Tech Chapter 5

Four major categories of memory modules:

1. All new motherboards for desktops sold today use a type of memory module called a DIMM (dual inline memory module).

When installing an AMD processor in AMD socket AM2, AM2+, or other AMD sockets, do the following:

1. Open the socket lever. If there's a protective cover over the socket, remove it.

When installing a processor in socket LGA775, do the following:

1. Push down on the lever and gently push it away from the socket to lift it. Lift the socket load plate. Remove the socket protective cover.

Factors to consider when looking at the overall performance of memory are:

1. The total RAM installed. The more memory there is, the faster the system.

Here is how to work with this socket:

1. To open the socket, press down on the socket lever and gently push it away from the socket to lift the lever. You can then lift the socket load plate. Next, remove the socket protective cover.

Don't allow it to tilt or slide as it goes into the socket. The pins on the bottom of the processor are very delicate, so take care as you work.

3. Check carefully to make sure the pins in the processor are sitting slightly into the holes. Make sure the pins are not offset from the holes.

Socket LGA775 doesn't have those delicate pins that Socket LGA1366 has, but you still need to be careful to not touch the top of the socket or the bottom of the processor as you work.

3. Close the socket cover. Push down on the lever and gently return it to its locked position.

2. Use a ground bracelet or antistatic gloves to protect the processor, motherboard and other components against ESD.

3. Open the socket by pushing down on the socket lever and gently pushing it away from the socket to lift the lever. 4. As you fully open the socket lever, the socket load plate opens.

2. The memory technology used. DDR3 is faster than DDR2. DDR2 is faster than DDR, and DDR is faster than SDRAM.

3. The speed of memory in MHz or PC rating. Use the fastest memory the motherboard supports.

Don't allow the processor to tilt, slide, or shift as you put it in the socket. To protect the pins, it needs to go straight down into the socket.

3. You can now lower the socket load plate and return the lever to its locked position.

3. An older type of module is a RIMM, which is designed by Rambus, Inc.

4. Really old computers used SIMMs (single inline memory module). You're unlikely to ever see these modules in working computers.

4. ECC or non-ECC. Non-ECC is faster and less expensive but might not be as reliable.

5. CL or RL rating. The lower the better.

4. Press the lever down and gently into position.

5. You are now ready to apply the thermal compound and install the cooler assembly. For one system, the black retention mechanism for the cooler is already installed on the motherboard.

Sit the cooler on top of the processor, aligning it inside the retention mechanism.

6. Next, clip into place the clipping mechanism on one side of the cooler. Then push down firmly on the clip on the opposite side of the cooler assembly; the clip will snap into place.

5. Remove the socket protective cover. Keep this cover in a safe place. If you ever remove the processor, put the cover back in the socket to protect the socket. While the socket is exposed, be careful not to touch the pins in the socket.

6. Remove the clear plastic protective cover from the processor. While the processor contacts are exposed, take extreme care to not touch the bottom of the processor. Hold it only at its edges. Put the processor cover in a safe place and use it if you ever remove the processor from the socket.

Later, if you need to remove the cooler, use a Phillips screwdriver to remove the screws holding the retention mechanism in place. Then remove the retention mechanism along with the entire cooler assembly.

7. Connect the power cord from the fan to the 4-pin fan header on the motherboard next to the CPU.

8. Check carefully to make sure the processor is aligned correctly in the socket. It has to be fully seated to close the socket. Close the socket load plate so that it catches under the screw head at the front of the socket.

9. Push down on the lever and gently return it to its locked position.

This value equates to the PC rating of PC6400 for a DDR DIMM.

A DDR2 PC rating is usually labeled PC2, and a DDR3 PC rating is labeled PC3.

DIMM speeds are measured either in MHZ (such as 1333 MHZ or 800 MHz) or PC rating (such as PC6400).

A PC rating is a measure of the total bandwidth of data moving between the module and the CPU. 8 bytes multiplied by 800 MHz, which yields 6400 MB/second.

An I/O (input/output)unit manages data and instructions entering and leaving the processor.

A control unit manages all the activities inside the processor itself.

