OWC 16GB PC19200 DDR4 2400MHz 260pin SO-DIMM Memory Ram Upgrade Compatible with Mid 2017 iMac 27 w/Retina 5K Models and Compatible PCs (OWC2400DDR4S16G)

I have a mid-2017 iMac 27 inch Retina with the 4.2 GHz Intel i7 with 2TB Fusion DriveINITIAL PROBLEMS (All Resolved):FiIRST PROBLEM: Replacing the 32gb memory with 64gb, the Mac initially didn't boot.I had to put my old memory back, boot it up, then try different configurations where I would keep original 16gb memory and place new 32gb making a total of 48gb. First time didn't work. Put the two sticks aside, and put the other two sticks in. Success! I now had 48gb. But, the system was slow as snot and took a long time after logging in. Now, I shut it down, removed original memory and moved 32gb upgraded memory to position 1 and 2 and put the sticks that weren't working in position 3 and 4. Finally, booted up! 64gb memory!SECOND PROBLEM: As mentioned everything was slow. I now had 64gb memory, but everything was slow but not as slow. Once I had mouse movement, I immediately removed the cache files in the library folder. Then I started opening up the apps that I use the most, first. With Fusion Drive, it uses a large cache to make opening apps a lot faster. The Fusion Drive is a mix of Flash or SSD and HDD. After using it for 4 hours and rebooting once everything became quite snappy and by the second day, I can finally see the payoff of having 64gb of memory.I have experienced issues with memory not allowing computer to boot up before, even in Windows. Sometimes memory sticks just have to be put in a specific order and no one knows that until they try. Most of the time, no issue.The GOODSo far, I am no longer needing a swap file. The responsiveness of apps and loading data is noticeably faster. This is a cheap upgrade that adds immediate benefits and well worth the money. More memory gives the system more headroom to work with.I was considering buying an M4 MacMini to replace this 2017 iMac because I felt it was important to have the speed and memory to tackle whatever tasks I need to plow through. Adding the memory changed that decision and helped to extend the life of this machine for another few years. I would rather save the money and use what I have.If you are on the fence, just do the upgrade. You will notice a difference and it will give your Mac new life. I only feel bad that I didn't make this choice years ago, or when I first bought the Mac. Of course, back then, the cost was double than what it is now.

Works perfect in my Precision 7520

LLEGO LOS QUE ESPERABA Y FUNCIONA MUY BIEN

Justo lo que necesitaba, quiero resaltar lo rápido que llegó este producto a Colombia. Excelente!

This was a direct install for a 2017 iMAC 27" (18,3) computer. I had 8GB installed from the factory and i've noticed that the computer has been going slower each year. When i ran the activity monitor on the OS, i saw that the computer was doing memory swapping (having to actively "put data back to the HD to free up space to run current processes) the system said that 6 of the 8 GB were always being consumed.This is an inexpensive upgrade. it still starts up slow (because it still have to pull data from the HD during Startup) but now once its up and running, all my programs perform faster. the system shows that im using about 10GB constantly so it still has plenty of room to keep lots of applications running without having to swap to the slower IO's of a hard drive.

