Compaq W4000 Compaq Evo Workstation W4000 CMT Hardware Reference Guide - Page 25

Hardware Upgrades Installing Additional Memory Depending on your model, the computer comes with either synchronous dynamic random access memory (SDRAM) dual inline memory modules (DIMMs) or double data rate (DDR)-SDRAM DIMMs. The memory sockets on the Intel 845 chipset-based system board can be populated with industry-standard SDRAM or DDR-SDRAM DIMMs. These memory module slots are populated with at least one preinstalled memory module. To achieve the maximum memory support, you may be required to replace the preinstalled DIMM with a higher capacity DIMM. Ä CAUTION: Some models support ECC memory and some support non-ECC memory. For those systems that do support ECC, Compaq does not support mixing ECC and non-ECC memory. Doing so will cause the system to blink the NUMLOCK LED on the keyboard continuously and, if a speaker is installed in the system, there will be a short beep followed by two long beeps. In addition, the system will not boot the operating system. SDRAM DIMMs For proper system operation, if your system supports SDRAM DIMMs, the DIMMs must be industry-standard 168-pin, unbuffered PC133-compliant SDRAM DIMMs. The SDRAM DIMMs must support CAS Latency 2 or 3 (CL = 2 or CL = 3). They must also contain the mandatory Joint Electronic Device Engineering Council (JEDEC) Serial Presence Detect (SPD) information. DIMMs constructed with x4 SDRAM are not supported; the system will not start using unsupported DIMMs. Hardware Reference Guide 2-7