs are of the new PCIe 3.0 x4 variety, but the A1418 only supports a PCIe 2.0 x4 connection. The 27″ iMac, on the other hand, is the only device other than the 15″ MacBook Pro to support a PCIe 3.0 x4 connection. Both iMacs support the NVMe protocol though and can upgrade to later Gen. 5 SSDs for a big speed boost."

My late 2015 27" base model (came with only HDD) -- does have the PCI-e slot (mine is PCI-e 3.0 x 4)

I had 256GB PCI-e (pulled from my MacBook Air) installed on that iMac (it was white knuckle process) - however, I had to find a compatible screw to hold this 256GB PCI-e SSD onto the logic board.

The reason for this operation was -- dual boot system 1T SATA 2.5" SSD for Catalina, and 256GB PCI-e for Mojave (so I can still run some 32 bit softwares).

I can say, I really do not see much difference in terms of performance gap (for simple video editing/music editing) etc. from both SSD drives.

You should ask yourself, if PCI-e SSD speed is really essential for the upgrade, or internal SATA SSD/external SSD would satisfy your need without much hassles.

oxemanuelexo wrote:

is there any way that I could have a faster drive because I am doing tasks that needs a lot of speed from my drive

Only if you can DIY or find someone that is willing to dissemble the iMac and put a blade into the PCIe slot.

Shown with tools...

https://eshop.macsales.com/upgrades/imac-retina-5k-27-inch-late-2015-3.3-ghz/internal-drives

Install video showing how to get to it...

https://eshop.macsales.com/installvideos/imac-27-inch-5k-2014_15-pciessd/

Sorry, for some reason I had your 2015 iMac confused with a later iMac the had Thunderbolt 3.

A 6G SSD in a USB 3.0 enclosure will give somewhere between 450 and 520 MB/s. Which is not as fast as an internal PCIe, but still 4 or 5 times faster than your iMac's current HDD.

You will need to call around.

Apple Stores will generally not do those types of upgrades.

Some Authorized Apple Service Providers might, if they have access to the required parts.

Plus it is not going to be cheap. You actually might do better just selling that iMac and buying one that already has a PCIe.

Or just do as suggested above and run that iMac from an external Thunderbolt or USB 3.0 SSD.

If the answer to that specific question – "So how do I know if my iMac has a PCIe slot?" – is not forthcoming in your quest, I suggest you go with one of these options:

1. Take the advice given above and go with an external SSD as a boot drive and relegate the internal hdd to data storage status.
2. Take the iMac to an authorized service provider and let them open it and tell you if a PCIe connector is in place and can be used to install a blade ssd as an upgrade to the startup drive. Then let them do the work (or pack it up and DIY at home).
3. If you're inclined to DIY anyway, purchase the tools and open the machine to determine for yourself if a PCIe connector is in place. If so, then order the blade ssd and install it when it arrives in a few days OR, if no PCIe, then go ahead and order up an ssd to replace the internal hdd and be done with it.

By far, the easiest to do will be Option 1. You will gain the speed improvement that you're looking for and the trouble and downtime will be kept to a minimum.

In any case, pease make sure that you have a current backup of your system and data. Time Machine is recommended, but as options I would also recommend either CarbonCopyCloner or Super Duper!.

Yes ridiculously expensive.

I doubt any PCIe stuff is going to happen, but den.thed pointed out links about SSD internally.

If anyone can it would be MacSales.com (OtherWorldComputing). They certainly can tell you is your model is capable of such an upgrade and can give you a price to do the job.

You're gonna have to do a little of the legwork yourself, my friend.

You should call and talk to the folks at OWC/Macsales about this. I'm sure they can help you out.

The number is on the website that @BDAqua linked above. 🙂

Start with this link for repair and replacement guides and tools for your task:

iMac Intel 27" Retina 5k (Late 2014 & 2015) - iFixit