@azvarel normally there is a timeout function with retry... It try to download 3 times with 20 sec timeout for every file... And if it can't download, it will try the next rom... So it's strange you have a "crash"...
40 roms in 54minutes is very longue... (more than a minute by rom :S )
normally it's about 1 or 2 sec by roms... (even without multi-thread)
Wich rom are you trying to scrape ?
Exemple Big BIN or ISO files can take long time but it's not a "scrape" problem, it's an "Hash" problem...
Your computeur need to calculate a value based on the file you scrape...
If it's a big file and you have a pretty slow computer, it can take lot's of time...
For these "type" of file, You need to consider .CUE or .GDI files.
UXS will put you BIN in hidden without scrape them if you have a .CUE file with the same name