Chapter 4 Exercises
Multiple Choice
Select the best answer.
1. What are the two possible numbers of pins on a DIMM?
a. 168 or 184
b. 30 or 72
c. 184 or 232
d. 128 or 256
2. ______________ is DRAM that runs in sync with the system clock and thus runs
faster than other types of DRAM.
a. SIMM
b. Synchronous DRAM
c. Asynchronous DRAM
d. RIMM
3. Instead of using parity checking, newer memory uses a method of error checking
called ___________.
a. mapping
b. nonparity
c. non-EKG
d. ECC (error-correcting code)
4. How many notches are on a DDR SDRAM module?
a. one
b. two
c. four
d. six
5. Under Windows 2000 and Windows XP, the default size of the paging file is set to
___ times the amount of RAM installed.
a. 128
b. 2
c. 1.5
d. 16
Answers
1. a
2. b
3. d
4. a
5. c
Fill-in-the-Blank
Write the word or phrase to fill in the blank in each of the following
questions.
1. Memory caching relies on SRAM chips to store data and a ____________ to
manage the storage and retrieval of data from SRAM.
2. Instead of processing data for each beat of the system clock like regular SDRAM,
_______________ processes data twice for each beat, thus doubling the data rate of
memory.
3. Computers use one or two methods to detect memory: ___________, which uses
resistors to communicate the type of memory present, or_____________, which
stores information about the memory type in ROM.
4. Ads for DIMMs often list the ________ of the module, which is written as two
numbers separated by an X, such as 16X64.
5. DRAM is refreshed by the ____________, is a circuit in the chip set on the
motherboard that control the reading and writing of information from and to the
memory.
Answers
1. cache controller
2. Double Data Rate SDRAM (DDR SDRAM) or DDR or SDRAM II
3. Parallel Presence Detect (PPD), Serial Presence Detect (SPD)
4. density
5. memory controller
Matching Terms
Match the terms with their definitions.
_i_ 1. bank
_f_ 2. SIMM
_e_ 3. refresh
_d_ 4. virtual memory
_h_ 5. DIMM
_j_ 6. PC100
_a_ 7. C-RIMM
_c_ 8. extended
memory
_b_ 9. RIMM
_g_ 10. Pagefile.sys
a. placeholder module used with RIMMs to ensure
continuity throughout all slots
b. memory module that houses RDRAM chips
c. memory above 1024K used in DOS or Windows 9x
d. method of using the hard drive as though it were RAM
e. process of rewriting the data to the RAM chip.
f. memory module with pins on opposite sides of the circuit
board that form a single set of contacts
g. swap file used by Windows 2000 and Windows XP
h. memory module with pins on opposite sides of the
circuit board that form two sets of contacts
i. a location on the motherboard that contains slots for
memory modules
j. speed of memory module that will work with a
motherboard that runs at 100 MHz
Short Answer Questions
Write a brief answer to each of the following questions.
1. If your motherboard supports DIMM memory, will RIMM memory work on the
motherboard?
2. If your motherboard supports ECC SDRAM memory, can you substitute SDRAM
memory that does not support ECC? If your motherboard supports buffered
SDRAM memory, can you substitute unbuffered SDRAM modules?
3. List at least four things you can do if you receive memory errors during a
memory upgrade.
4. List at least four things you can do if you receive memory errors during normal
operation when you have not recently upgraded memory.
5. What are factors, in addition to speed, that determine how fast memory runs?
Answers
1. No, you can only use the type of memory module the board is designed to
support.
2. You can substitute non-ECC memory on an ECC board, and the error-checking
feature will be shown disabled in CMOS. You cannot use unbuffered SDRAM on a
motherboard that supports buffered memory, as evidenced by the fact that the
notches on buffered DIMMs are in different positions than for unbuffered DIMMs.
3. Possible answers are:
 Check that you have the right memory modules supported by your
motherboard.
 Check that you have installed the right module size, as stated in the
motherboard documentation. Verify each module that was already
installed or newly installed.
 Remove and reinstall each module. Confirm that the memory modules are
properly seated, and that each module sits in the socket at the same
height as other modules.
 Remove the newly installed memory, place the memory in different
sockets or slots, and check whether the error message disappears.
 Try installing the new memory without the old installed. If the new
memory works without the old, then the problem is that the modules are
not compatible.
 Clean the module edge connectors with a soft cloth or contact cleaner.
Blow or vacuum dust from the memory sockets.
 Try flashing your BIOS. It is possible the BIOS has problems with the new
memory that a BIOS upgrade can solve.
4. Possible answers are:
 Run a current version of antivirus software to check for viruses.
 The problem might be with the OS or applications. Download the latest
patch your operating system and application software from the
manufacturer’s Web site.
 If you have just installed new hardware, the hardware device might be
causing an error, which the OS interprets as a memory error. Try
uninstalling the new hardware.
 A Windows error that occurs randomly and generates an error message
with exception fault 0E at >>0137:BFF9z5d0 or similar text is probably a
memory error. Test, reseat, or replace RAM.
 Sometimes a problem can result from a bad socket or a broken trace (a
fine printed wire or circuit) on the motherboard. Check the motherboard
for visible problems. If you find an issue, you might have to replace the
entire motherboard.
 If errors continue to occur, keep a record of what you are doing when the
error message displays or issue occurs in order to help narrow down the
source of the issue.
5. Several factors contribute to how fast memory runs, and speeds are measured in
different ways. Factors to consider when looking at the overall speed of memory
are shown in the include:
 The speed of memory. Memory speeds are measured in ns, MHz, or PC
rating.
 The amount of memory installed. The more memory there is, the faster
the system.
 The memory technology used. DDR is faster than SDRAM; RDRAM is faster
than SDRAM. When selecting memory, use whatever technology your
motherboard supports.



The latency rating. CAS Latency is used more than RAS Latency. CL2 (CAS
Latency 2) is a little faster than CL3 (CAS Latency 3). A lower latency
rating means memory is faster.
The type of error checking used. Parity refers to an error-checking
procedure in which a ninth, or parity bit, is added. Older DRAM memory
used parity checking, but today’s memory uses a new method of error
checking called ECC (error-correcting code). ECC memory costs more than
regular memory and is slower because of the extra time taken to verify
data, but it is more reliable.
Single channel versus dual channel. Memory can be used in single-channel
mode or dual-channel mode. Single-channel memory modules are
accessed through a single channel or connection between the memory
controller and the memory module. With dual-channel memory, the
memory controller reads from or writes to two memory modules, each on
separate channels, simultaneously.