Hi Acmii,
We don't have a document that describes what you are looking for. Since Discover is mostly the same on both platforms, I would expect similar performance. However, on linux you must use JCIFS for scanning and it does not perform the same as the Windows native mounter. Also, it does not return File-Owner or Last-Access-Time for any file it scans. The biggest factor in a Discover Scan is the network and the time it takes to transfer the file from the target machine to the Discover server. DLP v12+ is 64bit only and does perform better than a 32bit server of the same type.
As far as windows vs linux goes, I would say it depends on your targets and desired outcomes. If you are scanning Windows shares and performing LDAP lookups based on the file-owner, then Windows is the way to go for Discover.
If you are scanning NFS or other share types, then Linux may be easier to configure. Also depending on your IT policies, one OS may have more overhead than another for support.
I hope this helps answer your questions. Please let me know if you have any more questions.
Best,
Ryan