Hello all, I'm buying some memory for my new iMac but I'm not getting it from Apple. As I'm in the UK, I'm going for memory from Crucial (if you know of anyone better, please let me know). Anyway, there are two options, one is slightly more expensive but I was just wondering what the difference was and which one to go for. I don't really care about the price difference, just what the benefit may be. Option 1: DDR2 PC2-4200 CL=4 UNBUFFERED NON-ECC DDR2-533 1.8V 128Meg x 64 £82.24 inc. VAT Option 2: DDR2 PC2-5300 CL=5 UNBUFFERED NON-ECC DDR2-667 1.8V 128Meg x 64 £86.94 inc. VAT Thanks if you can help explain it!