Chapter 4: RAM
Will you every need to configure the page file in Windows?
You can run into problems that require you to change the size of the page file or delete it and let Windows re-create it automatically File name: pagefile.sys Found in root directory of C: drive usually (it's a hidden system file so you may need to play with folder to see it) If Windows has to move programs between page file and RAM a lot, hard drive LED will go crazy
What is a non-maskable interrupt (NMI)?
interruption the CPU cannot ignore, causes the computer to. shut down before saving manifests as a proprietary crash screen and requires the machine to be restarted Bad RAM can trigger NMI but usually the culprit is buggy programing or clashing code
Micro-DIMM
micro dual inline memory module
What is a page fault
milder than system lock up that can be caused by memory issues but not always RAM Look like RAM issues as Windows Error messages are filled with complicated syntax write the error message down, if it repeats then you have a bad RAM stick if displays multiple memory locations, the problem is elsewhere
What is disk thrashing
Windows rushes to move programs between page file and RAM If there is excessive disk thrashing, you need more RAM
What is triple channel and quad channel architecture
Work like dual channel but with 3 or 4 sticks instead of 2 Most systems have gone back to 2 channel but this does exist (review this for exam)
What is random access memory (RAM)?
When a program isn't in use, it is saved in a mass storage device. When it is in use, a copy is loaded into RAM and RAM runs it
How to mix RAM speeds
the safest easiest route tp follow is to use the speed of DRAM specified in motherboard book and make sure every piece of DRAM runs at that speed Mixing can cause a system to lock up badly and risks data corruption don't trust until system has proven stable for a few days (only can break data, not hardware from experimenting) Can mix speeds so long as they are as fast or faster than motherboard speed Don't bother trying to put different speed DRAM sticks in the same bank with motherboard that uses dual channel DDR2
What form factors do modern DRAM sticks come in?
32 and 64 bit-wide with a varying number of chips. They can be described as x32 and x64. This number does NOT describe the width of the individual DRAM chips on the module. Make sure when someone is talking about "by whatever," you know whether they are talking about DRAM width or module width
What is a sealed system?
A system that you cannot make any upgrades, like a MAC or a phone. What you buy is what you're stuck with.
How does an NMI manifest on a Windows system A. Blue screen of death B. Spinning pinwheel of death C. Interrupt of death D. NMIs only happen on macOS systems
A. A non-maskable interrupt on a Windows system often results in the Blue Screen of Death
Cindy installed a second stick of DDR4 RAM into her Core i5 system, brining the total system memory up to 16 GB, Within a short period of time, though, she beings experiencing the Blue Screen of Death. What could the problem be? A. She installed faulty RAM B. The motherboard could only handle 12 GB of RAM C. The motherboard needed dual-channel RAM D. There is no problem. Windows always does this initially but gets better after crashing a few times
A. If you have no problems with a system and then experience problems after installing something new, chances are the something new is at fault
Steve adds a second 8-GB 288-pin DIMM to his PC, which should bring the total RAM in the system up to 16 GB. The PC has an Intel i7 4-GHz processor and four 288-pin DIMM slots on the motherboard. When he turns on the PC, however, only 8 GB of RAM shows up in the Windows Settings app. Which of the following is most likely to be the problem? A. Steve failed to seat the RAM properly B. Steve put DDR4 in a DDR3 slot C. The CPU cannot handle 16 GB of RAM D. The motherboard can only use one RAM slot at a time
A. Steve failed to seat the RAM properly
What is the best way to determine the total capacity and specific type of RAM your system can handle? A. Check the motherboard book B. Open the case and inspect the RAM C. Check the Device Manager D. Check the System utility in the Control Panel
A. The best way to determine the total capacity and specific type of RAM you system can handle is to check the motherboard book
Which of the following Control Panel applets will display the amount of RAM in your PC? A. System B. Devices and Printers C. Device Manager D. Action Center
A. You can use the System applet to see how much RAM is currently in your PC
How to install DIMMs
Attach anti-static wrist strap pr touch some bare metal on the power supply to ground yourself Swing the side tabs on RAM slots down from upright. position Pick up stick of RAM- don't touch the contacts- and line up the notches with raised portions of. DIMM socket Make sure the DIMM snaps into position to show it completely seated Motherboard should automatically detect and set up on any DIMM you installed if right RAM using serial presence detect (SPD)
What is double data rate SDRAM (DDR SDRAM)
Alternative to RDRAM, it copies RDRAM, doubling throughput of SDRAM by making two processes for every clock cycle (synced with AMD processors). Not as fast as RDRAM but was an improvement and only cost slightly more than SDRAM. Comes in 184 pin DIMM for desktop (same size as 168 pin but not in pin ability) For laptops, comes in 200 pin SO-DIMMS or 172 pin Micro DIMMS
What does DRAM look like?
