Installing System Components 69Installing the Cooling ShroudCAUTION: Many repairs may only be done by a certified service technician. Youshould only perform troubleshooting and simple repairs as authorized in yourproduct documentation, or as directed by the online or telephone service andsupport team. Damage due to servicing that is not authorized by Dell is not coveredby your warranty. Read and follow the safety instructions that came with theproduct.1 Position the cooling shroud by aligning the guide slots with the guidescrews on the system board. See Figure 3-11.2 Push the cooling shroud down until all edges are secured to the systemboard.3 Close the system. See "Opening and Closing the System" on page 50.System MemoryYour system supports single- and dual-rank DDR3 unbuffered ECC DIMMs(UDIMMs). DIMMs can be 1066 or 1333 MHz.The system contains four memory sockets. Each two-socket set is organizedinto two channels. The first socket of each channel is marked with whiterelease levers.General Memory Module Installation GuidelinesTo ensure optimal performance of your system, observe the following generalguidelines when configuring your system memory.NOTE: Memory configurations that fail to observe these guidelines can preventyour system from starting and producing any video output.• Except for memory channels that are unused, all populated memorychannels must have identical configurations.• Memory modules of different sizes can be mixed in sockets 1 to 4(for example, 2 GB and 4 GB), but all populated channels must haveidentical configurations.• Memory modules are installed in the numeric order of the socketsbeginning with 1 to 4.
