Last week we announced the general availability of two new instances called "compute intensive instances", A8 and A9, with 8 Cores/56Gb Ram and 16 Cores/112Gb Ram respectively. The maximum costs for the A8 and A9 instances are €1.83 and €3.65 per hour respectively.

These instances are currently only available within Cloud Services which means you can deploy your processing code to worker roles with auto scaling and achieve massive scale and performance. Compute-intensive instances are optimal for running compute and network-intensive applications such as high-performance cluster applications, applications using modelling, simulation and analysis, and video encoding. Each instance is connected via a 40 Gbit/s InfiniBand network that includes remote direct memory access (RDMA) technology for maximum efficiency of parallel Message Passing Interface (MPI) applications. 

These instances are not yet available on VMs where per minute billing applies.

For more info please see the link below

http://www.windowsazure.com/en-us/pricing/details/cloud-services/