As CPU data bus size increased there became a need for. RAM wide enough to fit it. Manufacturers would make wider DRAM chips and put multiples on a small. circuit board called a stick or module
What is Mac system RAM requirements
Bare minimum: 2 GB of RAM A 64 bit OS does better with more RAM 4 GB minimum, 8 GB for good performance and more for peak performance
What is the primary reason that DDR4 RAM is faster than DDR3 RAM? A. The core speed of the DDR4 RAM chips is faster B. The input/output speed of the DDR4 RAM is faster C.DDR3 RAM is dual-channel and DDR4 RAM is quad-channel D. DDR3 RAM uses 240 pin DIMMs and DDR4 uses 288 pin DIMMs
B. The input/output speed of DDR4 RAM is faster than that of DDR3 RAM (although the latency is higher)
What is Windows system RAM requirements
Bare minimum: Microsoft recommends requirement of 1 GB of RAM for 32. bit and 2 GB for 64 bit Good recommendations: 32 Bit Windows: 2 GB to get by, 4 GB for best results 64 Bit Windows: 4 GB to get by , 6 GB for solid machine and 16+GB for any machine doing serious, processor. intensive work
What is the naming convention for DDR sticks
Based on number of bytes per second of data throughput the RAM can handle determine bytes per second by taking the MHz speed and multiplying by 8 bytes (the width of all DDR SDRAM sticks) EX: 400 MHz x 8 = 3200 megabytes per second. Then put "PC" in front to make PC3200 Can also be used to refer to individual DDR chips EX: DDR400 refers to 400 MHz DDR SDRAM chip running on a 20 MHz clock Note: DDRxxx refers to individual DDR chips PCxxxx is for DDR sticks
What is DDR3
Boasts higher speeds, more efficient architecture and around 30 percent lower power consumption than DDR2 RAM Uses 240pin DIMM but slotted differently to make it difficult for users to install the wrong thing the SO-DIMMS for laptops have 204 pins and don't fit into a DDR2 socket Doubles the buffer of DDR2 from 4 bits to 8 bits, giving huge boost in bandwidth
What is the term for the delay in the RAM's response to a request from the MCC? A. Variance B. MCC gap C. Latency D. Fetch interval
C. Latency is the term for the delay in the RAM's response to a request from the MCC
Gregor installed a third stick of known good RAM into his Core i7 system, bringing the total amount of RAM up to 12 GB. Within a. few days, though, he started having random lockups and reboots, especially when doing memory-intensive tasks such as gaming. What is most likely the problem? A. Gregor installed DDR2 RAM into a DDR3 system B. Gregor installed DDR3 RAM into a DDR4 system C. Gregor installed RAM that didn't match the speed or quality of the RAM in the system D. Gregor installed RAM that exceeds the speed of the RAM in the system
C. Most likely, Gregor installed RAM that didn't match the speed or quality of the RAM in the system
What is column array strobe latency (CAS)
CL17 and CL19 are the initials, is how many clock cycles in it takes for the RAM module to access a specific set of data in one of its columns (hence the name) and make that data available on its output pins, starting from when a memory controller tells it to.
