If you are talking about performance issues with dataloader CLI the below article might help https://developer.salesforce.com/forums?id=906F00000008ks5IAA
If you are using the dataloader GUI tool, it could most probably be with the system hardware.
I am talking about when I use the GUI. All I do is log on and tell it what object to load into and choose the file and then it hangs up on initializing. It works fine from the original computer I set this up on but I need others to load the data
I have experienced the same, but it was only when I was selecting a report output which had the footer report details. Try deleting those and try again.
https://developer.salesforce.com/forums?id=906F00000008ks5IAA
If you are using the dataloader GUI tool, it could most probably be with the system hardware.