HP Kayak XU 04xx HP Kayak XU Series 04xx, Familiarization guide - Page 27

Upgrading Main Memory Modules Upgrading Main Memory Modules The PC Workstation has 128 MB of unbuffered ECC SDRAM main memory installed in one DIMM slot. Can a 512 MB Registered memory module be added to a second DIMM slot to upgrade the memory? Error! RAM type No. To upgrade the memory, you can use 64 MB, 128 MB or 256 MB ubuffered memory modules (ECC SDRAM). Or, alternatively, replace the existing 128 MB memory module and install a 512 MB Registered ECC SDRAM memory module. Main memory modules are available in 64 MB, 128 MB, 256 MB and 512 MB ECC SDRAM modules. However, it is important to note that the 64MB, 128 MB and 256 MB modules are unbuffered ECC SDRAM modules, while the 512 MB modules are registered ECC SDRAM modules. Refer to the table on page 5 for details on how much main memory can be installed on each PC Workstation. Mixing Memory Modules Unbuffered and registered ECC modules are not compatible with each other, and cannot be mixed. If these have been mixed, this will be detected in the basic pre-boot tests when you boot the system for the first time. The BIOS checks that the inserted DIMMs are compatible with one another, and if it detects an error, it is reported to the HP MaxiLife. The error message (shown on the left) will then be displayed on the LCD status panel. Refer to the following table for DIMM compatibility rules. Original DIMM Type Unbuffered ECC Registered ECC (512 MB) Adding Unbuffered ECC Yes1 No Adding Registered ECC (512 MB) No Yes 27