How do you determine RAM capacity
Check control panel (Windows-Pause/Break keystroke) Performance tab in Task Manager (CTRL-SHIFT-ESC and select Performance Tab) Included info about amount of RAM being used
Clock speeds, DDR speed rating and PC speed rating chart
Clock Speed DDR Speed Rating PC Speed Rating 100MHz DDR-200 PC-1600 133MHz DDR-266 PC-2100 166MHz DDR-333 PC-2700 200MHz DDR-400 PC-3200 217MHz DDR-433 PC-3500 233MHz DDR-466 PC-3700 250MHz DDR-500 PC-4000 275MHz DDR-550 PC-4400 300MHz DDR-600 PC-4800
DDR4 PC4 clock speeds chart
Clock. Bandwidth. DDR4 Speed. PC Speed Speed. Rating Rating 200MHz. 1600MT/s. DDR4-1600. PC4-12800 266MHz. 2133MT/s. DDR4-2133. PC4-17000 300MHz. 2400MT/s. DDR4-2400. PC4-19200 400MHz. 3200MT/s. DDR4-3200. PC4-25600 Skipping a bunch in the middle 563MHz. 4500MT/s. DDR4-4500. PC4-36000 575MHz. 4600MT/s. DDR4-4600. PC4-36800 588MHz. 4700MT/s. DDR4-4700. PC4-37600
Core RAM clock speeds and DDR/DDR2 speed ratings chart
Core RAM DDR I/O DDR2 PC Speed Clock Speed Speed Sped Rating Rating 100MHz 200MHZ DDR2-400 PC2-3200 133MHz 266MHz DDR2-533 PC2-4200 166MHz 333MHZ DDR2-667 PC2-5300 200MHz 400MHz DDR2-800 PC2-6400 266MHz 533MHz DDR2-1066 PC2-8500
DDR3 PC3 clock speeds chart
Core RAM. DDR I/O. DDR3. PC Speed Clock Speed. Speed. Speed Rating Rating 100MHz 400MHz. DDR3-800. PC3-6400 133MHz. 533MHz. DDR3-1066. PC3-8500 166MHz 667MHz. DDR3-1333. PC3-10667 200MHz. 800MHz. DDR3-1600. PC3-12800 233MHz 933MHz. DDR3-1866. PC3-14900 266MHZ 1066MHz. DDR3-2133 PC3-17000 300MHz 1200MHz. DDR3-2400. PC3-19200
Silas has an AMD-based motherboard with two sticks of DDR2 RAM installed in two of the three RAM slots, for a total of 2 GB of system memory. When he runs CPU-Z to test the system, he notices that the software claims he's running single-channel memory. What could be the problem? (Select the best answer.) A. His motherboard only supports single-channel memory. B. His motherboard only supports dual-channel memory with DDR RAM, not DDR2. C. He needs to install a third RAM stick to enable dual-channel memory. D. He needs to move one of the installed sticks to a different slot to activate dual-channel memory.
D. Motherboards can be tricky and require you to install RAM in the proper slots to enable dual-channel memory access. In this case, Silas should move one of the installed sticks into a different slot to activate dual-channel memory (And he should check the motherboard manual for the proper slots)
Scott wants to add 8 GB of PC3-12800 DDR3 to an aging but still useful desktop system. The system has a 200-MHz motherboard and currently has 4 GB of non-ECC DDR3 RAM in the system. What else does he need to know before installing? A. What speed of RAM he needs B. What type of RAM he needs C. How many pins the RAM has D. If the system can handle that much RAM
D. Scott needs to know if the system can handle that much RAM
What is DDR2
DDR RAM with improvements in its electrical characteristics, enabling it to run even faster than DDR while using less power Big speed increase comes from double-clocking the input/output circuits on the chips. The core RAM is not sped up, speeds up the input and output and adding special buffers (sort of like a cache) Uses 240pin DIMM that's not compatible with DDR DRR2 DIMMS are not compatible with DDR Motherboards can either run single-channel or dual-channel DDR2
How do DDR3 and DDR2 speeds compare to clock speeds?
