Hi @Geeku!
Are you looking for a portable or desktop external drive?
For a portable external drive I can recommend WD Elements and WD My Passport Ultra. They both are very good and reliable drives, and the only difference between them is that the second one is hardware encrypted and password protected while the first one is not. As for the maximum capacity, WD Elements comes with maximum available storage space of 2TB while WD My Passport is up to 4TB. Here's a link you if want to take a look:
WD Elements - http://products.wdc.com/support/kb.ashx?id=dhOJDN
WD My Passport Ultra - http://products.wdc.com/support/kb.ashx?id=astczY
On the other hand, in case you're after a desktop external drives you can take a look at WD My Book which is also hardware encrypted and password protected and comes with capacity up to 8TB. You can check it out here:
WD My Book - http://products.wdc.com/support/kb.ashx?id=vPhck5
Hope this helps and feel free to ask any questions you may have.
I'm at a latency of 10 and overclocked to 2200MHz with my RAM. That gives you an improvement but only is specific tasks. The 1.1GHz overclock on my CPU has given me improved perceivable performance gains on just about everything I do. Overclocking the RAM can impact your ability to overclock you CPU, so my advice is overclock the CPU first.