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Memory Access Time
Column address strobe latency, also called CAS latency or CL, is the delay in clock cycles between the READ command and the moment data is available. In asynchronous Dynamic random-access memory, DRAM, the interval is specified in nanoseconds (absolute time). In synchronous dynamic random-access memory, synchronous DRAM, the interval is specified in clock cycles. Because the latency is dependent upon a number of clock ticks instead of absolute time, the actual time for an SDRAM module to respond to a CAS event might vary between uses of the same module if the clock rate differs. RAM operation background Dynamic RAM is arranged in a rectangular array. Each row is selected by a horizontal ''word line''. Sending a logical high signal along a given row enables the MOSFETs present in that row, connecting each storage capacitor to its corresponding vertical ''bit line''. Each bit line is connected to a ''sense amplifier'' that amplifies the small voltage change produced by the stora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Random-access Memory
Dynamics (from Greek language, Greek δυναμικός ''dynamikos'' "powerful", from δύναμις ''dynamis'' "power (other), power") or dynamic may refer to: Physics and engineering * Dynamics (mechanics), the study of forces and their effect on motion Brands and enterprises * Dynamic (record label), an Italian record label in Genoa Mathematics * Dynamical system, a concept describing a point's time dependency ** Topological dynamics, the study of dynamical systems from the viewpoint of general topology * Symbolic dynamics, a method to model dynamical systems Social science * Group dynamics, the study of social group processes especially * Population dynamics, in life sciences, the changes in the composition of a population * Psychodynamics, the study of psychological forces driving human behavior * Social dynamics, the ability of a society to react to changes * Spiral Dynamics, a social development theory Other uses * Dynamics (music), the softness or loudn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DRAM
Dram, DRAM, or drams may refer to: Technology and engineering * Dram (unit), a unit of mass and volume, and an informal name for a small amount of liquor, especially whisky or whiskey * Dynamic random-access memory, a type of electronic semiconductor memory * Dram, Welsh term for a minecart, a small railway cargo truck used in a mine railway Currency and geography * Dram, Armenian for "money" ** Armenian dram, a monetary unit ** Artsakh dram (formerly ''Nagorno-Karabakh dram''), a monetary unit * Dram, the Tibetan name for the town of Zhangmu on the Nepal-Tibet border * Historic English name for Drammen, Norway Music * DRAM (musician) (Shelley Marshaun Massenburg-Smith, born 1988), American rapper and actor * Database of Recorded American Music, an online resource * The Drams, an American band made up of members of Slobberbone See also * Dram shop, a bar, tavern or similar commercial establishment where alcoholic beverages are sold * Dirham The dirham, dirhem or drah ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR5 SDRAM
Double Data Rate 5 Synchronous Dynamic Random-Access Memory (DDR5 SDRAM) is a type of synchronous dynamic random-access memory. Compared to its predecessor DDR4 SDRAM, DDR5 was planned to reduce power consumption, while doubling bandwidth. The standard, originally targeted for 2018, was released on July 14, 2020. A new feature called Decision Feedback Equalization (DFE) enables input/output (I/O) speed scalability for higher bandwidth and performance improvement. DDR5 has about the same latency as DDR4 and DDR3. DDR5 octuples the maximum DIMM capacity from 64 GB to 512 GB. DDR5 also has higher frequencies than DDR4, up to 9600 MT/s is currently possible, 8200 MT/s translates into around 66 GB/s of bandwidth. Using liquid nitrogen 13000 MT/s speeds were achieved. Rambus announced a working DDR5 dual in-line memory module (DIMM) in September 2017. On November 15, 2018, SK Hynix announced completion of its first DDR5 RAM chip; running at 5.2 GT/s at 1.1 V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR4 SDRAM
Double Data Rate 4 Synchronous Dynamic Random-Access Memory (DDR4 SDRAM) is a type of synchronous dynamic random-access memory with a high bandwidth (" double data rate") interface. Released to the market in 2014, it is a variant of dynamic random-access memory (DRAM), some of which have been in use since the early 1970s, and a higher-speed successor to the DDR2 and DDR3 technologies. DDR4 is not compatible with any earlier type of random-access memory (RAM) due to different signaling voltage and physical interface, besides other factors. DDR4 SDRAM was released to the public market in Q2 2014, focusing on ECC memory, while the non-ECC DDR4 modules became available in Q3 2014, accompanying the launch of Haswell-E processors that require DDR4 memory. Features The primary advantages of DDR4 over its predecessor, DDR3, include higher module density and lower voltage requirements, coupled with higher data rate transfer speeds. The DDR4 standard allows for DIMMs of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR3 SDRAM
Double Data Rate 3 Synchronous Dynamic Random-Access Memory (DDR3 SDRAM) is a type of synchronous dynamic random-access memory (SDRAM) with a high bandwidth (" double data rate") interface, and has been in use since 2007. It is the higher-speed successor to DDR and DDR2 and predecessor to DDR4 synchronous dynamic random-access memory (SDRAM) chips. DDR3 SDRAM is neither forward nor backward compatible with any earlier type of random-access memory (RAM) because of different signaling voltages, timings, and other factors. DDR3 is a DRAM interface specification. The actual DRAM arrays that store the data are similar to earlier types, with similar performance. The primary benefit of DDR3 SDRAM over its immediate predecessor DDR2 SDRAM, is its ability to transfer data at twice the rate (eight times the speed of its internal memory arrays), enabling higher bandwidth or peak data rates. The DDR3 standard permits DRAM chip capacities of up to 8 gigabits (Gbit) (so 1 gigabyte by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR2 SDRAM