DDR3 I/O speeds are quadruple the clock speeds DDR2 I/O speeds are double the clock speeds The increase in speed between DDR3 and DDR2 is due to an increase in buffer size
What is DDR3L and DDR3U
DDR3L is the low voltage version of DDR3, providing major cost savings in massive RAM applications Runs at 1.35 volts compared to 1.5 or 1.65 of regular DDR3 DDR3U is the ultra low voltage version and it runs at 1.25 volts These produce less heat The DIMM slot is compatible with DDR3 but not always on simpler, older motherboards If a motherboard is pushing 1.5 into a 1.35 DDR3L thats bad Some modules of RAM can handle from 1.25 V to 1.65 V
What is Linux system RAM requirements
Depends on what distro is being used Ubuntu requires one similar to MAC and Windows many distros get by on very minimal system requirements
What is error correction code RAM?
Detects and corrects any time a single bit is flipped on the fly (. not double-bit error though) Slower than non ECC RAM Comes in every package type and can lead to some odd sounding numbers DDR2, DDR3, or DDR4 sticks can come in 240 pin, 72 bit versions Also 20-pin 72-bit SO-DIMM format The extra 8 bits beyond 64 bit data stream for the ECC Requires special motherboard
What is latency?
Different RAM responds to electrical signals at varying rates, some take longer. This delay in response is latency
Where can intermittent memory issues be from?
Dying power supply, electrical interference, buggy application, buggy hardware and more Show as lockups, general protection faults, and page faults Never had same address or happen with the same application check power supply first
True or false, you can use RAM faster than motherboard speed
True, but not a lot of point. it's expensive and you won't see improvement.
True or false, a stick of RAM is called a RIMM
True, it literally just rhymed
What is a bank?
Each slot for a DIMM
True or false, commands are only one byte
False, 1 byte is the minimum but complex commands require two or more
True or false, CPU knows location of RAM
False, CPU doesn't where where RAM is or what kind it is, just an address bus. The MCC knows the real location of DRAM
True or false, a Pentium III computer with a 100 MHz frontside bus needs SDRAM DIMMs rated to handle it like PC66 through PC133
False, in this situation, only PC100 or PC133 is acceptable. Must be equal to or greater than bus speed.
True or false, RAM does not make errors
False, it can give bad data to memory controller In certain applications (like Bank servers) errors are not acceptable
True or false, 400 MHz frontside bus speeds were achieved by making the system clock faster
False, it was done by making CPUs and MCCs capable of sending 64 bits of data two or four times for every clock cycle, effectively doubling or quadrupling the system bus speed
True or false, SDRAM runs in any PC
False, the PC must be designed to use SDRAM Systems with slots for 168-pin DIMMS use SDRAM A DIMM in any of these slots could fill the 64 bit bus
What are the steps to upgrading RAM
First, determine if insufficient RAM is the cause of system problems Next, pick proper RAM for the system Use good installation practices Always store RAM in anti-static packaging and use ESD handling procedures as RAM is very sensitive to ESD
What is a dual in line memory module (DIMM)
Form of SDRAM introduced in 1996. Originally came in micro-DIMM or small outline DIM (SO-DIMM). With the exception of 32-bit 72 bit SO-DIMM, all DIMM varieties delivered 64 bit wide data to match 64 bit data bus or every CPUY since the original Pentium
How does Virtual Memory work?
Fully automated process Starts by creating a page file that resides on hard drive ( its like a temporary storage box) only removes running programs temporarily from RAM and into page file if RAM is exceeded Moves least used program into page file programs can't run from page file so when that moved program becomes in use, it's moved back to RAM and it moves another program to page file
What us dynamic random access memory (DRAM)?
Functions like an electronic spreadsheet with numbered rows containing ones or zeros. Each spreadsheet cell is a special type of semiconductor that can hold one bit by using microscopic capacitors and transistors. DRAM makers put these semiconductors into chips that can hold a certain amount if bits. Those bits get organized into rows and columns. Each chip has a limit number of lines of code and width limit. The chips are describes by bits like x8 and x16
How do you determine the optimum capacity of RAM to install and right RAM for motherboard?
