Are you using Lightroom or Lightroom Classic? Lightroom stores all of your photos in the cloud so you won't need the extra space unless you turn on the option to store a local synced copy. I can't really speak to the speed of the drive though.
if you are using Lightroom Classic, you are probably better off getting a larger external hard drive for your photos and just keep the catalog on the internal drive.
Didn't realise someone answered me! Thanks for your awnser 😀
I am using lightroom classic. I wanted my catalogue to be on a harddrive so I could use it on any computer (at work or at home). Still not entirely sure if 100mb/s, 500mb/s or 1000mb/s is best for lightroom. I'd assume faster was better but if it's only 5% faster or something, I'd rather save the money. I migjt go halfway and buy the 500mb/a drive.
Do you need to backup the catalog and previews that are on the internal drive or is keeping one copy on the internal drive sufficient? Also, what about the backups? Where should those be stored?
Guess what happens to your catalog if that external drive crashes... You should always make backups of your catalog, and those backups should be on a different drive. Either use Lightroom's built-in catalog backup, or use a general backup utility, but do it. Previews do not need to be backed up. Lightroom can rebuild them if needed.
The faster the drive, the faster Lightroom Classic will be. I can't give you any solid figures, but I think changing from 100 mb/sec to 500 mb/sec will give you a good speed increase, while going to 1000 mb/sec might not be that much faster anymore. It also depends on the speed of the USB ports in your computer.