iMac Memory Upgrade question

[BeedaLou]

Just bought a new 27 inch imac retina. I want to upgrade the memory. Specs say to use 1867mhz, but 1866mhz is cheaper. Can I use 1866? If so, will it work alongside the 1867mhz that's already there?

 

[marzfreerider]

You can buy that 1866 RAM, I bought this RAM from Kingston and it said 1866. On the about this Mac its says 1867.
I've been using it for 3 months with no problems.

The specs are:

CAS Latency CL11
Number of Modules 2 x 8 GB
Signal Processing Unbuffered
Form Factor SoDIMM
Length 2.7"
Memory Speed 1866 MHz
Memory Size 16 GB
Memory Technology DDR3L SDRAM
Width 1.2"
Memory Voltage 1.35 V
ProductId 1029992813

General Information
Brand Name: Kingston
Manufacturer: Kingston Technology Company
Manufacturer Part Number: HX318LS11IBK2/16
Manufacturer Website Address: http://www.kingston.com
Product Line: HyperX Impact
Product Name: Impact SODIMM - 16GB Kit* (2x8GB) - DDR3L 1866MHz CL11 SODIMM
Product Type: RAM Module
Physical Characteristics
Form Factor: SoDIMM
Length: 2.7" (67.6 mm)
Width: 1.2" (30 mm)
Technical Information
CAS Latency: CL11
Memory Size: 16 GB
Memory Speed: 1866 MHz
Memory Technology: DDR3L SDRAM
Memory Voltage: 1.35 V
Number of Modules: 2 x 8 GB
Signal Processing: Unbuffered