Some current PC ratings for DDR3 memory are PC-16000 (2000 MHz), PC3-14400 (1800 MHz), PC3-12800 (1600 MHz), and PC3-10600 (1333 MHz).

A couple of current PC ratings for DDR2 memory are PC2-6400 (800 MHz) and PC2-5400 (667 MHz). An older 168-pin SDRAM DIMM might run at PC100 or PC133.

Since the Pentium processor was the first released in 1993, the standard has been for a processor to have two arithmetic logic units (ALU) so it can process two instructions at once.

A processor contains these basic components: an I/O (input/output) unit, a control unit, one or more ALU's (Arithmetic logic units), registers, internal memory caches, and buses inside the processor.

Processors by Advanced Micro Devices, AMD, are popular in the game and hobbyist markets, and are generally less expensive than comparable Intel processors.

AMD processors use different sockets than do Intel processors. The current AMD processor families are the FX, Phenom, Athlon, and Sempron for desktops and the Athlon, Turion, V series, Phenom and Sempron for laptops.

3. Verify the locking pins on the cooler are turned as far as they will go in a counter-clockwise direction. (Make sure the pins don't protrude into the hollow plastic posts that go down into the motherboard holes.)

Align the cooler over the processor so that all four posts fit into the four holes on the motherboard and the fan power cord can reach the fan header on the motherboard.

Synchronized memory runs in step with the processor and system clock,

And its speeds are measured just as processor and bus speeds are measured in MHz.

CAS Latency (CAS stands for "column access strobe") and RAS Latency (RAS stands for "row access strobe"), which are two ways of measuring access timing.

Both features refer to the number of clock cycles it takes to write or read a column or row of data off a memory module. CAS Latency is used more than RAS Latency. Lower values are better than higher ones.

Internal memory caches (L1, L2, and possibly L3) hold data and instructions waiting to be processed by ALU.

Buses inside the processor connect components within the processor housing. These buses run at much higher frequency than the Front Side Bus (FSB) that connects the processor to the chipset and memory on the motherboard.

If the system comes up and begins the boot process,

But suddenly turns off before the boot is complete, most likely the processor is overheating because the cooler is not installed correctly.

Memory features on the motherboard that the processor can support: type, amount, speeds and number of memory channels.

Current types of D-RAM memory modules are DDR, DDR2 or DDR3. Number of memory channels are single, dual, triple or quad channels.

Double Data Rate SDRAM (DDR SDRAM, or SDRAM II, or simply DDR) is an improved version of SDRAM.

DDR runs twice as fast as regular SDRAM, has one notch, and uses 184 pins. Instead of processing data for each beat of the system clock, as regular SDRAM does, it processes data when the beat rises and again when it falls, doubling the data rate of memory.

DDR, DDR2, and DDR3 DIMMs can use dual channels.

DDR3 DIMMs can also use triple channels and quad channels. For dual, triple, or quad channels to work, the motherboard and the DIMM must support the technology.

The major differences among these modules are the width of the data path that each type of module accommodates and the way data moves from the system bus to the module.

DIMMs have seen several evolutions. Notice the notches on the modules, which prevent the wrong type of module from being inserted into a memory slot on the motherboard.

Intel's current families of processors for the desktop include the Core, Atom, Celeron, and Pentium families of processors. Also, they are group into Third generation, Second generation, and Previous Generation processors.

Each generation improves on how the processor and chipset are integrated in the system. You can purchase a processor with or without a cooler. When it's purchased with a cooler, it's called a boxed processor. If you purchase the cooler separately, make sure it fits the socket you are using.

Processor Frequency is the speed at which the processor operates internally. Multiplier is the factor that multiply by the FSB (Front Side Bus) = processor frequency. See processor frequency in BIOS setup screen.

Example: processor frequency 3.2GHz, FSB 800 MHZ, Multiplier 4. 800 MHz x 4 = 3.2 GHz. You can change the multiplier or the clock speed to overclock or throttle the processor.

Feature 2: Processor speed. Processor core frequency is measured in gigahertz such as 3.3GHz.

