Slow cube build in batch

[terry_stjean]

We have upgrade our Transformer models from 7.4 to 10.2
We are running the 10.2 cube builds on new Windows 2008 servers with the same CPU's, memory, disk space as our 7.4 servers.
The Data warehouse for 10.2 is a new SQL Server 2008 R2 instance while the 7.4 uses SQL Server 2005.
Looking at the log files, I can see the data reads are faster on the 10.2 cognos.
All of the cube builds on 10.2 take the same time or run slightly faster than the 7.4 builds except for 1.
This one model, when run from our scheduling software or the Windows Task scheduler,  takes about 30 minutes on our 7.4 server but takes about 3 1/2 hrs on the new 10.2 server.
If I run the 10.2 cube build interactively, then it takes about 30 minutes.
When it's run from the scheduler, it starts with a priority of Below Normal but changing it to normal has not impact.
Any suggestions what else I can look at?