New Veeam Speed Record?

[vmbackupuser]

Firstly this is definitely not a complaint but just a curiosity

On avg our Veeam backup jobs speeds are between 70MB/s to 600MB/s in SAN Mode.
These VMs are 80 - 100GB in size, and all run on VMFS Luns formatted with 1MB block size.
Recently we created new VMs on new vmfs 4MB block size LUNs, as these new VMs each require 2 x 1TB vdisks.
Although at the moment most of the space in the 1TB vdisks are unused, we were pleasantly surprised by the backup time of 5mins, and a processing rate of 8GB/s !!!!
A new SAN Mode speed record? Or perhaps an anomaly in the calculation of the processing rate?
Any idea why the smaller VMs on 1MB block size LUNs don't achieve close to those speeds?

BTW, our config is as follows:
1 x physical VeeamBackup server (HP BL460c Blade)
HP BL465c Blade vSphere 4.0 Hosts
HP EVA 8100 Storage Arrays.
All 4GB SAN Switches & HBAs.

[Gostev]

Processing rate is pretty meaningless with CBT, this is the legacy counter coming from VCB-based backup which did not have changed block tracking, so whole VM image was needed to be read each time to determine the changed blocks. In fact, we are removing this counter in the next release.

Basically, (Processing rate) = (VM size) divided by (total VM processing time). This should explain why larger numbers can be achieved on larger VMs. If you get 2 VMs with no disk changes since last run, one VM is 1TB and another VM is 100GB, then under the same circumstances first VM will be processed with 10x faster processing rate.

Thanks.