Any small disappointment: the Windows Experience Index of recall is unchanged (7.4) because my old memories hynix were already of excellent quality.
This doubling of memory had become necessary because I use a parallel Windows 7 (32 bit) under VirtualBox virtual Oracle.
I also tested the new Windows 8 (preview) under VirtualBox.
In conclusion: quality memory modules, what is expected from Samsung, at a reasonable price today.