Feature 3: What socket and chipset the processor can use. Intel sockets are PGA988, LGA2011, LGA 1155, LGA1156, LGA1366 and LGA 775. AMD sockets are AM3+, AM3, AM2+, AM2, FM1, F and 940

Feature 4: Processor architecture (32 bits and 64 bits). All Intel or AMD processors are hybrid, which can process 64 bits or 32 bits at a time. Older processors only handled 32 bit OS. Most Window 7 come in either type.

Feature 5: Multiprocessing abilities. The ability to do more than one thing is accomplished by several means: a. Multiprocessing b. Dual processors c. Multi-core processing d. Multithreading

Before installing the cooler, read the directions carefully. Clips that hold the fan and heat sink to the processor frame or housing are sometimes difficult to install.

Follow these general steps: 1. The motherboard has four holes to anchor the cooler. Examine the cooler posts that fit over these holes and the clips, screws or wires that hold the cooler firmly in place , and how this mechanism works.

When replacing a processor in an existing system, power down, unplug the power cord, press the power button to drain the system power and open the case.

Follow these steps to install the processor and cooler using socket LGA1155: 1. Read all directions in the motherboard user guide and carefully follow them on order.

Also check in BIOS setup the CPU and motherboard temperatures to verify the CPU is not overheating.

For one BIOS setup in another system, this screen is under the Configuration menu, Fan Control & Real-Time Monitoring window.

2. Holding the processor very carefully so you don't touch the bottom, orient the four empty positions on the bottom with the four empty positions in the socket.

For some AMD sockets, a gold triangle on one corner of the processor matches up with a small triangle on a corner of the socket. Carefully lower the processor into the socket.

7. Hold the processor with your index finger and thumb. The gold triangle on the corner of the processor should line up with the right angle mark on the motherboard just outside a corner of the socket.

Gently lower the processor straight down into the socket. Don't let the processor to tilt, slide or shift as you put it in the socket. To protect the pads, it needs to go straight down into the socket.

2. Orient the processor so that the notches on the two edges of the processor line up with the two notches on the socket.

Gently place the processor in the socket.

A memory bank is the memory a processor addresses at one time and is 64 bits wide, and a DIMM slot provides a 64-bit data path.

However, some double-sided DIMMs provide more than one bank, which means the chips on the DIMM are grouped so that the memory controller addresses one group and then addresses another. These DIMMs are said to be dual ranked, and don't perform as well as DIMMs where all the memory is addressed at one time.

With RIMMs, each memory slot on the motherboard must be filled to maintain continuity throughout all slots.

If a slot does not hold a RIMM, it must hold a placeholder module called a C-RIMM (Continuity RIMM) to ensure continuity throughout all slots. The C-RIMM contains no memory chips.

Installing an Intel Core i5-2320 processor in socket LGA1155

If the motherboard is not already install in the case, read directions from manufacturer to install the motherboard and then the processor or to install the processor and then the motherboard.

Later, when the byte is read back, the memory controller checks the odd or even state.

If the number of bits is not an odd number for odd parity or an even number for even parity, a parity error occurs. Parity Error 1 is a parity error on the motherboard; Parity Error 2 is a parity error on an expansion card. A SIMM appears in a memory ad as EDO memory.

Make one last check to verify all power connectors are in place and other cords and cables connected to the motherboard are correctly done. You are now ready to plug back up the system, turn it on, and verify all is working.

If the power comes on (you hear the fan spinning and see lights), but the system fails to work, most likely the processor is not seated solidly in the socket or some power cord has not yet been connected or is not solidly connected.

ECC compares bits written to the module to what is later read from the module, and it can detect and correct an error in a single bit of the byte.

If there are errors in two bits of a byte, ECC can detect the error but cannot correct it.

Intel makes several 64-bit processors for workstations or servers that use fully implemented 64-processing, including Itanium and Xeon processors.

Intel calls the technology IA64 or x64-bit processors. They require 64-bit operating system and can handle 32-bit applications only by stimulating 32-bit processing.

Random access memory (RAM)

Is stored on memory modules, which are installed in memory slots on the motherboard.

To use dual channeling, matching DIMMs must be installed in the black slots and another matching pair in the blue slots.

