Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
fio - Generate I/O for benchmarking, stress testing, verification or workload reproduction purposes.
HWiNFO - Professional System Information and Diagnostics. Comprehensive Hardware Analysis, Monitoring and Reporting for Windows and DOS. FREEWARE. download. Advertisements.
CrystalMark - CrystalMark is a full included benchmark application that can be utilized for surveying the execution and capacities of a PC.
SpeedFan - Hardware monitor for Windows that can access digital temperature sensors located on several 2-wire SMBus Serial Bus. Can access voltages and fan speeds and control fan speeds. Includes technical articles and docs.
Iometer - As the Iometer Users Guide says, Iometer is an I/O subsystem measurement and characterization tool...