1st off.. how easy would it be to overload a computer running autocad with the videocard X1300?
What is that videocard worth and can it perform?
Is it normal to you guys that if a computer is running that videocard on a motherbord with a core2 duo chip(2.60 Ghz) that autocad becomes a pain to used once an item in autocad has been loaded with featured and options?
what are the performance differences between a 512mb radeon 4350HD and the X1300 ?
The X1300 is the entry level (ie low end) GPU from the 5xx family, introduced in 2005. It's a 4 pipe chip (4 pixels per clock) with 2 vertex engines IIRC, ie it should outperform comparable IGP parts but in turn would be outperformed by most other GPUs on the market. There were a few different models, differing in clock speed, memory speed and size - I imagine all of them would handle small Autocad models OK but would get sluggish with large models.
The HD4350 is essentially the same entry level model but from 2009 rather than 2005. It has quite a bit more shader power than the X1300 but in terms of pixel-pushing ability I wouldn't expect a big difference other than the higher clock rates of the newer cards.
You might be better off looking for a good deal on an HD4650 or 4670, which should be 2-4 times as powerful depending on workload.