We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Green circuit board with black memory chips and gold edge connector

Crucial

Crucial CT16G4S266M 16GB DDR4 2666 SO-DIMM memory upgrade

SKU CH-J14G-5H8NQ MPN CT16G4S266M

16 GB DDR4 SO-DIMM tested for the 2019 27-inch iMac Retina 5K at 2666 MHz

  • Total capacity16 GB
  • Rated speedDDR4 2666 (PC4 21300)
  • CAS latency19
  • Rated voltage1.2 V
  • Buffer typeUnbuffered
  • Product type260-Pin DDR4 SO-DIMM
  • Boosts iMac responsiveness with 16 GB DDR4 2666 memory
  • Low 1.2 V operation reduces system power draw
  • CAS latency 19 delivers snappy data access
  • Validated for 27-inch 2019 iMac Retina 5K models
  • Rigorous component-level testing ensures reliable operation

16 GB DDR4 SO-DIMM for 2019 iMac

This 16 GB DDR4 2666 SO-DIMM is built for the Apple iMac Retina 5K, 27-inch, 2019 models with 3.0 GHz or 3.4 GHz Intel Core i5 processors. The 260-pin unbuffered module runs at 1.2 V with CAS latency 19. Every unit is tested at component and module level before shipping.

Suits owners of the specified 2019 iMac

It fits the iMac 19,1 platform and installs without special tools. Builders working on Windows laptops, earlier Macs, or any system that requires ECC or registered memory should look elsewhere. The module is non-ECC and unbuffered, so it will not meet server or workstation requirements.

260-pin DDR4 2666 SO-DIMM form factor

The 260-pin DDR4 SO-DIMM interface is the single specification that decides compatibility. Only systems designed for this exact pin count, voltage, and speed will accept the module. Verify your model matches the 2019 27-inch iMac before purchase.

How it compares

Measured against everything we stock in Model-Specific Memory Upgrades, at today’s prices. Recalculated every night.

Price $25.99
Cheaper than about 87% of the 21,161 comparable items (median $397.99).
Total capacity 16 GB
Lower than about 70% of the 20,941 comparable items (median 32 GB).
CAS latency 19
Lower than about 70% of the 483 comparable items (median 22).
Price per GB $1.62 per GB
Cheaper than about 95% of the 20,941 comparable items (median $8.19 per GB).

New to this? Buying memory and SSDs with crypto — what to check, what it costs to pay, and what is never asked for.

Specifications

Product
Brand nameCrucial
Model nameCT16G4S266M
Total capacity16 GB
Product type260-Pin DDR4 SO-DIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Memory
CAS latency19
ECC supportNo
Buffer typeUnbuffered
Power
Rated voltage1.2 V
Size & build
Shipping weight0.02 kg
Package size99 × 50 × 3 mm
Compatibility
Compatible withFor Apple iMac

Questions about this item

How much power does the 1.2V DDR4 module draw when the iMac runs all day?

The module operates at the standard DDR4 voltage of 1.2V, which keeps power draw low during continuous use.

Which slot type must my iMac have for this 260-pin SO-DIMM to fit?

Your iMac needs a DDR4 SO-DIMM slot accepting 260-pin modules; the 2019 27-inch Retina 5K iMac uses this format.

Will the CL19 2666MHz module run at its rated speed in my 2019 iMac with a 3.0 GHz Core i5?

Yes, the 2019 27-inch iMac with 3.0 GHz or 3.4 GHz Core i5 supports DDR4 2666, so the module runs at its full 2666 MT/s rating.

More in Model-Specific Memory Upgrades

Similar items