Know that the second pair of DIMMs does not have to match the first pair of DIMMs because the first channel runs independently of the second channel. If the two DIMM slots of a channel are not populated with matching pairs of DIMMs, the motherboard will revert to single channeling.

Feature 6: Memory cache, which is the amount of memory included within the processor package. Level 1 cache (L1cache) is the memory on the processor chip, called a die.

Level 2 cache (L2 cache) is memory in the processor package, but not on the processor die. Level 3 cache (L3 cache) is a third cache further from the processor core but still in the processor package.

The installations of all processors and sockets in this part of the chapter are similar to that of installing a processor in Socket LGA1155.

Listed next are the differences when installing a processor in the LGA1366 socket. These socket pins are delicate, so work slowly and take care.

After the system is up and running, you can check BIOS setup to verify that the system recognized the processor correctly.

Look for items on the screen that manage processor features, and make sure each is set correctly.

After the processor and cooler are installed and the motherboard is installed in the case,

Make sure cables and cords don't obstruct fans or airflow, especially airflow around the processor and video card. Use cable ties to tie cords and cables up and out of the way.

2. Laptops use a smaller version of a DIMM called a SO-DIMM (small outline DIMM and pronounced "sew-dim").

MicroDIMMs are used on subnotebook computers and are smaller than SO-DIMMs.

A DIMM can have memory chips installed on one side of the module (called single-sided) or both sides of the module (called double-sided).

Most desktop and laptop processors address memory 64 bits at a time.

If you see the processor temperature rising and reaching 80 degrees, open the case cover and verify the processor fan is running.

Perhaps a wire is in the way and preventing the fan from turning or the fan wire is not connected.

Third Generation, Ivy Bridge, processors: core i7and core i5. Second Generation, Sandy Bridge, processors: core i7 extreme, core i7, core i5, core i3 and Pentium

Previous Generation processors: core i7 extreme, core i7, core i5, core i3, atom, Celeron, Celeron desktop, Celeron D, core 2 extreme, core 2 quad, core 2 duo, Pentium extreme, Pentium, Pentium 4, and Pentium D.

In a quad-core processor, each core has its own independent internal L1 and L2 cache. L1 is on the die, and L2 is off the die. All cores might share L3 cache from the processor package.

Prior to the memory controller being in the processor package, it was part of the North Bridge chipset. Putting the memory controller inside the processor package resulted in a significant increase in system performance.

These older 32-bit processors are known as x86 because Intel used this number for this model. You must use a 32-bit version of Windows. These computers can handle only 32-bit instructions from OS.

Processors that can process 32-bit or 64-bit are called hybrids, and are known as x86-64-bit processors. AMD was the first one to produce one, the Athlon 64, and called AMD64. Intel Pentium 4 technology is called Extended Memory 64 Technology.

Even though an older RAM technology is no longer used by new motherboards,

RAM manufacturers continue to produce the older RAM because older motherboards require these replacement modules. All new motherboards today use DIMMs.

Direct Rambus DRAM (sometimes called RDRAM or Direct RDRAM or simply Rambus) is called a RIMM.

RIMMs are expensive and are now slower than current DIMMs. No new motherboards are built to use RIMMs.

RIMMs that use a 16-bit data bus have two notches and 184 pins.

RIMMs that use a 32-bit data bus have a single notch and 232 pins. The 232-pin RIMMs can support dual channels. RIMMs can be ECC or non-ECC and vary in size and speed.

ALU's (arithmetic logic units) do all logical comparisons and calculations inside the processor. All desktop and laptop processors sold today have two ALU's.

Registers, which are small holding areas on the processor chip, work much like RAM does outside the processor to hold counters, data, instructions and addresses that ALU is currently processing.

Don't confuse SDRAM with SRAM.

SRAM is static RAM used in processor memory caches, and SDRAM is dynamic RAM used on DIMMs.

A motherboard that supports triple channels can access three DIMMs at the same time.

Sandy Bridge technology introduced quad channels where the processor can access four DIMMs at the same time.

Buffers and registers hold data and amplify a signal just before the data is written to the module. (Using buffers is an older technology than using registers.)

