In order to get accurate performance predictions, design-time architectural analysis of multicore embedded systems has to consider communication overhead. When communicating tasks execute on the same core, the communication typically happens through the local cache. On the other hand, when they run on separate cores, the communication has to go through the shared memory. As the shared memory has a significantly larger latency than the local cache, we expect a significant difference between intra-core and inter-core task communication. In this paper, we present a series of experiments we ran to identify the size of this difference, and discuss its impact on architectural analysis of multicore embedded systems. In particular, we show that the impact of the difference is much lower than anticipated.