Get inside your case and get motherboard manual See how many sticks of RAM are installed and how many slots are open Check motherboard manual or manufacturers website to determine total capacity of RAM system can handle and what specific technology works with that system CPU-2 can do this too
What is a single in-line memory module? (SIMM)
Had 8 DRAM chips. To add RAM to a machine, need the right stick or sticks for that motherboard
What are the specific requirements a PC has for RAM?
Has to give the right specific number of bits Needs RAM that could store data in 8-bit (1 byte) chunks so that each time the CPU asks for a line of code, the memory controller chip (MCC) could put a 8-bit chunk on the data bus
What is hardware addressing?
If you run out of RAM, every computer had the capability to make a portion of your hard drive look like RAM in case you run out of real RAM
Can you mix and match RAM sticks?
It's better to match but it seems you kinda can mix and match at your own peril. All motherboards are capable of handling different capacities of RAM if 3 slots, can put 2 GB in one and 4 GB in other with highest chance of success To ensure max stability, shoot for as close as you can get to uniformity of RAM Chose RAM sticks that match in technology, capacity, speed and latency
What is Rambus DRAM (RDRAM)?
It's faster than SDRAM, developed to hand quad-pumped 400 MHz frontside bus for Pentium 4 by Rambus Inc. It can handle speeds up to 800MHz. Not much support due to development delay and hefty price. Shares almost all qualities of SDRAM
How do you install So-DIMMS in laptops
Laptops used to have to be sent back to be upgraded Access usually requires removing a panel or lifting keyboard Can slide panel off to reveal SO-DIMMs Slide pins into position and snap SO-DIMM down into retaining clips Before doing work, turn it off and disconnect from AC wall socket and remove batteries use antistatic wrist strap because laptops are even more susceptible to ESD
Latency and DDR2,3 and 4
Latency number was a big deal for DDR2 and 3 When DDR4 debuted, those relatively high CL numbers made enthusiasts were afraid it would be slow, resulting in latencies like older DDR3
What is the XMP, extreme memory profile
Later DDR3 model that enables users to overclock their RAM easily and uses higher density memory chips up to 16 GB AMDs version is the AMP, AMD Memory Profile
Troubleshooting RAM
Memory errors include system lock ups, page faults and other errors Indicate bad RAM but often point to something unrelated (especially true with intermittent problems) system lock ups and page faults in Windows can indicate problems with RAM
What is DDR4?
Offers higher density and lower voltages than DDR3 and can handle faster data transfer rates These top out at 64GB but could be made up to 512GB, runs at 1.2v with a performance version that runs at 1.35v and. a low voltage version. at 1.05v The max for DDR3 is 16 These use a 288 pin DIMM and are not backwards compatible with DDR3 slots The SO-DIMMS have 260 pins and are not compatible with DDR3 204 pin SO-DIMM slots Referred to with mega transfers per second (MT/s) instead of bit rate
What is important to note about terminology used to describe consumer RAM
People still use the work "byte" to describe how much DRAM they have even if modern ones come in sizes wider than a byte The common usage describes the total capacity of RAM on a stick in bytes People don't care about width, just that they have enough You need to pick the right RAM for different computers
How do you set up readyboost?
Plug in readyboost approved USB drive or flash device and right click device in computer and select properties click readyboost tab and select radio button next to "Dedicate this device to readyboost" or "Use this device". click apply to enhance system performance
What is virtual memory?
Portion of hard drive as an extension of system RAM OS (all OS's do this) uses part of it's available drive space to save a page file or swap file When running out of RAM, system swaps less uses program from RAM to page file
Options for RAM problems
RAM testing, but expensive replace and pray method, replace each stick with a known good one run software based tester (chance that starting tester can cause an error) Windows Memory Diagnostic tool for Windows 7 and beyond Scans RAM automatically when you encounter a problem MemTest 86+ good for other OS's
What is serial presence detect (SPD)
RAM makes put an SPD chip on all sticks that hold info about the DRAM When PC boots, queries SPD chip so. MCC knows how much RAM, how fast it is and more any program can query an SPD chip rely on SPD chip to set up RAM timings properly for system when it boots If RAM. has bad SPD chip, get a POST error message and system wont boot. you'll have to buy a new stick
What is registered or buffered RAM?
