DPM Protection Groups, how many?

OK so I am trying to figure out what is the best way to create PGs in DPM 2012. From what the research I have done so far, one should create PGs depending upon the protection level and time.

So, for example of you have a 5 file servers whose data should be retained for 3 months and 10 database servers whose data should be also be retained for 3 months, you should create just one single PG.

Sure, you can also create two PGs, call one “file server PG” and the other “Databases PG” but I do not see any technical advantage of doing so.

So going forward, for example, if you have a bunch of dev servers who you wanna keep a backup of for only one month, sure go ahead and create a separate PG for them.

At one point I used to think that be creating 10 PGs, DPM will run 10 jobs simultaneously…. but that is not true. I have since found out that DPM has a limit of concurrent jobs  which is set to 3 by default. It is a registry setting which one can change.

I found this and some other, very good information here:

http://www.hyper-v.nu/archives/hvredevoort/2012/12/hyper-v-protection-with-data-protection-manager-2012-sp1/

By the way, I created a technet thread here about this topic.