Moving slightly away from topic, but the idea with building a computer is to minimize the bottleneck.
Most computers off the shelf have a huge bottleneck in their storage sub-system, be it Mac or PC. Compared to CPU, GPU and RAM, the storage is far behind, we are negating this by either using PCIe direct storage, or making arrays through RAID controllers.
Personally I am not looking at if mine is faster or slower then the next person's machine, but that what I do add to it, will improve the tasks I do. Unfortunately its not always so. I recently added another 48GB of ram to it, which resulted in that could not overclock it, so now I have to replace this and find another brand that will let me do so. In my particular case, I can use both ECC and NONE-ECC (EVGA SR-2), and it supports 1600Mhz ram.
There are some trade offs with every system, so far there isn't a perfect one - at least I haven't found it.
I started this system back in the end of 2010, and expecting it to work till 2015, with modifications done to it as we go along.
i do alot of pano's some of them in 10's of gigabytes, but also work with multi-layered files all the time( As i am sure most of us do ;-) ), to me the biggest bottleneck is actually Photoshop inability to use multicores to save with, CS6 has helped a bit, that it can save in the background, but still its not that fast - as in I want it to be faster ;-)
with your newer systems, you can only add so much ram, before you start seeing that your clock rates starts to drop, but also you will not be able to take full advantage off it when it comes to deliver the data to the disk, it will simply just cue up.
PS: Please share you system config
EVGA SR-2 mainboard
2x Intel X5650 @ 4.3Ghz
48GB 1333 RAM ECC (soon to be 96GB again)
12x Intel SSD 520
8x Seagate SV-35 2TB 7200rpm
2x IBM M1015 RAID HBA controller - to be replaced with Areca 1882xi 24 4GB cache + BBU
Antec 1200w PSU
Lian Li v2120 black case
Noctua 14 heatsinks and fans in the system, almost silent ;-)