Are you getting green-weary? It would not surprise me if you were because everywhere one turns these days there is an another admonishment of the IT industry’s un-greenness or some announcement by yet one more company pitching itself at green sainthood. And when that company is IBM a little cynicism can be allowed, and when the system involved is the mainframe then a certain level of hilarity can readily be anticipated.   But the green argument is one of the strong suits being put forward by IBM in its promotion of the recently launched z/10 mainframe system, and numbers being quoted by the company are sufficient to make one stop giggling and take a bit of notice. They are, in short, very impressive, particularly if they really stack up over the long haul of a system lifecycle. 

The targets being quoted for the z/10 include an upto 80% reduction in energy consumption and costs, an 85% saving in floor space, which should prove attractive anywhere the price of property rates highly as a budget item, and an 80% reduction in associated datacentre labour costs through reduced support requirements. Those labour costs, of course, not only include direct salaries but all the attendant costs, not least of which is the energy consumed by their need for lighting, air conditioning and the rest. 

OK, so the important question here is what all these reductions are set against. If it was the previous z/9 mainframe that would be impressive but irrelevant to all but committed mainframe shops. In fact it is set against a datacentre of Linux servers. A single z/10 can run up to 4,000 virtual Linux servers which, using any other technology, equals a large number of racks. What is more, they can be run within the z/Series operating environment, which requires fewer sysadmin staff anyway, typically no more than a handful. The headcount for an x86 server datacentre is typically estimated at one sysadmin for every 10 servers, so 4,000 would require some 400 staff on that basis. 

Of course, the real question is whether those 4,000 virtual Linux servers can function as well as real x86 boxes. Only time and the evidence of users will prove that one way or the other. IBM claims that they can operate the same generalised workloads, and have them run with the higher levels of separation and security that are inherent parts of z/Series partitioning. As the z/10 now sports a new, 4.4 GHz processor, which will also be used at the heart of the IFL (Integrated Facility for Linux) processor specifically designed to process Linux code, it will be interesting to see how well it compares running a single-threaded Linux application that would normally run on an x86 server dedicated to its needs. 

But even if it does poorly, it will need to be very poor, or such an application will need to be particularly important to the business, for it to lose the overall economic argument – namely that IBM estimates it can cut the total operating costs of 3-4,000-server datacentres, compared against a handful of z/series machines running z/VM and Linux, over a five-year lifecycle, by more than half.  

That is one hell of an argument, I want users and vendors to argue it, but it is one you have to sit up and notice.