Performance
We'd be surprised to see a modern-day, mid-tower chassis struggle with the demands of an overclocked Core i5-3570K processor. With dual exhausts and no active intakes, NZXT's S340 has no trouble keeping the CPU running cool under extreme load.
GPUs are more receptive to dedicated intakes, yet NZXT's chassis copes reasonably well with our dual Radeon HD 7950 graphics cards. Interestingly, the S340 delivers marginally better cooing results than the pricier H440, though do bear in mind the latter is kitted out with noise-deadening material.
It's the focus on silence that really sets the two chassis apart. The S340 isn't by any means loud, but its dual fans can be heard and if you want a build that's practically inaudible, the H440 remains the better bet.