Computer Architecture RAM/Memory quiz

What is RAM?

"Random Access Memory"

What are the differences between DDR 1,2,3, and 4?

-DDR accepts one command per clock cycle, followed by two data sets. So, for each clock cycle the DDR RAM can accept two 64 bit words of data. DDR operates at two and a half volts at bus frequencies between 100 and 200 megaherts (MHz). -DDR2 doubles the bandwidth of DDR. It accepts four data sets per clock cycle. It operates at 1.8 volts, with a frequency of 200 to 533 MHz, making the frequency faster and doubling the amount of data submitted in a single clock cycle. DDR2 has the addition of a buffer between the data bus and the memory. The buffer allows movement of the four data sets, and the increased speed per clock cycle. -DDR3 doubles the data rate of DDR2, allowing it to accept eight data sets per clock cycle. DDR3 also has a buffer and operates at 1.5 volts with a frequency between 400 and 1,000 MHz. -DDR4 is the latest type of RAM. DDR4 has an added power down mode to reduce power consumption when the system is in standby. The lower operating voltage and power enhancements allow DDR4 RAM to draw less power, and run cooler than DDR3 RAM. DDR4 operates at 1.2 volts. DDR4 chips are manufactured in densities of up to 2 to 16 gigabytes per chip, which is double the density of DDR3. Going from DDR to DDR4, the voltage is lowered while also increasing the operating frequency. The amount of data submitted in each clock cycle is also doubled with each upgrade.

What is DIMM?

A DIMM (dual in-line memory module) has pins on both sides of the module, with each pin being unique. -DIMMs have 64-bit data path that matches the system bus width. -RDRAM and DDR/2/3/4 are packaged into DIMMs, with each specification having a unique number of pins and notch position. -DDR4 allows for DIMMs of up to 512 GB in capacity.

What is SODIMM?

A SODIMM (small outline dual in-line memory module) is a smaller DIMM used in laptops. -SODIMMs are much smaller than other memory, perfect for notebook computers. -Notice the notch slightly off center in the 144-pin SODIMM. 144=pin SODIMMs are used by SDRAM, DDR, and DDR2 memory. -On the 200-pin SODIMM, notice that the notch is farther off center than the 144-pin SODIMM. You might also be able to notice the high pin density. 200-pin SODIMMs are used by DDR2 and DDR3 memory.

What are the differences between DRAM and SRAM?

DRAM - Refreshes thousands of times per second; 60 nanoseconds; Less expensive; Volatile SRAM - Needs no refresh; 10 nanoseconds; More expensive; Volatile and Non-volatile

What is DRAM?

DRAM stores data using a single transistor for every bit of data (a 0 or a 1). To maintain the state of the transistor, DRAM must continuously supply power to the transistor. When the power is turned off, the data is lost.

What is SRAM?

SRAM stores data using four transistors for every bit of data. SRAM does not require constant power to maintain the contents of memory.

What does the IMC do?

The address of each memory cell is a number selected by the integrated memory controller or IMC, for a byte of data. An IMC is a digital circuit that manages the flow of data going to and from the RAM. This address is used to write and retrieve data. The IMC keeps track of the addresses of all the cells, where they're at, and what's in them.

What is UniDIMM?

UniDIMM (Universal DIMM) is a specification for DIMMs and is designed to carry DRAM chips. -UniDIMMs can be populated with either DDR3 or DDR4 chips, but do not support any additional memory control logic. Because of this, the computer's memory controller must support both DDR3 and DDR4 memory standards. UniDIMM: -is an upgrade to the current SODIMM standard. -allows mobile platform users to use both DDR3 and DDR4.