My motherboard is a G1.Sniper 5 on the Z87 chipset, this is basically what it can take on the spec below, my OS is Windows 10 64 bit, my GPU is a Sapphire Vapor X 290X 8GB 4 x DDR3 DIMM sockets supporting up to 32 GB of system memory * Due to a Windows 32-bit operating system limitation, when more than 4 GB of physical memory is installed, the actual memory size displayed will be less than the size of the physical memory installed. Dual channel memory architecture Support for DDR3 3000(O.C.) / 2933(O.C.) / 2800(O.C.) / 2666(O.C.) / 2600(O.C.) / 2500(O.C.) / 2400(O.C.) / 2200(O.C.) / 2133(O.C.) / 2000(O.C.) / 1866(O.C.) / 1800(O.C.) / 1600 / 1333 MHz memory modules Support for non-ECC memory modules Support for Extreme Memory Profile (XMP) memory module A couple of questions 1. Memory wise i'm currently running 2 x 4GB 2133 MHz modules which are Avexir with the green flashing lights, it seems Overclockers no longer stock them, any ideas as to why ? 2. What's the optimum speed i should get as an upgrade, i think i read somewhere that you shouldn't go above 2600MHz or there abouts as windows won't recognise it. 3. Is it better to fill all the memory slots. as an example would 4 x 4GB be better than using 2 x 8GB ? 4. If i can't get Avexir again, what brands would you suggest as i've lost touch with what's good and what's not good these days. Why has the price on memory gone through the roof ?