Solved Imac 5K 27 Ram Speed Discrepancy Imac Intel 27 Retina 5K Display

Chosen Solution

Hi, Yet again I’m confused – and I hope you can help me. I recently bought a 5K 27” iMac late-2015. I have just upped the RAM with 16GB of 1867 MHz 204-pin SODIMMs Apple specifies through their website. So now my total is 24GB of RAM. But upon installing it still says 1600 MHz in ‘about my mac’ – how can that be? Is it possible me make the iMac “think” it is a newer machine - I bought it via ebay, so I’m a bit afraid of the deal being a swindle. I’ve included a screenshot of Apples RAM recommendations and about my mac.   The system report of memory:   BANK 0/DIMM0:     Størrelse:                4 GB   Type:                       DDR3   Hastighed:              1600 MHz   Status:                    OK   Producent:              0x80AD   Produktnummer:    0x484D54343531533642465238412D52442020   Serienummer:         0x25581852   BANK 0/DIMM1:     Størrelse:                8 GB   Type:                       DDR3   Hastighed:              1600 MHz   Status:                    OK   Producent:              0x198   Produktnummer:    0x4B4858313836364331352F38472020202020   Serienummer:         0x35701602   BANK 1/DIMM0:     Størrelse:                4 GB   Type:                       DDR3   Hastighed:              1600 MHz   Status:                    OK   Producent:              0x80AD   Produktnummer:    0x484D54343531533642465238412D52442020   Serienummer:         0x25131812   BANK 1/DIMM1:     Størrelse:                8 GB   Type:                       DDR3   Hastighed:              1600 MHz   Status:                    OK   Producent:              0x198   Produktnummer:    0x4B4858313836364331352F38472020202020   Serienummer:                  0x35701602

Thank you! Rasmus EDIT: I’ve taken a picture of all the RAM modules. If it can help :)

Pull your 4 GB modules and then check again. I think what you are seeing is the slower modules are running at 1600 so your faster modules (1867 MHz) need to run at the slower clock.