HP Dc5000 Hardware Reference Guide - HP Compaq Business Desktop dc5000 Microto - Page 16

Hardware Upgrades Memory Frequency 266 MHz 333 MHz 400 MHz Required Processor Bus Frequency 400 MHz, 533 MHz, or 800 MHz 533 MHz or 800 MHz 800 MHz If a memory frequency is paired with an unsupported processor bus frequency, the system will run at the highest supported memory speed. For example, if a 333 MHz DIMM is paired with a 400 MHz processor bus, the system will run at 266 MHz, the highest supported memory speed. ✎ The system will not start if you install unsupported DIMMs. DIMM Sockets The system will automatically operate in single channel mode or a higher-performing dual channel mode, depending on how the DIMMs are installed. ■ In single channel mode, the maximum operational speed is determined by the slowest DIMM in the system. For example, if the system is populated with a DIMM that is 266 MHz and a second DIMM that is 333 MHz, the system will run at the slower of the two speeds. ■ In dual channel mode, all DIMMs must be identically matched. DIMMs in the XMM1 and XMM3 black sockets must be identical; DIMMs in the XMM2 and XMM4 blue sockets must also be identical. Therefore, if you have one preinstalled DIMM in socket XMM1 and are adding a second DIMM, it is recommended that you install an identical DIMM into the XMM3 socket. If you are populating all four DIMM sockets, use identical DIMMs in each socket. Otherwise, the system will not operate in dual channel mode. 2-6 www.hp.com Hardware Reference Guide