Specs:

i5 2500K @ 4.1 GHz
Sabertooth P67 (BIOS revision 3602 [latest])
GTX 670 Power Edition SLI (Driver version 314.22)
8 GB DDR3 RAM @ 1600 MHz
1 TB SATA III HDD
Corsair GS800 PSU

Game settings:

1920 X 1080, Everything maxed out, V-sync on (in NVCP), SMAA 2X, Motion blur on low, Tessellation on

Autoexec:

Skip intro
FPS capped at 60
Chromatic Aberration set to off
Texture cache set to 512 MB

I notice that I get stuttering when playing the single-player, especially after the first time loading. If I spin around the game freezes for a good 3-5 secs before everything starts moving again, and even then it still stutters. This is especially apparent during the dam level. There's a checkpoint before you enter the area where the chopper drops off some CELL troopers (the area below the dam), and walking outside causes severe stuttering/FPS drops. I've tried stuff like messing around with FPS caps, limiting the maximum number of pre-rendered frames, using adaptive V-sync/no V-sync/etc. and running it in fullscreen-windowed mode, but nothing seems to help. I've managed to cross out the usual suspects like an unstable OC, overheating components, RAM issues, a fragmented HDD, viruses/malware and high DPC latency spikes, so I'm not really sure what to do. Any ideas?

Is that texture cache enough?
(don't know default value)

You have enough RAM try to disable swap file.It looks like the game is trying to load from the HDD a lot.

You have enough RAM try to disable swap file.It looks like the game is trying to load from the HDD a lot.

Would disabling the page file really help? I don't notice the HDD activity light blinking or remaining solid when the game freezes.

What I said try.You can also move it to another HDD.You can also try to disable the SLI and run the game with one card.The CPU might be a bottleneck too try to lower the settings for post processing.When you tried all of these we step into the gray area unfortunatelly but my bet is on the slow HDD.
I did assume you have 64bit windows to support that amount of memory in my previous post.