Intelligent Data Centres Issue 12 | Page 22

INDUSTRY INTELLIGENCE POWERED BY THE DCA Data traffic has been growing at 60% CAGR for the past 15 years and the hardware capacity at 50% CAGR, such that data centre loads have grown at only 10% CAGR. at only 10% CAGR. There is now plenty of evidence that data traffic has flattened out in mature markets, including the UK, and data centre energy is stabilising for the moment – but that’s another story. The SPEC Power test regimes do not represent all loads (or any specific) but as a benchmark are very informative, although, as usual, ‘there are other test routines available’ etc. So how far and quickly have servers developed? For example, we can use SPEC to compare two servers that are both in service today but about six years apart in market release date. I will call them Server-A and Server-B, although you can make your own comparisons by looking at the SPEC listings for free. A good source of server performance data is the SPEC website where several hundred servers are listed by the OEMs, along with their performance against the SPEC Power software loading routines. that the lower limit for idle power in silicon chips would be 20%, but Server-B managed 13% (44W) in 2017. So, Server-B (not hugely different in purchase cost to Server-A) can, on power consumption alone, replace at least 270 modules of Server-A, a remarkable consolidation of 40 ICT cabinets into one. However, when Server-A was released, it was a very popular machine and offered huge performance compared to what went before it and at a lower cost. I remember seeing a HPC installation in the UK handling datasets for oil and gas exploration surveys using Server-A but I would assume that Server-A had a rated power consumption at 100% SPEC load of 394W and performed 26,880 operations per second – which resulted in 45 Operations/Watt. Its idle power (when doing no work at all) was 226W which is a surprising 57%, although that compared to some other servers of the time idled at a rather depressing 79%. Ian Bitterlin of Critical Facilities Consulting 22 Issue 12 In comparison, Server-B has a rated power consumption at 100% SPEC load of 329W (17% lower) and performs 4,009,213 operations per second (88,000x more) – which results in 12,212 Operations/Watt (270x more). Roughly five years ago, a whitepaper was written which predicted www.intelligentdatacentres.com