Alfresco has published the results of their enterprise content management benchmark using MySQL 5.0 running on 64-bit Red Hat Enterprise Linux (RHEL). The benchmark uses a 10 million document repository across 10,000 folders and Alfresco was able to demonstrate linear scalability in a real-world scenario. The benchmark demonstrates online performance of batch load with mixed concurrent read and write operations under different user loads with different machine configurations. The benchmark was validated by Optaros, a consulting firm that specializes in open source project implementations.
Alfresco's design has been implemented in a modular, de-centralized fashion in order to enable highly efficient scale-out and the benchmarks showcase the efficiencies they have achieved. More details are available from Alfresco in their white paper.