Some DIMMs use buffers, some use registers, and some use neither. If a DIMM doesn't support registers or buffers, it's referred to as an unbuffered DIMM.

Error-checking technology is called ECC (error-correcting code).

Some SDRAM, DDR, DDR2, and DDR3 memory modules support ECC. A DIMM normally has an even number of chips on the module, but a DIMM that supports ECC has an odd number of chips on the module. The odd extra chip is the ECC chip.

Feature 9: Integrated graphics. A Graphic Processing Unit (GPU) is a processor that manipulates graphic data to form the images on a monitor screen.

The GPU might be on a video card, on the motherboard, or place in the CPU package. When inside the CPU package, it's called integrated graphics. Many AMD processors and all Intel second and third generation processors have integrated graphics.

The data path width for DIMMs is normally 64 bits, but with ECC, the data path is 72 bits.

The extra 8 bits are used for error checking. ECC memory costs more than non-ECC memory, but it is more reliable.

JEDEC (www.jedec.org) is the organization responsible for standards used by solid state devices, including RAM technologies.

The goal of each new RAM technology approved by JEDEC is to increase speed and performance without greatly increasing the cost.

Notches on SDRAM DIMMs are positioned to identify the technologies that the module supports. The position of the notch on the left identifies the module as registered (RFU), buffered, or unbuffered memory.

The notch on the right identifies the voltage used by the module. The position of each notch not only helps identify the type of module but also prevents the wrong kind of module from being used on a motherboard.

For a triple-channel installation, three DIMM slots must be populated with three matching DDR3 DIMMs.

The three DIMMs are installed in the three blue slots on the board. If the fourth slot is used, then triple channeling is disabled, which can slow down performance. Dual channels are not as fast as triple channels, but certainly better than single channels.

DIMMs use a 64-bit data path. A DIMM (dual inline memory module) gets its name because it has independent pins on opposite sides of the module.

Their speeds are measured in nanoseconds (ns), which is how long it takes for the module to read or write data. The first DIMM to run synchronized with the system clock was synchronous DRAM (SDRAM), which has two notches, and uses 168 pins.

There are two major manufacturers of processors: Intel and AMD.

There are nine features of processors that affect performance and compatibility with motherboard:

DDR2 is faster and uses less power than DDR. DDR3 is faster and uses less power than DDR2. Both DDR2 and DDR3 use 240 pins, although their notches are not in the same position.

They are not compatible, and the different notch positions keep someone from installing a DDR2 or DDR3 DIMM in the wrong memory slot. Factors that affect the capacity, features, and performance of DIMMs include the number of channels they use, how much RAM is on one DIMM, the speed, error-checking abilities, and buffering.

The DIMM slots are different colors.

This color coding is used to identify the channel each slot uses. Channels have to do with how many DIMM slots the memory controller can address at a time.

When selecting a processor, the first requirement is to select one that the motherboard is designed to support. Select the best that meets the general requirements of the system and the user's needs.

To get the best performance, select the highest-performing processor the board supports. Sometimes you need to sacrifice performance for cost.

The latest memory technology is quad channeling that was introduced with Intel Sandy Bridge chipsets and processors. The processor can access four slots at the same time. The four black slots can be addressed by the processor on one memory channel and the four blue slots on another channel.

To get the highest performance, memory slots are placed on either side of the processor in order to shorten the length of the memory bus. Because of the high performance of processors that use the LGA2011 socket, Intel recommends that systems using this socket use liquid cooling methods.

4. Push down on each locking pin until you hear it pop into the hole.

To help keep the cooler balanced and in position, push down two opposite pins and then push the remaining two pins in place. Using a flathead screwdriver, turn the locking pin clockwise to secure it.

Early DIMMs only used a single channel, which means the memory controller can access only one DIMM at a time.

To improve overall memory performance, dual channels allow the memory controller to communicate with two DIMMs at the same time, doubling the speed of memory access.

6. Single, dual, triple, or quad channeling.

To improve performance, use dual, triple, or quad channeling if the board supports the feature. To use dual, triple, or quad channeling, install matching DIMMs from the same manufacturer in each group of channel slots.