Refers to a small register installed onto some memory modules to act as a buffer between the DIMM and the memory controller Little extra bit of circuity helps compensate for electrical problems that crop up in systems with lots of memory modules in the servers Motherboards either use buffered or unbuffered RAM (typical RAM)
How does SDRAM relate t the system clock?
SDRAM clock speeds match the frontside bus as it is tied to the system clock with 5 common clock speeds early on: 66, 75, 83, 100 and 133 MHz RAM speed has to match or exceed the system speed Speeds are written with "PC" in front (EX: PC133)
What are the 3 types of dynamic random access memory (DRAM)
SDRAM, RDRAM and DDR RAM
How do you turn 1 bit wide DRAM into 8 bits wide like CPU wants?
Take 8 1-bit-wide chips and use the memory controller chip (MCC) to organize them electronically to be 8 wide
what is parity RAM
The first type of error detecting RAM It stored an extra bit of data that the MCC used to verify whether the data was correct However, if MCC found the error, it couldn't correct it
How do I know if I need more RAM?
The system is sluggish and excessive hard drive addressing If programs take forever to load and running programs seems to stall and run slowly This can happen as machines get older and software gets beefier
True or false, DDRs are not the same as GDRx, GDRx is for video cards
True
True or false, as CPUs and MCCs have gotten wider and faster, DRAM manufacturers have invented new DRAM technologies that delivery enough data at a single pop to optimize the flow of data in and out of the CPU
True
True or false, if you put a high-latency stick in a low latency motherboard, you'll get an unstable or dead PC
True
True or false, laptops use 72 pin SO-DIMM and needs to install 2 sticks for a full bank as each stick only provides half the bus length
True
True or false, some DDRs motherboards support triple channel or quad channel architecture
True
True or false, the default recommended page file size in Windows is 1.5 times the amount of RAM installed on your computer
True
True or false, variations in packaging, speed, quality and capability to handle data with more and with fewer errors
True
True or false, CL17 is slightly faster than CL19
True CL refers to clock cycle delays, relative to the clock. speed of RAM 17 means the memory delays 17 clock cycles before requesting data 19 means it delays 19
True or false, the PC industry adopted DDR SDRAM as standard system RAM
True, Intel doesn't make the stuff that required RDRAM
True or false, modern machines use language that has some commands that are one up to 64 bits, 8 bytes wide and a frontside bus that can handle more than 8 bits
True, to optimize data flow to/from the CPU, modern MCC provides at least 64 bits of data every time the CPU requests information from RAM
What is the best way to improve overall computer performance with one upgrade?
Upgrade RAM, improves overall system performance, processing speed and stability if you get it right If you do it wrong, you can cause drastic system instability
What is synchronous DRAM (SDRAM)
Used by most modern systems, synchronous DRAM is tied to the system clock like the CPU or MCC so MCC knows when data is ready to be grabbed from SDRAM
What is dual-channel architecture?
Using two sticks of RDRAM together to increase throughput Manufacturers have releases motherboards with MCCs that support dual-channel; architecture using DDR SDRAM Dual-channel DDR motherboards use regular DDR sticks Note, manufacturers often sell RAM in matched pairs, branding them as dual-channel RAM. they require two identical sticks of DDR and must snap into two paired slots
What is a general protection fault (GPF)
an error that can cause an application to crash, often caused by programs stepping on each-other's toes
What is readyboost
enables you to use flash media devices as super-fast, dedicated virtual memory as spinning hard drives are much slower Performance gain can be significant because read/write access on flash memory blows away that of hard drives Not super helpful on systems running SSD, adding more RAM is the better solution
What us double-sided DIMMs?
for either 2 single sided RAM sticks or 1 double sided RAM stick. A double sides stick is like two soldered together. Only supported on certain motherboards and only so much
SO-DIMM
small outline dual inline memory module. Can be spelled as SO-DIMM, SODIMM or SoDIMM