From my side your computer may transfer from ex-Niroot, Your requirement point to high performance like pure engineering purpose, However the evident as you told me shown may came from fan and heat ventilation. Omya had contact with Local Dell in Vietnam also,
You can call their local phone number and as far as I know Dell had partner in Vinh City.
One more thing I saw quit strange cause Auto Cad 3D is dangerous to install, Can you provide me proof of purchase of this software, May be I forgot if I approve it, and if it's illigal you must take it off immediate;y before top management litigation from software owner. then process for approve before use it.
Hope you understand the standard process for our work.