[Apache]

I am trying to crack some hashes i got recently. I considered using services like vast.ai, AWS, DigitalOcean, Linode, and others.
Has anyone already used these services?

[notagh0st]

Are the hashes salted at all? If they aren't, the first place I would check is a leaked database, find someone with the same hash that has already been decrypted as part of a leak. Something like snusbase. Look the hash up, see if anyone else is using that password, and then check to see if any of those have been cracked. The second option I would go with would be rainbow tables. The third option would be a dedicated server with multiple CPU's, and a decent amount of RAM, then running John The Ripper on it with multiple processes running at once.

If the hashes are salted, and you don't have the salt, that's going to be a problem, and increases the difficulty exponentially.

[Apache]

Are the hashes salted at all? If they aren't, the first place I would check is a leaked database, find someone with the same hash that has already been decrypted as part of a leak. Something like snusbase. Look the hash up, see if anyone else is using that password, and then check to see if any of those have been cracked. The second option I would go with would be rainbow tables. The third option would be a dedicated server with multiple CPU's, and a decent amount of RAM, then running John The Ripper on it with multiple processes running at once. 

If the hashes are salted, and you don't have the salt, that's going to be a problem, and increases the difficulty exponentially.

The hashes are not salted. Thank you for the tips

[Sneed]

I have not used vast.ai myself but I know people in HashMob use them, so they must be pretty good.