PC requirements and setup. Any advice appreciated.

[Neale]

Can't really comment on what AutoCAD needs - probably the most cpu-hungry piece of software you mention - but I would avoid laptops or similar compact machines if you are going to use them anywhere near your new machine. My first garage pc eventually started randomly shutting down in the middle of a job. Turned out to be the cpu heatsink full of dust causing overheating. Dust builds up everywhere inside. Laptops are much more sensitive to this and much more difficult to clean out. A decent-size desktop machine lets you take a panel off and stick a small vacuum cleaner nozzle inside. In a clean office environment, take your pick according to power needed/size/budget. Personally, I prefer to avoid laptops as you get more power/speed/reliability for the price from a desktop but if you need portability or small size, you have to compromise somewhere.

[cropwell]

You would be amazed at the capacity of a CNC machine to create a mess. If it is MDF based cutting then the fine dust gets EVERYWHERE. Metal is worse, as it is conductive and I have lost one motherboard this year from swarf ingress. Even with dust extraction some local filtration is a must. I would recommend one on your face to start with, then the PC should be in a case with filtered air being blown in. If you are running Mach3 and a parallel port, then a laptop is trouble because of timing issues and power saving.

I don't know about AutoCAD nowadays, but I run version R14, which is at least 20 years old, but does what I want. On a modern PC that can't be hogging too much in the way of resources.

[Lee Roberts]

If you get a small compact atom based system, say an Intel D525 (1M Cache, 1.80 GHz) based system, they don't really require additional cooling of the case they live in, filters on any intake fans/slots go along way still...

Coupled with proper machine isolation it should be a more or less non issue.

Link: Intel D525MW Intel Atom 1GB DDR3 RAM Mini ITX Bundle - £15.00