Prof. Dr. Tilmann Rabl


We are happy to announce that our 2020 SIGMOD paper with the title 'Pump Up the Volume: Processing Large Data on GPUs with Fast Interconnects' received a reproducibility badge award.

Find the link to the ACM library here: https://dl.acm.org/doi/10.1145/3318464.3389705

Abstract: GPUs have long been discussed as accelerators for database query processing because of their high processing power and memory bandwidth. However, two main challenges limit the utility of GPUs for large-scale data processing: (1) the on-board memory capacity is too small to store large data sets, yet (2) the interconnect bandwidth to CPU main-memory is insufficient for ad hoc data transfers. As a result, GPU-based systems and algorithms run into a transfer bottleneck and do not scale to large data sets. In practice, CPUs process large-scale data faster than GPUs with current technology.
In this paper, we investigate how a fast interconnect can resolve these scalability limitations using the example of NVLink 2.0. NVLink 2.0 is a new interconnect technology that links dedicated GPUs to a CPU. The high bandwidth of NVLink 2.0 enables us to overcome the transfer bottleneck and to efficiently process large data sets stored in main-mem-ory on GPUs. We perform an in-depth analysis of NVLink 2.0 and show how we can scale a no-partitioning hash join be-yond the limits of GPU memory. Our evaluation shows speed-ups of up to 18× over PCI-e 3.0 and up to 7.3× over an op-timized CPU implementation. Fast GPU interconnects thus enable GPUs to efficiently accelerate query processing.