DASH-IO: an empirical study of flash-based IO for HPC

HPC applications are becoming more and more data-intensive as a function of ever-growing simulation sizes and burgeoning data-acquisition. Unfortunately, the storage hierarchy of the existing HPC architecture has a 5-order-of-magnitude latency gap between main memory and spinning disks and cannot respond to the new data challenge well. Flash-based SSDs (Solid State Disks) are promising to fill the gap with their 2-order-of-magnitude lower latency. However, since all the existing hardware and software were designed without flash in mind, the question is how to integrate the new technology into existing architectures. DASH is a new Teragrid resource aggressively leveraging flash technology (and also distributed shared memory technology) to fill the latency gap. To explore the potentials and issues of integrating flash into today's HPC systems, we swept a large parameter space by fast and reliable measurements to investigate varying design options. We here provide some lessons we learned and also suggestions for future architecture design. Our results show that performance can be improved by 9x with appropriate existing technologies and probably further improved by future ones.