Hello khkris,  Thank you for your question! I see these values present in our Web Administration guide for OneFS 7.1+. In looking in to this the values are shown in bytes. These values are based on limitations of the NFS protocol and not necessarily OneFS (particularly this file size value). The performance metrics do line up from OneFS to the NFS limitations based on what I am seeing in the Guides.  For OneFS filesystem limits, I would look in to the Technical Specifications Guide (formally called the Guide for Large Workloads) that explains the test limits of OneFS. I will include a couple of links here, but they do require a login to support.emc.com:  7.1.1 Guidelines for Large Workloads 7.2 Technical Specifications Guide  Please let me know if there is anything else I can do for you.
While following the Isilon administration guide there are lot of values are mentioned with out metric like KB/MB/GB. For example the maximum file size is 9223372036854776000  and some other vaules for NFS performance.    Are these by default in KB ?  Thanks
Metrics on Isilon administration guide