3DMark is a computer benchmarking tool created and developed to determine the performance of a computer's 3D graphic rendering and CPU workload processing capabilities.
UL has released the free versions of its legacy benchmarks along with official serial numbers which can be used to validate your results online. Here they are:
3DMark99: 78TR2-8DBDU-BMXXS, user: Futuremark
|1999 (3DMark99)||Legacy 3DMark benchmarks