Compaq dc7800 - Manual (Page 9)

Memory DDR2 SYNCH DRAM NON-ECC MEMORY
Memory upgrades are accomplished by adding single or multiple DIMMs of the same or varied
sizes. This chart does not represent all possible memory configurations. The Intel Q35 Express
chipsets support non-ECC DDR2 PC2-5300 (667-MHz) and PC2-6400 (800-MHz) memory.
CAUTION: You must shut down the computer and disconnect the power cord before adding or
removing memory modules. Regardless of the power-on state, voltage is always supplied to the
memory modules as long as the computer is plugged in to an active AC outlet. Adding or removing
memory modules while voltage is present may cause irreparable damage to the memory modules
or system board.
HP recommends dual-channel symmetric configurations for maximum performance.
For best performance, add the same amount of total memory to each channel and do not mix
speeds. For dual-channel symmetric performance, the total amount of memory in each channel
must be equal. If speeds are mixed, speed will default to the slowest DIMM.
Ultra-slim Desktop
Maximum Memory* Supports up to 4 GB of DDR2 SYNCH DRAM. Slot 1 is black and must always be populated. Not
all memory configurations possible are represented below.
NOTE: For systems configured with more than 3 GB of memory and a 32-bit operating system, all
memory may not be available due to system resource requirements.
SO-DIMM Size Slot
Channel A Channel B
1 (black) 2 (white)
512-MB 512-MB
1-GB 1-GB
1-GB (dual channel symmetric) 512-MB 512-MB
2-GB (dual-channel symmetric) 1-GB 1-GB
4-GB maximum (dual channel
symmetric)
2-GB 2-GB
* The Intel Q35 Express chipset includes a built-in Management Engine (ME), which allocates memory for manageability
functions. Management Engine memory is shared with system memory. If the PC contains a single SO-DIMM, 16 MB of
memory is pre-allocated for it at system startup. If the PC contains two SO-DIMMs, 32 MB of memory is pre-allocated. This
memory is not made available to the operating system, just as pre-allocated video memory is not available.
Small Form Factor and Convertible Minitower
Maximum Memory*
Supports up to 8 GB of DDR2 SYNCH DRAM. Slot 1 is black and must always be populated.
Not all memory configurations possible are represented below.
NOTE: For systems configured with more than 3 GB of memory and a 32-bit operating
system, all memory may not be available due to system resource requirements.
Addressing memory above 4 GB requires a 64-bit operating system.
QuickSpecs
HP Compaq dc7800 Business PC
Standard Features and Configurable Components
DA - 12744 Worldwide QuickSpecs — Version 13 — 12.14.2007 Page 9