Hey Guys, I have a Late 2011 13'' Macbook Pro, which is running dead slow. I want to buy a 4gb ram so I can add it to the original one and have 8gbs. Since I am budget constrained, I was looking for the most accessible ram chio, and came across the following 4. I would like to know if these are compatible with the Macbook before everything, and if you have any suggestions on which. http://www.amazon.co.uk/Corsair-CMS...2&sr=1-44&keywords=ddr3+pc3+10600+1333mhz+4gb http://www.amazon.co.uk/PC10600-133...79&sr=1-2&keywords=ddr3+pc3+10600+1333mhz+4gb http://www.amazon.co.uk/Crucial-CT5...ON-ECC/dp/B005LDLV6S/ref=cm_cr_pr_product_top http://www.amazon.co.uk/Corsair-CMS...9&sr=1-11&keywords=ddr3+pc3+10600+1333mhz+4gb Thanks guys!