IBM pledges to beat China's Sunway TaihuLight with 200-petaflop supercomputer

Promised for delivery in 2018, the Summit supercomputer will use IBM Power9 microprocessors

After China last week took top spot in the TOP500 rankings of the world's most powerful supercomputers, with the 93 petaflop Sunway TaihuLight, IBM has revealed more details about its forthcoming supercomputer that, it claims, will be capable of 200 petaflops.

The machine, called Summit, will be delivered to the US Department of Energy's Oak Ridge National Laboratory in early 2018. It should also be even more powerful than originally planned: when the project was announced in 2014, the aim was to deliver a machine running at around 150 petaflops.

The Summit and Sierra supercomputers had been announced in 2014 in a $325m deal between the US Department of Energy and IBM.

The first to be delivered, Summit, will use IBM Power9 microprocessors combined with Nvidia Volta graphics processing units (GPUs) providing maths co-processing.

The machine will deliver more than five times the computational performance of its predecessor Titan's 18,688 nodes using only around 3,400 nodes, claimed IBM. Each node will contain multiple IBM Power9 microprocessors and Nvidia Volta co-processors GPUs, all connected together with Nvidia's high-speed NVLink communications protocol.

Each node will have more than half a terabyte of coherent memory (high bandwidth DDR4 memory), plus 800GB of non-volatile RAM to serve as a burst-buffer or extended memory.

According to Oak Ridge, "to provide a high rate of I/O throughput, the nodes will be connected in a non-blocking fat-tree using a dual-rail Mellanox EDR InfiniBand interconnect".

The Titan supercomputer it replaces was based on AMD Opteron microprocessors, deployed Nvidia Kepler co-processors and had 32GB per node. While Sunway took top spot, Titan is no slouch and still occupies third place in the TOP500 rankings.

The Sunway TaihuLight claims a benchmark performance of 93 petaflops and a peak performance of as much as 124.5 petaflops. Most notably, however, it eschews US-designed parts for components designed and made in China. The ranking therefore raised more than a few eyebrows.

While Intel now dominates the market for supercomputer microprocessors - with a smattering of AMD and IBM Power microprocessors - the Sunway TaihuLight was powered by Sunway 260-core SW26010 microprocessors, combined with a custom proprietary interconnect.