My computer was slow to POST (about 1 or 2 minutes) and slowly booting (about a minute to minute and half even though I have the system on SSD), well it turned out to be my webcam, I removed the USB-plug and it started working again... But since the webcam is old and I tried removing my new USB headset already, I also tried to remove my RAM before disconnecting other USBs. So after gazillion CMOS resets, reboots and reattachments of the memories the computer now utilizes only half of it, even though they worked before. Both pairs (I have two 8 GB kits) work separately, but not together. In BIOS' "Asus SPD information" the mobo does recognize both pairs, but still BIOS, POST and Windows show I have 8 GB of RAM. Specs: Mobo: Asus P8H67 Memory: 2x4GB Kingston HyperX 1333MHz and 2x4 GB HyperX Savage 1600MHz CPU: Intel i5-3550 @ 3.3 GHz Running Windows 7 64-bit from SSD P.S. I have tried different combinations of sticks and slots. If I stick one of each, its 4 Gb, if I try with 3 sticks its 50-50 4 or 8 (I think the a-slots are first to come).