I recently had a conversation with Mark Anzani, IBM’s CTO for System z, the mainframe platform. Regular readers will know that cooling technology is a favourite subject here on the hot aisle and I was keen to get an answer to how IBM plan to cool their next range of machines, the z11 series.
IBM have been using some quite innovative water cooling technology as part of their cool blue range of systems and I was keen to get clarification
“There are plans for water cooling on System z. Our next generation of server will have both water cooled and air cooled options and we have been discussing these future plans with our clients in briefings etc.”
IBM claim that direct water will be the cooling technology of the future. IBM say that removing excess heat from data centers is as much as 4000 times more efficient via water than it is by air. The water cooled technology was first introduced in the Power 575, a specialist HPC machine nicknamed the Hydro-Cluster.
The basic approach is to get cold water closer to the case or heat-sinks of the hottest components (generally the CPUs) the IBM technology uses cold plates physically bolted to the CPUs with centrally delivered chilled water channeled through them. This removes heat efficiently but is mainly targeted at getting the case temperature down so that the Power 6 chips can be over-clocked reliably delivering more performance for the same basic silicon.
I asked Mark if it was this same basic technology that was going to be used on the z11 and he confirmed the cold plate approach:
“Steve, yes -very much “back to the future” for us here in mainframe land”
I asked Mark when this next range with the water cooling option was due to ship.
“While we do not disclose exact timescales typically, the fact it will be available on our next generation, coupled with the fairly predictable cadence of our releases gives you a view to the timing.”
The z10 was first shipped into the market on the 26th February 2008 and the z9 on the 25th July 2005, a gap of some 30 months. On this basis we should see the z11 around September 2010.
As performance and density demands increase, water cooling becomes the obvious conclusion. It is nice to see the mainframe leading the way back to the future.