Lucid Dreams

Say I have a domain XYZ.com, and I create subdomains:

keyword1.XYZ.com
keyword2.XYZ.com
keyword3.XYZ.com
etc..

Now none of them have dupe content, but are all on the same IP. Some may be on the same topic - but as I said there will be no dupe content.

Is there any major SEO penalty? (none of the sites will link to eachother)

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