© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition RAM Chapter 6

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Overview In this chapter, you will learn how to –Identify the different types of DRAM packaging –Explain the varieties of RAM –Select and install RAM –Perform basic RAM troubleshooting

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Program Execution Program code is copied from your hard drive into RAM before it is executed

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Understanding DRAM Dynamic random access memory (DRAM) is the most popular type of electronic memory –Special type of semiconductor that stores ones and zeroes using microscopic capacitors and transistors –Single chip that can hold millions of these capacitor/transistor combinations –Limited width of 1, 4, 8+ bits

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Lab – RAM Observations You will get two sticks of RAM from your instructor On a piece of paper write down five things you observe about the sticks of RAM –Take approximately five minutes to do this

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Understanding DRAM Chips have historically been referenced with respect to their depth and width –256 K × 1 = 256 Kb –1 M × 4 = 2 MB –64 M × 8 = 64 MB You can't tell the width of chip visually

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Organizing DRAM DRAM is considered the standard –Low cost, high speed, and able to store data in a relatively small package –Many varieties of DRAM Early DRAM stored programs and data in 8-bit (1-byte) chunks of memory Individual chips were only 1-bit wide Had to link 8 together to provide 1-byte code

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Memory Controller Chip The memory controller chip (MCC) handles the flow of data from the RAM to the CPU MCC takes care of the physical access CPU doesn’t care if it’s one chip or eight chips!

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DRAM Sticks Individual DRAM chips were difficult to maintain An alternative was needed –Put them on a stick

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition The RAM of Your Ancestors Early RAM types were called Fast Page Mode (FPM) and Extended Data Out (EDO) –Speed measured in nanoseconds –Example: 72-pin SIMM

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition SDRAM Synchronous dynamic RAM (SDRAM) is tied to the system clocks –Synchronized with system clock –Measured in MHz –Comes on DIMM sticks –SO-DIMMs for laptops

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition SDRAM Speeds PC speed rating = Clock speed 133 MHz 100 MHz Clock Speed PC133 PC100 PC66 PC Speed Rating 66 MHz

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DIMM (Dual Inline Memory Module) This is the standard for SDRAM The 168-pin DIMM was very popular for desktops 144-pin SO-DIMMs (small outline) are used in laptops

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition RDRAM RDRAM (Rambus DRAM) is a type of RAM –Speeds of up to 800 MHz –Comes on sticks called RIMMs –184-pin for desktops and 160-pin SO-RIMM for laptops –Dual-channel architecture –All slots must be populated: unused slots must have a CRIMM (continuity RIMM)!

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DDR SDRAM Double Data Rate DDR SDRAM doubles the throughput of SDRAM –184-pin DIMM packages (desktops) ‏ –172-pin micro-DIMM and 200-pin SO-DIMM packages (laptops) ‏ –Wide range of speeds and naming conventions

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DDR Speeds PC4800DDR MHz PC4400DDR MHz PC4000DDR MHz PC3700DDR MHz PC3500DDR MHz 200 MHz 166 MHz 133 MHz 100 MHz Clock Speed PC3200 PC2700 PC2100 PC1600 PC Speed Rating DDR333 DDR200 DDR266 DDR400 DDR Speed Rating PC speed rating = Clock speed × 2 (i.e., doubled) × 8 (i.e., 64-bit data bus)

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Dual-Channel Architecture Uses two sticks of RAM together to increase throughput Works only with paired RAM sticks

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DDR2 SDRAM Doubled the clock, increasing buffering Does not speed up core RAM, but just the I/O 240-pin DIMM (not compatible with DDR) ‏

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DDR2 Speeds 500 MHz 400 MHz 333 MHz 266 MHz 200 MHz DDR I/O Speed PC2-8000DDR MHz 200 MHz 166 MHz 133 MHz 100 MHz Clock Speed PC PC PC PC PC Speed Rating DDR2-667 DDR2-400 DDR2-533 DDR2-800 DDR Speed Rating PC speed rating = Clock speed × 2 × 2 (i.e., doubled twice) × 8 (i.e., 64-bit data bus)

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DDR3 Double the rate of DDR2 240-pin DIMM – not compatible with DDR2 (as shown in the graphic) DDR2 (top) and DDR3 (bottom) sticks

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition DDR3 Speeds 800 MHz 667MHz 533 MHz 400 MHz DDR I/O Speed 200 MHz 166 MHz 133 MHz 100 MHz Clock Speed PC PC PC PC PC Speed Rating DDR DDR3-800 DDR DDR DDR Speed Rating PC speed rating = Clock speed × 2 × 2 × 2 (i.e., doubled three times) × 8 (i.e., 64-bit data bus)

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition RAM Variations Double-sided sticks Latency Parity and error correction code Buffered/Registered –Let's take a look at each one

