If you experience slowness in drawings you have obtained by exporting from ideCAD, try the suggestions below.
Before merging the dwg drawings and working on them, explode the drawing and clean it with the "purge" command.
In general, hatches can cause slowness in drawing. Replace or scale up the hatch types you use in your drawings with less dense types.
Update the graphics card drivers.
If you are using a laptop, the onboard GPU is used instead of the graphics card GPU for battery efficiency. This can cause speed and crashing problems.
If your graphics card is NVIDIA, open the NVIDIA Control Panel dialog Manage 3D Settings tab. In the Global Settings section, select the "High-performance NVIDIA processor" option as the Preferred graphics processor.
Depending on the AutoCAD version you are using, check the settings related to this hardware use from a dialog similar to the dialog below.
From the System tab of the Options dialog, click the Graphics Performance button.
Hardware Acceleration can be enabled. This acts as an acceleration by using your graphics card as hardware. If it is off, viewing operations are performed without using the graphics card.
The 2D Display Settings setting includes image quality and speed options. Basic Mode can speed up your operations.
In addition, since Autocad equivalents such as ZWCAD and GstarCAD are slightly lighter software, they do not force computers and work faster. You can try demos of these softwares on low-configuration computers.