Double Data Rate 2 Synchronous Dynamic Random-Access Memory (DDR2 SDRAM) is a double data rate (DDR) synchronous dynamic random-access memory (SDRAM) interface. It is a JEDEC standard (JESD79-2); first published in September 2003. DDR2 succeeded the original DDR SDRAM specification, and was itself succeeded by DDR3 SDRAM in 2007. DDR2 DIMMs are neither forward compatible with DDR3 nor backward compatible with DDR. In addition to double pumping the data bus as in DDR SDRAM (transferring data on the rising and falling edges of the bus clock signal), DDR2 allows higher bus speed and requires lower power by running the internal clock at half the speed of the data bus. The two factors combine to produce a total of four data transfers per internal clock cycle. Since the DDR2 internal clock runs at half the DDR external clock rate, DDR2 memory operating at the same external data bus clock rate as DDR results in DDR2 being able to provide the same bandwidth but with better la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR SDRAM
Double Data Rate Synchronous Dynamic Random-Access Memory (DDR SDRAM) is a double data rate (DDR) synchronous dynamic random-access memory (SDRAM) class of memory integrated circuits used in computers. DDR SDRAM, also retroactively called DDR1 SDRAM, has been superseded by DDR2 SDRAM, DDR3 SDRAM, DDR4 SDRAM and DDR5 SDRAM. None of its successors are forward or backward compatible with DDR1 SDRAM, meaning DDR2, DDR3, DDR4 and DDR5 memory modules will not work on DDR1-equipped motherboards, and vice versa. Compared to single data rate ( SDR) SDRAM, the DDR SDRAM interface makes higher transfer rates possible through more strict control of the timing of the electrical data and clock signals. Implementations often have to use schemes such as phase-locked loops and self-calibration to reach the required timing accuracy. The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to double data bus bandwidth without a cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megatransfer
In computer technology, transfers per second and its more common secondary terms gigatransfers per second (abbreviated as GT/s) and megatransfers per second (MT/s) are informal language that refer to the number of operations transferring data that occur in each second in some given data-transfer channel. It is also known as sample rate, i.e. the number of data samples captured per second, each sample normally occurring at the clock edge. The terms are neutral with respect to the method of physically accomplishing each such data-transfer operation; nevertheless, they are most commonly used in the context of transmission of digital data. is 106 or one million transfers per second; similarly, means 109, or equivalently in the US/ short scale, one billion transfers per second. Units These terms alone do not specify the bit rate at which binary data is being transferred because they do not specify the number of bits transferred in each transfer operation (known as the channel wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cache Line
A CPU cache is a hardware cache used by the central processing unit (CPU) of a computer to reduce the average cost (time or energy) to access data from the main memory. A cache is a smaller, faster memory, located closer to a processor core, which stores copies of the data from frequently used main memory locations. Most CPUs have a hierarchy of multiple cache levels (L1, L2, often L3, and rarely even L4), with different instruction-specific and data-specific caches at level 1. The cache memory is typically implemented with static random-access memory (SRAM), in modern CPUs by far the largest part of them by chip area, but SRAM is not always used for all levels (of I- or D-cache), or even any level, sometimes some latter or all levels are implemented with eDRAM. Other types of caches exist (that are not counted towards the "cache size" of the most important caches mentioned above), such as the translation lookaside buffer (TLB) which is part of the memory management unit (MMU) wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Data Rate
In computing, double data rate (DDR) describes a computer bus that transfers data on both the rising and falling edges of the clock signal and hence doubles the memory bandwidth by transferring data twice per clock cycle. This is also known as double pumped, dual-pumped, and double transition. The term toggle mode is used in the context of NAND flash memory. Overview The simplest way to design a clocked electronic circuit is to make it perform one transfer per full cycle (rise and fall) of a clock signal. This, however, requires that the clock signal changes twice per transfer, while the data lines change at most once per transfer. When operating at a high bandwidth, signal integrity limitations constrain the clock frequency. By using both edges of the clock, the data signals operate with the same limiting frequency, thereby doubling the data transmission rate. This technique has been used for microprocessor front-side busses, Ultra-3 SCSI, expansion buses ( AGP, PCI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underclocked
Underclocking, also known as downclocking, is modifying a computer or electronic circuit's timing settings to run at a lower clock rate than is specified. Underclocking is used to reduce a computer's power consumption, increase battery life, reduce heat emission, and it may also increase the system's stability, lifespan/reliability and compatibility. Underclocking may be implemented by the factory, but many computers and components may be underclocked by the end user. Underclocking is the opposite of overclocking. Types CPU underclocking For microprocessors, the purpose is generally to decrease the need for heat dissipation devices or decrease the electrical power consumption. This can provide increased system stability in high-heat environments, or can allow a system to run with a lower airflow (and therefore quieter) cooling fan or without one at all. For example, a Pentium 4 processor normally clocked at 3.4 GHz can be "underclocked" to 2 GHz and can then be safe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locality Of Reference
In computer science, locality of reference, also known as the principle of locality, is the tendency of a processor to access the same set of memory locations repetitively over a short period of time. There are two basic types of reference locality temporal and spatial locality. Temporal locality refers to the reuse of specific data and/or resources within a relatively small time duration. Spatial locality (also termed ''data locality'')"NIST Big Data Interoperability Framework: Volume 1"urn:doi:10.6028/NIST.SP.1500-1r2 refers to the use of data elements within relatively close storage locations. Sequential locality, a special case of spatial locality, occurs when data elements are arranged and accessed linearly, such as traversing the elements in a one-dimensional Array data structure, array. Locality is a type of predictability, predictable behavior that occurs in computer systems. Systems which exhibit strong ''locality of reference'' are good candidates for performance optimiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
