Actual consumption of GHz of a vCPU of a given VM is not provided in vCloud Director. You could do some portal on top of vCloud Director and provide it using something like vCenter Operations Manager, or other monitoring tools.
vCloud does allocation and consumption. For example the Allocation Pool is like saying I'll give you 20 GB of vRAM @ 50% guarantee. This means you can assign up to 40 GB of vRAM to VMs, and your 'consumption' happens at 50% of this rate. Same goes for vCPUs.