Does some CPUs now have three levels of cache memory?

What cache typically has the most memory?

Caches are generally defined as L1, L2, and L3. If a CPU has any cache memory at all, it will have at least L1 cache. L1 cache is the fastest, and most expensive, type of cache memory. Usually CPUs will only have a very small amount of L1. L2 is typically larger, less expensive, and slower than L1. L3 is less expensive, larger, and slower than L1 or L2, if present. All three levels of cache memory are magnitudes faster than system memory. Systems withequivalenthardware, including CPUs will identical speeds, will perform better at certain tasks when more cache memory is present, with L1 cache adding the most performance boost.

What is the function of CPU cache?

Many CPUs have what is known as a CPU cache. The function of this CPU cache is to speed up access to data.

What are three factors you need to consider when selecting a new processor?

some factors that you need to consider.first the purpose you need that cpu.the cpus clock,the cpus fsb,the cpus socket to be compatible with your motherboard and the cpus l2 cache

Is cache on a CPU?

CPUs do have a cache (either L1, L2 or L3), but cache is not exclusively on the CPU.

What is meant by cache memory?

In a computer, cache memory is a special type of fast access memory that is between the CPU and the main memory. If the CPU always had to access main memory, it would spend most of its time idle waiting for that memory to respond. But because memory accesses statistically tend to cluster around each other in real programs instead of completely randomly scattering across memory, a single CPU memory access can cause the cache memory controller to perform a fast burst access of main memory including that address to load an entire "line" of cache memory. If a following CPU memory access is in this same "line" of cache memory that has already been loaded, it will not have to wait for the main memory to respond, instead the cache responds first providing the copy it has of that address' contents.Cache memory was originally invented in the late 1950s by IBM for their 7030 Stretch supercomputer (a machine built entirely using discrete germanium transistors, no integrated circuits at all). However all the 7030 documents use the term "virtual memory" for what is now universally called cache memory, and "virtual memory" means something entirely different now.Each cache memory unit is composed of three sections:cache controllercontent addressable memory (CAM)fast access static random access memory (SRAM)The cache controller section contains all the logic circuits that coordinate the operation between the CPU(s), cache, and main memory. The CAM is a special type of memory used to store the memory address of each active cache "line" along with some status bits that is addressed by it contents (not an address number as in ordinary RAM and ROM). The SRAM contains the copies of address contents previously read from main memory, and is addressed through the CAM. Cache memory is organized into levels (L1, L2, L3, etc.) with the L1 Cache closest to the CPU and each additional level further away until the final Cache level connects directly to the memory. The L1 Cache uses the fastest speed SRAM but has the smallest amount of SRAM and each additional level uses slower speed SRAM but has more SRAM than the previous level. The L1 Cache is usually divided into two independent Caches (L1 Instruction Cache and L1 Data Cache) and is dedicated to supporting only one CPU but each additional level is usually a single Cache (shared by both instructions and data) and in systems having multiple CPUs may be shared by two or more CPUs. In systems having multiple CPUs the cache controllers must implement special bus protocols to coordinate line invalidations and updates to prevent some of the CPUs from accessing obsolete Cache contents from its Caches when a different CPU that does not use those Caches has modified memory that is mapped to both its local Caches and the other CPUs local caches.Proper design of a Cache memory system for a computer requires extensive simulation of typical real code expected to be used on the system. Any problems found must be corrected, so that the Cache usage will remain even and balanced, and anticipated performance verified.

What is temporary storage on chips called?

Temporary storage on chips is called memory. Most such solid-state memory is in the form of random-access memory (RAM) chips, usually dynamic RAM (DRAM). The people who write operating systems and the computer architects that design computer systems and CPUs often use many different temporary storage areas, each one with a different name. If you are building a high-speed computer or writing a high-performance operating system, you will learn about the temporary storage areas known as the disk page cache, the stack, the heap, and the virtual memory page table, are (more or less) stored in the main memory DRAM. The CPU has a few temporary locations called registers. Often there is one or more levels of cache (the L1 cache, the L2 cache, etc.) between the CPU and the main memory. High-performance CPUs typically put a cache on the same chip as the CPU; some older personal computers had an "external cache" SRAM chips between the CPU chip and the main memory DRAM chips. Many high-performance computers have several levels of successively larger and slower caches -- an extremely fast I-cache and D-cache and TLB, the L1 cache, the L2 cache, the L3 cache, and main memory.

What cache memory is designed inside the CPU?

L1 and L2; Many years ago L1 was the only cache memory integrated into the CPU (processor) and L2 had to be added to the motherboard. Currently (as of year 2013), CPUs implement both L1 and L2 cache in the casing of the processor. Thus, processors (CPUs) ship with amounts of L2 cache independent for each processor core.

What is write once with respect to cache?

When clients in a system maintain caches of a common memory resource, problems may arise with inconsistent data. This is particularly true of CPUs in a multiprocessingsystem. Referring to the "Multiple Caches of Shared Resource" figure, if the top client has a copy of a memory block from a previous read and the bottom client changes that memory block, the top client could be left with an invalid cache of memory without any notification of the change. Cache coherence is intended to manage such conflicts and maintain consistency between cache and memory.

What three things do cpu's make up?

CPUs consist of three main components: the arithmetic logic unit (ALU) for performing mathematical operations, the control unit for managing instruction execution, and the cache memory for storing frequently used data for faster access.

What type of memory stores frequently used instructions or data needed by the CPU?

the memory that directly communicates with the CPU is called Cache Memory this is; When the processor(CPU) needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, which is much faster than reading from or writing to main memory. A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations. As long as most memory accesses are cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory. [by Deogratius Ambrose IAA-Tanzania] the memory that directly communicates with the CPU is called Cache Memorythis is; When the processor(CPU) needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, which is much faster than reading from or writing to main memory. A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations. As long as most memory accesses are cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory. [by Deogratius Ambrose IAA-Tanzania]

What is memory sharing?

In computer hardware, shared memory refers to a (typically) large block of random access memory that can be accessed by several different central processing units (CPUs) in a multiple-processor computer system. The issue with shared memory systems is that the many CPUs need fast access to memory and will likely cache memory. Whenever one cache is updated with information that may be used by other processors, the change needs to be reflected to the other processors, otherwise the different processors will be working with incoherent data (see cache coherence and memory coherence). Such coherence protocols can when they work well provide extremely high performance access to shared information between multiple processors. On the other hand they can sometimes become overloaded and become a bottleneck to performance. The alternatives to shared memory are distributed memory and distributed shared memory, with another, similar set of issues. See also Non-Uniform Memory Access. In software the term shared memory refers to memory that is accessible by more than one process, where a process is a running instance of a program. In this context, shared memory is used to facilitate inter-process communication.

What is memory space in microprocessor?

memory space in microprocessor means cache ,it is the part of the microprocessor which contains the memory to store instructions which are used to perform different functions by the processor. where cache1 is referred to memory in microprocessor and cache2 is placed on motherboard which also contains memory to store instructions. Memory space can also mean the total size of virtual memory that a CPU can address, and the layout (flat or segmented) of this space. Most modern CPUs found in PCs (AMD and Intel x86_64 chips) are 64-bit CPUs, but, due to cost and practical use considerations, limit their virtual memory space to be 48-bits (or less).