large memory for I Mac

AFAIK all the 2019 iMac models came with Fusion drives. Theoretically you could replace the internal HDD with a higher-capacity HDD or even an SSD but it would require a complete teardown of your iMac. That is not something for the typical user to do, as there is distinct risk of irrecoverably damaging the iMac.

While you could hire an Apple-knowledgeable repair service to replace the HDD, you would also be faced with having to reinstall macOS and all your apps, and assuming you have a backup, restore all your data.

IMO the best option is to get a good external SSD drive and connect it to your iMac. It supports both Thunderbolt 3 (up to 40 Gbps), and USB 3.1 Generation 2 (up to 10 Gbps).

For starters, consider an OWC Mercury Elite Pro, a Crucial X9 or X10 or Samsung T7 or T9 ... but 8TB isn't going to come cheap especially if it's an SSD. I like the OWC product; it holds 2 drives and includes a very good USB hub; for the price I think it can't be beat. I have a number of them with SSDs inside and they have been working perfectly for years.

My-Beautiful-Life wrote:

Can I put a 8TB SSD in a 2019 I Mac? I need more memory.

Do you need more memory or more storage? They are not the same thing.

According to MacTracker and Apple's Technical Specifications, the iMac (Retina 5K, 27-inch, 2019) was sold with a "1, 2, or 3 TB Fusion Drive, or 256, 512 GB, 1, or 2 TB flash storage." Replacing the internal drive or drives requires major surgery and is a job best left to a repair shop.

That Mac has four USB-A (USB 3.0) and two USB-C (USB 3.1 Gen 2, Thunderbolt 3) ports. You could use those to attach an external SSD without the need to pay a repair shop, or take the risk of performing surgery yourself. Note that 8 TB SSDs (or a pair of 4 TB SSDs) are not going to be cheap.

An 8TB SSD is not memory, it's storage. Memory is RAM and a 2019 iMac came with anywhere between 8GB to 32GB of RAM.

If you really want to upgrade RAM memory see the following link. If its 27" iMac its simply a matter of removing the rear hatch and installing new ram modules in the slots.

click here ➜ https://support.apple.com/en-us/108317

If you mean storage, you can install a hard drive of up to 4TB, but that requires completely disassembling the Mac, removing the screen, unplugging several very thin and fragile ribbon cables and installing a good quality SSD in place of the existing mechanical hard drive and totally forgetting about the Fusion Drive.

Good quality brands for SSDs include OWC, Samsung and WD.

You can search for good walkthroughs for upgrading the SSD or mechanical hard drive on your search engine of choice, but we can't discuss the process here sorry.

My-Beautiful-Life wrote:

Can I put a 8TB SSD in a 2019 I Mac? I need more memory.

Going price for an eight terabyte SATA 6 Gbps SSD looks to be USD$2500 to USD$3000 or so, plus installation.

An Apple authorized service provider will probably be willing to retrofit the SSD storage, though they’ll probably want to provide the (correct) SSD as part of the storage upgrade project.

Given the availability of Thunderbolt 3 on iMac 27” 2019, going external is another option, and with good performance.

Prices for a Thunderbolt NVMe 8TB is in the same price range as the SSD, and an external can be more easily transported to the eventual replacement Mac, given that this iMac has already fallen off current macOS support; is two versions back.

Or consider an external array, if you don’t need one big storage device, and either multiple smaller devices (“JBOD”) or a RAID array might suffice.

Might also want to update macOS to 15.8.2, too. Preferably before the end of January.

MrHoffman wrote:

Going price for an eight terabyte SATA 6 Gbps SSD looks to be USD$2500 to USD$3000 or so, plus installation.

If if doesn't have to be a SSD, an external desktop hard drive would cost a lot less.

OWC sells a preassembled 8 TB desktop hard drive for $680. On the B&H Photo Video site, I saw internal 8 TB hard drive mechanisms for $250 – $400+. You might be able to put one of those in a $59 OWC enclosure, for a grand total of around $425 – $450.

So, is this application one that really needs SSD speeds. Enough to justify $2000+ USD of extra cost? And has the OP considered the cost of the backup drive(s)? (The OP is planning on making backups, right?)

There is no need to install storage as an INTERNAL drive.

You can easily add an 8GB External drive in an enclosure, and not even muss your hair doing so.