Reliable and fast memory for Gigabyte's x48-DX6

[bramdo]

Hello,

i had to buy a new mainboard on one day notice so i've bought gigabyte's x48-DX6.
For the moment i have 2 times 2 gig og kingston's hyperx 6400.
What would you recommend as memory because the kingston will leave to a friends pc,
Thanks
Bram