Manycores are very effective in scaling parallel computational performance. However, it is not clear if current memory technologies can scale to support such highly parallel processors. In this paper, we examine the memory bandwidth and footprint required by a number of high-performance scientific applications. We find such applications require a per-core memory bandwidth of 300MB/s, and have a memory footprint of some 300MB per-core. When comparing these requirements with the limitations of state-of-theart DRAM technology, we project that in the scientific domain, current memory technologies will likely scale well to support more than 100 cores on a single chip, but may become a performance bottleneck for manycores consisting of more than 200 cores.