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Double-Sided DIMMS Almost all sticks come as single-sided or double- sided Your motherboard may or may not be able to accept double-sided sticks

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Latency –Measure of RAM response time –Shown as CLx (x =2 - 9) –Higher the number, the higher the latency –Check motherboard manual for latency limits

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Parity and ECC Parity is a rudimentary method of checking the data to see if errors exist –No error correction, just detection ECC (error correction code) is a special type of RAM used by high-end systems –Major advance in error checking on DRAM –Can also correct many errors –RAM sticks of any size can use the ECC DRAM, but it is most common as 168-pin DIMMs –A motherboard must be designed to use ECC to take advantage of the ECC RAM

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Buffered/Registered DRAM Most motherboards support only four sticks of RAM –More than four sticks present challenges for memory controllers –To overcome these problems, buffering chips are added –Buffering chips as intermediary between RAM and MCC

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Working with RAM What’s wrong with this picture?

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Working with RAM (continued) Avoid ESD damage Don’t touch pins or connectors directly

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Do You Need RAM? Two symptoms point to needing more RAM –General system sluggishness, especially as more programs are opened –Disk thrashing or excessive hard drive accessing, caused by excessive paging Note: Disk thrashing can also be caused by disk fragmentation

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition System RAM Recommendations 2 GB 256 MB 128 MB Reasonable Minimum Windows Vista Windows XP Windows 2000 Operating System 8 GB 2 GB 512 MB Power User 4 GB 256 MB 1 GB Solid Performance Actual minimum requirements are much lower –Usually leads to slower computer and unhappy user

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Determining Current RAM in Windows XP My Computer Properties –WINDOWS KEY- PAUSE/BREAK key Task Manager –CTRL-SHIFT-ESC

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Determining Current RAM in Windows Vista Same as XP Computer Properties –WINDOWS KEY- PAUSE/BREAK key Task Manager –CTRL-SHIFT-ESC

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Getting the Right RAM Identify capacity –What can the motherboard handle (look at the manual) ‏ ? Identify empty slots –If all slots are filled, you’ll have to pull some out –For example, pull out 256-MB sticks to add 512-MB sticks CPU-Z is a great tool to determine what you have –Also shows latency

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Lab – Finding the Right RAM Upgrading RAM is the most common hardware upgrade that people do—and the easiest! You’ll need a motherboard manual and access to the Internet to complete this lab

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Lab – RAM for the PC 1.Consult the motherboard manual to determine type and amount of RAM the system will support 2.Go to one or more of the following Web sites to find the right RAM – – – – If you were going to upgrade the RAM, who has the best price?

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Mix and Match at Your Peril Mixing DRAM speeds can cause the system to lock up, leading to data corruption You can use faster DRAM than the motherboard recommends, but you won’t see an increase in performance You can put different speeds of DRAM in different banks as long as they are both faster than the speed specified

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Installing DIMMs Swing the side tabs away from upright Push the DIMM down somewhat hard… the two tabs should move back into place

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Installing RAM Checklist Get the proper RAM Handle on edges only Don’t touch contacts Power down the PC and unplug it Flip latches open Align RAM groove with slot Insert RAM straight into slot

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Inserting a DIMM

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Lab – Your Turn (Installing RAM) 1.On your motherboard, remove and install the RAM –The act of removing and putting back the RAM is called re-seating the RAM 2.Unplug the PC 3.Take appropriate ESD precautions 4.Flip latches open 5.Remove RAM 6.Handle edges only 7.Don’t touch contacts 8.Align RAM groove with slot 9.Insert RAM straight into slot

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Serial Presence Detect Serial presence detect (SPD) ‏ –Reports the size, speed, data width, and voltage of the installed RAM –MCC knows what to do –CPU-Z shows SPD data

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition The RAM Count Shows at boot Counts addressable RAM and reports it Remember the subtle differences between counting in binary and decimal MB does not equal 512 million exactly

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Installing SO-DIMMs in Laptops Make sure the system is off –No AC connection –Remove all batteries Remove the panel or lift the keyboard Slide the pins into position and then snap the SO-DIMM down into the retaining clips

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Memory Errors Appear as –Parity errors, ECC error messages, system lockups, page faults, and BSoD Real memory errors –“Parity error at xxxxx” –If xxxxx is consistently the same, you have a bad RAM stick. Phantom errors –Random memory addresses –Due to power issues, dust, and heat Page fault

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Non-Maskable Interrupt Blue Screen of Death (BSoD)

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition Testing RAM Hardware RAM testing devices can be used to troubleshoot errors Memtest86 is a freeware tool that can be used to test RAM Vista comes with a memory testing utility on the install disc

© 2010 The McGraw-Hill Companies, Inc. All rights reserved Mike Meyers’ CompTIA A+ ® Guide to Managing and Troubleshooting PCs Third Edition