Tower-style heatsinks are all well and good, but they can crowd the area around the CPU socket. That's bad news if you have tall memory modules with jumbo heat spreaders.
Thermaltake's newly announced NiC Series coolers purport to address that problem. The fin arrays on the NiC Series L31 and L32 are only 40-mm wide. Coupled with their bundled fans, they leave room for tall DIMMs on both sides of the processor socket, such as on Intel X79 platforms.
The NiC Series L31 is the smaller of the two. It's 140 mm tall and allows for up to 160W of thermal dissipation—still more than enough to handle Intel's hexa-core Core i7-4960X, which consumes up to 130W. The L31 also has three 8-mm heat pipes, and it comes with a 120-mm PWM fan that spins between 500 and 1800 RPM.
The NiC Series L32 is a little taller, at 160 mm, and comes with a larger, 140-mm PWM fan. Thermaltake quotes the same rotational speeds for both fans, so I'd expect the L32's 140-mm spinner to be a little quieter.