The IP reuse approach and FPGA-platform-based SoC (System on Chip) with an embedded soft processor is an alternative to design SoCs that allows fast creation and verification. In this paper we address a comparison study between two SoCs architectures based OpenRISC (OpenCores) and MicroBlaze (proprietary) soft processors. The comparison is done for two applications, namely the audio and network applications based SoCs. The SoCs have been prototyped using the Virtex5 XC5VLX50 FPGA. Regarding the SoCs for audio application, the results show that slices are more used in the OpenRISC based SoC while BRAM memories are more used in the SoC based MicroBlaze. Concerning the SoCs for Network application used slices register are slightly different in the two SoCs, BRAM memories and slice LUTs are more used in the OpenRISC based SoC. We notice that power consumption is better for the SoCs based MicroBlaze for the both applications.