"When it comes to buying cars," I explained to my friend, "it is actually quite similar to relationship choices we make. For example, I love BMWs. I rave about their attractive looks, desirable specifications, charming personality, and outstanding performance, but I would never buy one. It is like the girl you would not mind dating, but when it comes to marriage, it is wise to look elsewhere." Why is that? Well, for me, it will have to be the long term implications. Three or four years down the road, all the emotional factors I first had will soon be overshadowed by many practical considerations, like reliability and maintenance costs. Therefore, despite my frequent public profession of my admiration for BMWs, I always end up buying a Honda. Sure, emotional appeal is important. My Honda's looks, features, personality, and performance may not win over the BMW every time, but its well rounded package, in conjunction with affordability, low maintenance costs, great fuel economy, and top notch reliability will almost guarantee an excellent relationship for years to come. It is simply a choice that makes sense. As I have said in my SilverStone Strider Essential Gold 700W report last month, sometimes, practical considerations win over pure emotional desirability. In the storage world, it is no different. Obviously, you can slap several SSDs in RAID in your NAS with a 10GbE card and rip 500MB/s over your network, but how practical is that? If I am building a file server, what I want is a balance of speed, capacity, reliability, and affordability. When it comes to reliability, there is one brand that always pops up in the dictionary: Western Digital. And when it comes to speed, capacity, and affordability, the name for reliability has a color for you: Red. Designed specifically for network attached storage systems, the Western Digital Red WD40EFRX 4TB drives promises to excel in all four factors. Will it live up to all these promises? To find out, we took in not one, but four, to see how they perform in our synthetic and real life tests today. Read on to find out what we have found!