While the international Galaxy S III model runs on a quad-core processor, the U.S. models utilize a 1.5GHz dual-core chip made by Qualcomm. They also have a whopping 2GB of RAM -- twice the RAM of their international brothers as well as all current high-end phones on the U.S. market.
So what's that actually mean? The phone is fast -- really fast. The Galaxy S III flies with most any task: Swiping between home screens is smooth, apps load instantly and Web browsing is as speedy as can be. No amount of multitasking seems to slow this sucker down.
That said, it's hard to quantify the effect of the extra RAM in real-world terms; even though the phone's speed is impressive, other recent high-end devices like the One X and Galaxy Nexus have similarly snappy performance. Based on my experiences, I'd say the Galaxy S III has a little extra zip in certain areas, but with the other top-tier phones being as fast as they are, it's tough to tell any major difference in most everyday usage.
The Galaxy S III uses a 2100 mAh battery that can be removed and replaced. I found the phone's battery life to be good but not incredible: One day, for example, I spent about an hour reading online content and a half-hour streaming music with Pandora. By lunchtime, my battery was down from a full charge to 58%; by 5 p.m., after a seven-minute phone call and a few minutes of quick on-and-off Internet usage, it was down to 36%.
Still, with moderate to heavy use, I was generally able to make it to the end of the day -- or close to it -- without getting a low-battery warning. The Galaxy S III is no Razr Maxx when it comes to stamina, but it's certainly no slouch.
The Galaxy S III comes with your choice of 16GB or 32GB of internal storage. It also supports up to 64GB of external storage via a microSD slot located beneath the back cover. Some models of the phone include 50GB of free Dropbox storage for two years; the AT&T and Verizon models, however, do not.
Samsung's Galaxy S III is 4G-ready, though connection type and speed will obviously depend on your carrier. The AT&T and Verizon models run on LTE right now, where such service is available, while the Sprint model will be limited to 3G data speeds until Sprint's LTE network has launched. The T-Mobile version, meanwhile, utilizes the carrier's HSPA+-level 4G network.