Aspire 3 315-34 Why is full 8GB ram not recognized?

nuclearrepairman

I have an Acer Aspire 3 315-34.  I installed a 8GB DDR4-2400 SODIMM #CT8G4SFS824A and my laptop recognizes all 8GB for 12GB total.  When I install a 8GB DDR4-3200 SODIMM # CT8G4SFRA32A it only recognizes 4GB of the 8GB/ 8GB total.  Why is this and is there any way to get it to recognize all 8GB of the 3200 SODIMM? 

{Thread was edited to add model name to the title}

JackE

Sorry. While 3200MHz sodimms should in theory downshift to 2400MHz to accomodate the buss, in practice they often don't.You should return the crucial 3200MHz for a refund and purchase another brand of 2400MHz or 2666MHz if need be.

JackE

It's often best to try to match the 2400MHz onboard 4GB DDR4 RAM. Since your buss only allows 2400MHz maximum RAM speed, a 2400MHz 8GB DDR4 sodimm is perfect. A 3200MHz sodimm would not increase the 2400MHz buss speed even if all 8GB were recognized.

nuclearrepairman

Thanks for your reply.  I bought the 3200MHz for my daughter's identical laptop because the supplier was out of 2400MHz.  Crucial's scanner hardware said the 3200MHz was also compatible with my laptop.

padgett

It should be compatible IF both RAM chips are identical. Mixing two different speeds can be an issue. Does the 3200 alone work ? If so might need to buy another one the same.

nuclearrepairman

My laptop has 4GB permanent onboard.  It has 1 memory slot.  When I put in the 8GB 2400Mhz SODIMM it shows 12Gb.  When I install the 8GB 2400MHz SODIMM it shows 12GB.

JackE

Sorry. While 3200MHz sodimms should in theory downshift to 2400MHz to accomodate the buss, in practice they often don't.You should return the crucial 3200MHz for a refund and purchase another brand of 2400MHz or 2666MHz if need be.

nuclearrepairman

Thanks for the help.  Return it is.