Memory
What is registered memory
(buffered memory) implements extra chip in the center of the module to act as a buffer, stabilizes the system (extremely expensive) Must be supported by the motherboard, improves stability on systems with a lot of RAM (over 1 GB) but might slow system performance
What is memory form factor?
(or packages), with the form factor determining the number of pins and the size of the memory module. (SIMM's, DIMM's, SO-DIMM's and RIMM's)
DDR2 SD RAM
Double Data Rate 2 (twice as much as DDR/ 4 times SDRAM) and accepts 4 data sets. Buffer between data bus and memory 1.8 Volts and operates between 200-533 Megahertz he internal memory frequency is half that of the bus frequency (100-266 MHz)
What is an SBD chip?
Serial Prescience Detect-Allows BIOS to auto configure to the memory for operation
What is SIM in relation to memory?
Single In-line Memory (before DDR2-3)
What is SO-DIM in relation to memory
Small Outline Double Memory Module-Laptops and typically half the size
What is the maximum a 32 bit motherboard can handle?
4GB of memory MAX (can use PAE to access more for 32 windows servers running same type of OS)
What is a Word in significance to RAM
64 bits of data
What is DDR 3 SD RAM
8 data sets per clock cycle Has a buffer between data bus and memory 1.5 Volts and operates between 400-1000, the internal memory frequency is one-fourth that of the bus frequency (100-250 MHz
What is the Bandwidth?
Amount of data that can be sent
What does Timing measure in Memory
CL:CAS Latency tRCD: Row Address to Column Address Delay tRP: Row Precharge Time tRAS: Row Active Time LOWER, TIME THE BETTER FOR ALL
What does the frequency discuss
Clock cycle speeds- Bus (always a multiple of the internal frequency-Ex 1000) Internal (always a multiple of the bus frequency-Ex 200)
What is CAS Latency?
Column Address Strobe latency- handles delay (lower latency the better) typically measured in clock cycles
What is the DDR standard for identifying memory?
DDR designation is doubt the bus speed (typically the higher equals bandwidth with lower being frequency-divide by 8 bandwidth to get frequency)
Dual channel memory supports what type of memory?
DDR2 OR DDR3 (Dual-channel systems theoretically double the bandwidth. However, in practice, only a 5-15% increase is gained)
Triple Channel memory supports what type of RAM
DDR3
Assuming the same operating frequency what are the advantages of DDR3 over DDR2?
DDR3 uses less power than DDR2 DDR3 doubles the data transfer rate of DDR2
What type of RAM is used in personal computes?
DRAM
What are the two types of RAM?
DRAM SRAM
How do you get PC frequency from a bandwidth question?
Divide by 16
What is DDR SDRAM
Double Data Rate SD RAM 1 command per clock cycle followed by 2 data sets(double the data within the same time period) 2.5 volts and operates frequencies between 100-200 Megaherts
What is DIM in relation to memory?
Double In-line Memory any variation of DDR RAM
What is DRAM?
Dynamic Random Access Memory Stores each bit of data on a capacitor or transistor which must be consistently refreshed. Is used in the main system memory on a computer. High Density/Simple/Inexpensive
What do we consider when selecting memory
ECC Memory, Speed, column address strobe latency, Timing
What is ECC?
Error Correcting Code- detects data corruption (typically servers) extra chip added to memory module
After installing two memory modules, you power on the system to check for errors, the BIOS only recognizes one of the memory modules, what should you check first?
Make sure that both modules are seated properly in their slots.
A customer needs to use several applications. Currently, the computer cannot keep all the necessary applications open at the same time. What should you upgrade?
Memory
How can you verify the memory on the motherboard?
Motherboard/System Documentation Memory Configurator/Scanner (online)
How can you check your motherboard and memory on a windows 7 computer that is running w/o internet?
My computer, properties of C drive and your windows experience.
What is the PC- standard
PC- older specs identified frequency or bandwidth, high numbers typically bandwidth New standard
What is the name for the routine that test the motherboard, memory, disk controllers, video, keyboard and other system hardware?
POST-Power On Self-Test
Which is the fastest of all storage types?
RAM
What is single/double-sided RAM
RAM has memory modules that are organized into a single logical bank; double-sided RAM has modules organized into two banks. The computer can only access data in one bank at a time. Therefore, single-sided RAM allows access to all of the memory, while with double-sided RAM, the computer must switch between banks
What are the two types of RAM with two notches?
RDRAM and RAMBUS DRAM-has two slots in the middle (typically with heat spreader SDRAM has two slots that are far apart
RIMM
Rambus Inline Memory Modules (older model, only in use with Rambus)
RD RAM
Rambus Ram, first to double DDR standard 32 bits with two data sets Any open modules have to continuity slots installed
What is RAM?
Random Access Memory-nonpresistant Computer can access any point on RAM without going forward/backward on a disk
What is SRAM?
Static Random Access Memory Stored using switches that don't need to be refreshed (more expensive) but retains as long as there is power, typically CPU Cache More Complex/expensive/Less Dense
SD RAM
Synchronous Dynamic RAM, also know as Single Data Rate-Frequency of the memory is synchronized with the frequency of the system clock. Can read or write 64-bits at a time, matching width of system bus. A 64-bit word is stored across 8 DRAM chips, with each chip receiving 8-bits of data. 3.3 volts between 33-166 Megahertz
Where is the Memory controller bus on newer and older systems?
The memory controller is in the Northbridge chip on the motherboard. Newer processors move the memory controller onto the processor chip, allowing the processor to communicate with RAM without going through the front-side bus.
What are the four factors that limit the memory you can install?
The number of memory slots on the motherboard, the capacity, module capacity and the maximum amount of memory that can be addressed.
CAS Latency is what and which of the four timing numbers?
The time between a read request and the return of that data The first number (lower the better for same comparisons)
What is the maximum a 64 bit motherboard can handle?
Theoretical 16 ETB, practically 1-2 TB
Memory that has EC can be seen by sight, how?
They have an additional module, or odd number of modules on the memory
For DDR, DDR2 and DDR3 what does the number afterwards stand for
Twice the bus speed, signifying double the data in a single clock cycle.
If you install memory of a faster frequency with slower frequency what will happen?
When you mix memory settings with different speed ratings all memory will operate at the slowest rate.
Can we identify memory by pin density?
Yes, DDR has 184, BUT DDR-2 has 240 as well as with DDR-3 (however notches will be different (DDR middle, DDR-2 Right and DDR-3 Left)
What is Parity in regards to error correction?
a 1 or a 0 is appended to each byte so that the total number of 1s is always either even or odd. Parity methods can detect errors in only one bit, but cannot fix them because they cannot determine the specific bit with the error. The parity error checking method is older and has almost been completely eclipsed by the new ECC method
What is a website with a memory scanner if the computer has access to the Internet
www.crucial.com Download the System Scanner tool