Dell Precision 490 - Manual (Page 119)

l PCI cards
l Graphics card
l PCI Express cards (if applicable)
At start-up, the BIOS identifies the components that require address space. The BIOS dynamically calculates the amount of reserved address space required.
The BIOS then subtracts the reserved address space from 4 GB to determine the amount of usable space.
l If the total installed computer memory is less than the usable address space, all installed computer memory is available for use only by the operating
system.
l If the total installed computer memory is equal to or greater than the usable address space, a portion of installed memory is not available for use by
the operating system.
Removing Memory
1. Follow the procedures in Before You Begin .
2. Remove the computer cover (see Removing the Computer Cover ).
3. Rotate the hard-drive carrier out of the computer (see Rotating the Hard-Drive Carrier Out of the Computer ).
4. Press out the securing clip at each end of the memory module connector.
5. Grasp the module and pull up to lift the memory module from the memory riser card.
If a module is difficult to remove, gently ease it back and forth to remove it from the connector.
6. Rotate the hard-drive carrier back into place (see Rotating the Hard-Drive Carrier Back into the Computer ).
7. Replace the computer cover (see Replacing the Computer Cover ).
Installing Memory
1. Follow the procedures in Before You Begin .
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
NOTICE: If you remove your original memory modules from the computer during a memory upgrade, keep them separate from any new modules that
you may have, even if you purchased the new modules from Dell. If possible, do not pair an original memory module with a new memory module.
Otherwise, your computer may not start properly.
NOTICE: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your
computer's electronic components. You can do so by touching an unpainted metal surface on the computer chassis
NOTE: Memory purchased from Dell is covered under your computer warranty.
CAUTION: Fully-buffered memory modules may become very hot during normal operation. Ensure that memory modules have had sufficient time
to cool before you touch them.
1 memory module
2 securing clip (2)
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
NOTICE: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your
computer's electronic components. You can do so by touching an unpainted metal surface on the computer chassis.