This paper analyzes the rate-distortion-complexity of HEVC reference video codec (HM) and compares the results with AVC reference codec (JM). The examined software codecs are HM 6.0 using Main Profile (MP) and JM 18.0 using High Profile (HiP). These codes are benchmarked under the all-intra (AI), random access (RA), low-delay B (LB), and low-delay P (LP) coding configurations. In order to obtain a fair comparison, JM HiP anchor codec has been configured to conform to HM MP settings and coding configurations. The rate-distortion comparisons rely on objective quality assessments, i.e., bit rate differences for equal PSNR. The complexities of HM and JM have been profiled at the cycle level with Intel VTune on Intel Core 2 Duo processor. The coding efficiency of HEVC is drastically better than that of AVC. According to our experiments, the average bit rate decrements of HM MP over JM HiP are 23%, 35%, 40%, and 35% under the AI, RA, LB, and LP configurations, respectively. However, HM achieves its coding gain with a realistic overhead in complexity. Our profiling results show that the average software complexity ratios of HM MP and JM HiP encoders are 3.2× in the AI case, 1.2× in the RA case, 1.5× in the LB case, and 1.3× in the LP case. The respective ratios with HM MP and JM HiP decoders are 2.0×, 1.6×, 1.5×, and 1.4×. This work also reveals the bottlenecks of HM codec and provides implementation guidelines for future real-time HEVC codecs.