Our Summary and Conclusion
Clearly, the benchmark victor is the WD Caviar Black. There's a chunky caveat, however. The Caviar Black is $300 at Newegg, versus about $130 for the slightly smaller capacity Seagate Barracuda 1.5TB. Meanwhile, the WD RE4, which performed similarly to the Barracuda, goes for about $290.
With a cache twice as large as its competitor, the RE4 didn't exactly trounce the Barracuda. Interesting; in testing that doesn't exploit the larger cache, the two drives perform very similarly. Our standard desktop-type usage testing didn't exploit the larger cache pools but that's not to say in an enterprise-class environment, with a higher number of concurrent IO requests or perhaps even repeat larger file transfers, you might see a performance differential.
Furthermore, we installed games on each of these hard drives as you already know, and we also played them from each drive. In real-world action gaming, we truly didn't perceive a difference from one drive to the next. In fact, in virtually all forms of general computing, we couldn't differentiate which drive we were accessing; they all seemed the same. When access times differ in milliseconds, humans can hardly notice. Only our sensitive benchmark tests could tell the difference.
If you're looking for a very good drive with a large capacity at an excellent price, the Seagate Barracuda 1.5TB is a great choice. However, it's definitely not the speed queen of the bunch. For flat out performance and benchmarks that'll give you bragging rights to spill all over your buddies, save up your pennies and nab the Western Digital Caviar Black 2TB. It's a monster.
WD Caviar Black 2TB
WD RE4 2TB