I have a 700 mb iges file and I need to open it to use it as a reference for another assembly thar I working on, but it seems that it's imposible to open it.
It may take some time, but it should open.
Two issues that may prevent it from working are:
1 - Errors in the iges file which cause it to fail.
2 - Lack of RAM which can cause SolidWorks to shutdown.
You could try to open in another program which is better accustomed to handling large files. Something like Design X may open it quicker and allow you to check it for errors before moving to SolidWorks.
I opened it in Catia V5R21 and everything was fine, it took a while but the model had no errors. I converted the file from iges to cgr and the size went from 700 mb to 60 mb, the problem now is that I can't move the model at all.
I tried to remove some unnecesary surfaces but since the model has a huge amount of parts it didn't make any difference the file was still too big.
I also tried to fuse all the parts into one single solid part but I just couldn't find the way to do it in Catia.
Prehaps my PC isn't strong enough for this files. I´ll try to open it in Desing X as you suggest, I hope it works.