Capacitas: Performance and capacity planning consultancy and training services. Includes whitepapers. Head office located in London, UK.
Capacity Planning: White paper on the role of capacity planning in e-commerce, how to approach it, and how to maintain it.
Characterizing Web Response Time: Master's thesis by Binzhang Liu
CIMS Lab, Inc.: Software and services for resource accounting, capacity planning, and IT chargeback.
CMG - Computer Measurement Group: Professional organization for capacity planners.
DB2 System Performance Metrics: Here Joel Goldstein discusses various DB2 capacity metrics.
Jonathan Hardwick: Product information about Microsoft's System Center Capacity Planner.
Load Balancing Your Web Site: Practical Approaches for Distributing HTTP Traffic by Ralf S.Engelschall.
PerfCap Corporation: PerfCap Corporation provides Performance Management and Capacity Planning Products and Services.
PerfCap UK: Offers web-based cross-platform performance analysis and capacity planning tool. Also provides consulting services.
Performance Dynamics Company: Develops performance tools, evaluates performance-related products, designs system benchmarks, and troubleshoots performance problems. Contact information, events calendar, and links to software tools.
Red Hill Networks' WebSpray: This tool allows you to stress test your web server through a LAN or modem connection. It will generate reports for errors and performance.
Reg Day's Capacity Planning site: Cover mainframe capacity planning and various PC related subjects.
RRD TOOL: A useful open source tool for storage and retrieval of time series data.
Schema: Schema is a provider of telecom resource management (TRM) solutions that enable operators of wireless networks worldwide to optimize and manage their resources.
Transaction Design Inc.: Consultant and tools vendor with focus on system monitoring, capacity planning, and benchmarking. Tools work on HP/Compaq/Tandem NonStop Kernel, Stratus VOS, and UNIX. Site includes articles on management/performance topics for these OSs.
Watson & Walker, Inc.: Why Your CPU Capacity May Not Match Your Vendor's Estimate: Cheryl Watson discusses MVS and OS/390 capacity related issues.