Hi, I would like to buy a small external ssd drive (128 gb) to boot up my base 2012 iMac computer. Would this 128 gb sized ssd drive work if I had the operating system as well as my documents/downloads installed in them? Also would this help extend the life of the internal hard drive (1 TB Seagate drive) inside my iMac? I basically use my computer for browsing the internet, writing documents, doing some research work, storing some photos, documents and downloads and occasionally looking at you tube videos. Thanks in advance for any assistance you can gave me with my inquiry!