Since I installed 2 more rams of memory in my iMac (Retina 5K, 27-inch, 2017), it now periodically just crashes. I have the error report but it means nothing to me. I assume my issue is related to this installation. Would anyone have any suggestions?panic(cpu 1 caller 0xffffff801d7198aa): [iokit.IODMACommand]: element modified after free (off:24, val:0x0000010000000000, sz:120, ptr:0xffffffa4c5c14e10)24: 0x0000010000000000Panicked task 0xffffffa991ae79f0: 7 threads: pid 2319: com.apple.WebKitBacktrace (CPU 1), panicked thread: 0xffffffae57bf2000, Frame : Return Address0xffffff80c9a3abd0 : 0xffffff801ce81c8d0xffffff80c9a3ac20 : 0xffffff801cfe15960xffffff80c9a3ac60 : 0xffffff801cfd09630xffffff80c9a3acb0 : 0xffffff801ce21a700xffffff80c9a3acd0 : 0xffffff801ce8205d0xffffff80c9a3adf0 : 0xffffff801ce818160xffffff80c9a3ae50 : 0xffffff801d7151630xffffff80c9a3af40 : 0xffffff801d7198aa0xffffff80c9a3b3b0 : 0xffffff801ceeb8a90xffffff80c9a3b410 : 0xffffff801d64f4970xffffff80c9a3b440 : 0xffffff801d64cc510xffffff80c9a3b4a0 : 0xffffff7fb5dea8570xffffff80c9a3b4c0 : 0xffffff7fb5dfc9fb0xffffff80c9a3b510 : 0xffffff7fb5da92bd0xffffff80c9a3b530 : 0xffffff7fb5dfa00b0xffffff80c9a3b550 : 0xffffff7f9dc66f3f0xffffff80c9a3b5b0 : 0xffffff7f9dc30d310xffffff80c9a3b5e0 : 0xffffff7f9dc434ac0xffffff80c9a3b630 : 0xffffff7f9dc437e50xffffff80c9a3b6d0 : 0xffffff7fb5ded3680xffffff80c9a3b710 : 0xffffff7fb5ded7190xffffff80c9a3b9b0 : 0xffffff7f9dc342520xffffff80c9a3b9e0 : 0xffffff7fb5dee8f10xffffff80c9a3ba70 : 0xffffff7fb5dec94b0xffffff80c9a3bad0 : 0xffffff7fb5dec7410xffffff80c9a3bb20 : 0xffffff7fb5deb81d0xffffff80c9a3bb60 : 0xffffff801d683a8c0xffffff80c9a3bcc0 : 0xffffff801cf872e60xffffff80c9a3bdd0 : 0xffffff801ce5c9ab0xffffff80c9a3be60 : 0xffffff801ce731f90xffffff80c9a3bef0 : 0xffffff801cfb35aa0xffffff80c9a3bfa0 : 0xffffff801ce22256Kernel Extensions in backtrace:com.apple.iokit.IOAcceleratorFamily2(462.8)[F0D1B5AF-356A-3F86-8829-8F00218602CB]@0xffffff7fb5da6000->0xffffff7fb5e10fffdependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[2B96E04B-E2A5-3296-AF14-6A766880A652]@0xffffff801e5a1000->0xffffff801e5c2fffdependency: com.apple.iokit.IOGraphicsFamily(597)[BBEE13AB-2291-37D9-AAE4-9E565E8950A5]@0xffffff7fb5f3f000->0xffffff7fb5f6dfffdependency: com.apple.iokit.IOPCIFamily(2.9)[654ABF9D-EB24-3B64-AB1C-EC2AC8357192]@0xffffff801fa24000->0xffffff801fa4ffffdependency: com.apple.iokit.IOReportFamily(47)[5578189C-7C1D-3158-B357-F8D6A216DCE1]@0xffffff801fa61000->0xffffff801fa63fffdependency: com.apple.iokit.IOSurface(302.14)[F0BF8EFA-AA35-37B5-B3AB-A8BCF5E62024]@0xffffff801fb94000->0xffffff801fbb0fffcom.apple.kext.AMDRadeonX4000(4.0.8)[B7BDCB57-0EF9-37E9-B724-29D96491A4FB]@0xffffff7f9dc2b000->0xffffff7f9e07dfffdependency: com.apple.iokit.IOAcceleratorFamily2(462.8)[F0D1B5AF-356A-3F86-8829-8F00218602CB]@0xffffff7fb5da6000->0xffffff7fb5e10fffdependency: com.apple.iokit.IOGraphicsFamily(597)[BBEE13AB-2291-37D9-AAE4-9E565E8950A5]@0xffffff7fb5f3f000->0xffffff7fb5f6dfffdependency: com.apple.iokit.IOPCIFamily(2.9)[654ABF9D-EB24-3B64-AB1C-EC2AC8357192]@0xffffff801fa24000->0xffffff801fa4ffffdependency: com.apple.iokit.IOSurface(302.14)[F0BF8EFA-AA35-37B5-B3AB-A8BCF5E62024]@0xffffff801fb94000->0xffffff801fbb0fffProcess name corresponding to current thread (0xffffffae57bf2000): com.apple.WebKit.WebContentMac OS version:21F79Kernel version:Darwin Kernel Version 21.5.0: Tue Apr 26 21:08:22 PDT 2022; root:xnu-8020.121.3~4/RELEASE_X86_64Kernel UUID: 3C587984-4004-3C76-8ADF-997822977184KernelCache slide: 0x000000001cc00000KernelCache base: 0xffffff801ce00000Kernel slide: 0x000000001cc10000Kernel text base: 0xffffff801ce10000__HIB text base: 0xffffff801cd00000System model name: iMac18,3 (Mac-BE088AF8C5EB4FA2)System shutdown begun: NOPanic diags file available: YES (0x0)Hibernation exit count: 0System uptime in nanoseconds: 340686258085148Last Sleep: absolute base_tsc base_nanoUptime : 0x000135da33649f64Sleep : 0x0000000000000000 0x0000000000000000 0x0000000000000000Wake : 0x0000000000000000 0x000000107080ddae 0x0000000000000000Compressor Info: 5% of compressed pages limit (OK) and 18% of segments limit (OK) with 16 swapfiles and OK swap spaceZone info:Zone map: 0xffffff99901f0000 - 0xffffffb9901f0000. PGZ : 0xffffff99901f0000 - 0xffffff99951f1000. VM : 0xffffff99951f1000 - 0xffffff9e612bd000. RO : 0xffffff9e612bd000 - 0xffffff9ffa856000. GEN0 : 0xffffff9ffa856000 - 0xffffffa4c6922000. GEN1 : 0xffffffa4c6922000 - 0xffffffa9929ef000. GEN2 : 0xffffffa9929ef000 - 0xffffffae5eabc000. GEN3 : 0xffffffae5eabc000 - 0xffffffb32ab89000. 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Worked just as advertised ...

Great price on a great product. iMac recognized the modules and everything works wonderfully. Highly recommended.