All desktop or laptop processors sold today either from Intel or AMD contain ALUs and registers that can process 32 bits or 64 bits at a time.

To know which type of operating system to install, you need to be aware of three categories of processor currently used: 32-bit, 32-bit or 64-bit, and 64-bit processors.

5. Connect the power cord from the cooler fan

To the motherboard power connector near the processor.

When removing and reinstalling a processor,

Use a soft dry cloth to carefully remove all the old thermal compound from both the processor and the cooler. Don't try to reuse the compound.

Older SIMMs used an error-checking technology called parity.

Using parity checking, a ninth bit is stored with every 8 bits in a byte. Parity memory uses 9 bits (8 bits for data and 1 bit for parity).

Feature 8: Support for virtualization. Most computers sold today support virtualization and must be enable in BIOS setup.

Virtualization is when a computer can use a software to create and manage multiple virtual machines that contain virtual devices.

2. If the cooler has thermal compound pre-applied, remove the plastic from the compound. If the cooler doesn't have thermal compound applied, put a small dot of compound (a size of a small pea) in the center of the processor.

When the cooler is attached and the processor is running, the compound spreads over the surface. Individual packets content a single application of the thermal compound. Excessive compound will damage the processor and circuits on the motherboard.

If you try to use the lever to put pressure on these pins and they are not aligned correctly, you can destroy the processor.

You can actually feel the pins settle into place when you're lowering the processor into the socket correctly.

2. To install the processor, hold the processor with your index finger and thumb and orient the processor so that the notches on the two edges of the processor line up with the two posts on the socket.

You can see the notch and post on the right side of the processor and socket. Gently lower the processor straight down into the socket.

For ECC to work, the motherboard and all installed modules must support it.

You cannot install a mix of ECC and non-ECC memory because the system doesn't work. To see if your motherboard supports ECC memory, look for the ability to enable or disable the feature in BIOS setup, or check the motherboard documentation.

To handle two threads, the processor requires extra registers or holding areas, within the processor housing that it uses to switch between threads.

You have two logical processors for each physical processor or core. This feature must be enabled in BIOS setup. Intel calls this technology Hyper-Threading, and AMD calls it Hyper-Transport.

If you later notice the CPU fan is running far too often,

You might need to tighten the connection between the cooler and the processor.

On a motherboard, the connectors inside the memory slots are made of tin or gold, as are the edge connectors on the memory modules. It used to be that all memory sockets were made of tin, but now most are made of gold.

You should match tin leads to tin connectors and gold leads to gold connectors to prevent a chemical reaction between the two medals, which can cause corrosion. Corrosion can create intermittent memory errors and even make the PC unable to boot.

Feature 1: Clock speed the processor supports. Intel and AMD processors work with system buses that run

at 1.8 GHz up to more than 3.4GHz. The smaller the processor multiplier, the faster the system bus runs in comparison to the processor speed.

a. Multiprocessing is when two processing units called ALU's (arithmetic logic units) are installed within a single processor. Pentium was the first processor that could execute two instructions at the same time.

b. Dual processors or a multiprocessor platform is when a server motherboard might have two processor sockets.

c. Multi-core processing is when multiple processors (a package might contain up to 8 cores) can be installed in the same processor housing.(dual-core, triple- quad, and so forth)

d. Multithreading is when a processor or core processes two threads (when windows hands off a task to the CPU) at the same time, and each thread might involve several instructions.

Intel processors vary in performance and functionality. To help identify a processor, Intel uses a processor number, such as i7-940 and i7-920 for two core i7 processors. Some of the Intel mobile processors, laptops, are packaged

in the Cetrino processor technology: the Intel processor, chipset and wireless network adapter are all interconnected as a unit, which improves laptop performance. Intel's smallest processor, Atom processor, is used in low-cost PC's, laptops, and netbooks.

Memory used in a memory cache is static RAM or S-RAM. Memory used on the motherboard loses data rapidly, and

must refreshed often. It's called volatile memory or dynamic RAM or D-RAM. S-RAM is faster than D-RAM because it doesn't need refreshing; it can hold its data as long as power is available.