Big Blue takes the fight to Xeons with Power7+ entry, midrange servers

Enter the slightly more portly Power 750+ and 760+ midrangers

The new Power 750+ machine comes in a 5U rack-mounted chassis, which is 1U taller than the Power 550 and Power 750 machines it replaces. Part of the reason is that this box has a lot more memory stuffed into it, which is enabled because by doubling up the processors per socket you also double up the memory controllers in the machine. This means you can double up the memory capacity, to a top of 1TB in this case.

Like its predecessors, the Power 750+ is a four-socket server, and in this case the sockets are stuffed with a Power7+ DCM with a total of eight cores running at either 3.5GHz or 4GHz. It would be cool if all 80MB of L3 cache memory on the Power7+ die was available to half the cores used in the DCM, but it looks like IBM is maintaining the same 10MB per core ratio in the DCM.

The good news is that you get two GX++ system ports coming off the pair of chips in the DCM, which allows you to hang as many as 1,302 drives off the machine for a maximum capacity of 1.17PB using 900GB disks. That is a lot of disk to be able to hang directly off a four-socket server with 32 cores.

The Power 750+ server has six PCI-Express 2.0 slots (presumably full height x8 slots) and has an integrated multifunction Ethernet card that gives customers a variant of different Gigabit and 10GE adapter options. The machine has only six drive bays, which looks to be a little skinny for a 5U box, but then again, this machine, like all other Power Systems boxes, assumes you will have remote I/O drawers and not try to have all the drives crammed into the server bay. (This is why you use InfiniBand as a storage interconnect, after all.)

The Power 760+ is essentially the same chassis but the DCM shifts from four cores running at 3.5GHz or 4GHz to six cores running at 3.1GHz or 3.4GHz. Why bother, you ask? Again, you have twice the memory controllers and twice the GX++ system buses coming out of those sockets, so giving up a little clock speed gets you a maximum of 48 cores in a four-socket machine, up to 2TB of main memory, and a little more than 20 per cent more aggregate throughput on jobs that like cores and threads than you can get with the Power 750+ system.

And, perhaps even more significantly, you have a box that overlaps nicely in terms of processing oomph with the low end of the Power 770+ system, giving customers who don't need as much peripheral expansion as the four-chassis, 16U Power 770+ system offers a machine that is more suited to their needs.

These two midrange Power7+ boxes offer the same operating system options as the baby Power7+ boxes. They will be available on March 15. ®