DTP in Serial, not in Parallel

I've a big issue of performance and internal memory with a DTP load because in the transformation there's a complex end routine.  Now I'm facing a problem of internal memory while launching the DTP, this ends always in status red.  Now DTP is defined as "Serial Extraction, Immediate Parallel Processing".
I've checked this post: https://scn.sap.com/thread/2077132 and I cannot see other options for my DTP (from an InfoCube to an DSO), just that one, and the thing is that I think if DTP is launched as serial extraction and not in parallel my memory issue would be solved (not sure anyway). 

The help I need is how I can change the mode DTP works, because I just see two options, the one is defined right now: "Serial Extraction, Immediate Parallel Processing" and "debugging" one.

Sol:

It looks like you just want to set it to 1 parallel processes at a time, which is essentially serial loading.

You can change the number of processes in the Settings for Parallel Processing in the DTP. I believe the default (depending on your system) is 3. You can change the Number of Processes to 1, and should achieve your desired result.

Sol:

Have you defined Semantic Groups in the extraction tab of DTP? Please increase no. of parallel proceses in DTPsettings.

You cannot define the processing type in the Execute tab. The system gives you the option by based on source and target.
Go to DTP-->Go to all context menu items-->Batch settings will be there. go thee and add 5 and save it and execute the dtp

Processing mode is defined by the system based on your source.
Try the below option
From the DTP batch manager increase the no of parallel process and execute the DTP and check.