Should read "fast enough for your camera" - an important detail you don't reveal. Beside this, your manual states the type of card required at minimum. Everything above is also possible but might not be utilized by the camera. If you use card readers for upload then a higher speed will shorten the upload time (provided your computer system can utilize the higher speed).
Assuming if thread starter continues to use Nikon D70s camera, as stated in user profile, for macro, event and landscape, a CF card at 133x times would suffice for mentioned situations.