have a Lenovo G50-70 laptop (i5-4210U, 4 gigs ram, integrated graphics, 500 gig hdd) and I went to microcenter to buy another 4 gig stick of ram. The laptop can support 8 gigs, and has 2 slots, with one populated by a 4 gig stick. I knew that I could mix and mart ram as long as the timings were the same and if it was ddr3. So I bought a 4 gig stick of corsair ddr3 value select ram, ddr3. So I popped it in and the computer booted, and when I looked in taskmanager, it showed only 4 gigs of ram. I went into the bios, same thing. I updated my bios, still showing only 4 gigs. I booted with only the new stick in and it would not post...I checked online for both models of my ram (http://www.ramaxel.com/eng_Products.aspx?ClassIDPath=0%2c46%2c77%2c the old stick) and the new stick (http://www.amazon.com/Corsair-1600MHz-PC3-12800-204-Pin-CMSO4GX3M1C1600C11/dp/B00G40TB6E). I found that the old one was ddr3, and the new one ddr3L. When I looked up Lenovo G50-70 ddr3l, an article popped up about how the laptop only supports ddr3l. Well huh, becuase I have been using this laptop for a year now and have had no problems with the factory supplied ddr3 stick. Both sticks are CL 11, 1600 MHz, and ddr3l can supposedly up volt to 1.5 volts. So how can I use both sticks in my laptop? Thanks a bunch and let me know.