Asus A53E K53E RAM replacement question

[broboa]

Hello everyone. I am having an Asus laptop. Model: A53E, Version: K53E.
So it is weird that my laptop has 2 slots for RAM memory and it uses 1 RAM of 2GB 1333Mhz and another is 4GB 1333Mhz.
http://www.amazon.co.uk/4GB-Memory-Asus-K53E-DDR3-10600/dp/B009787X92/ref=sr_1_1?ie=UTF8&qid=1414605544&sr=8-1&keywords=asus+a53e+ram

So is it okay if I will buy this RAM (1600 Mhz) and replace with it my 2gb RAM?
http://www.amazon.co.uk/Crucial-PC3-12800-SODIMM-Memory-Module/dp/B005LDLV6S/ref=sr_1_2?ie=UTF8&qid=1414605680&sr=8-2&keywords=ram+4gb+ddr3

Thank you very much for help in advance!

 

[WyomingKnott]

Yes, you can mix memory and the worst thing that happens is it runs as slow as the slowest stick (unless you a benchmarker, in which case you will see some small effects).

 

[sora]

Mixing RAM is fine, it will default to 1333MHz if one stick is 1333MHz and the other is 1866MHz though.