Rapid visualization is essential for maximum intensity projection (MIP) rendering, since the acquisition of a perceptual depth can require frequent changes of a viewing direction. In this paper, we propose a CPU-based real-time MIP method that uses parallelization operations with the AVX instruction set. We improve shear-warp based MIP rendering by resolving the bottle-neck problems of the previous method of a matrix transposition. We propose a novel matrix transposition method using the AVX instruction set to minimize bottle-neck problems. Experimental results show that the speed of MIP rendering on general CPU is faster than 20 frame-per-second (fps) for a 512 × 512 × 552 volume dataset. Our matrix transposition method can be applied to other image processing algorithms for faster processing.