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When a datum is written to the cache, it must at some point be written to the backing store as well. The timing of this write is controlled by what is known as the write policy. In a write-through cache, every write to the cache causes a write to the backing store. Alternatively, in a write-back cache, writes are not immediately mirrored to the store. Instead, the cache tracks which of its locations have been written over (these locations are marked dirty). The data in these locations is written back to the backing store when those data are evicted from the cache. For this reason, a miss in a write-back cache will often require two memory accesses to service: one to retrieve the needed datum, and one to write replaced data from the cache to the store.
The preceding information was obtained from the related link at the left.
- Write Back - Data is written first to the cache, then to the logical drive for better performance. The Promise VTrak has a cache backup battery to protect data in the cache from a sudden power failure.
- Write Thru - Also written as "Write Through". Data is written to the cache and the logical drive at the same time for safer operation. No battery backup is needed since data is written to the drives immediately.
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How do cache memory improve the system performance?
Caches are meant to improve memory access performance of the computer system. There are hardware caches implemented as well software caching is also done in Operating system to improve performance.
How do you use CPU memory as RAM is there any software for that?
The L1 and L2 caches (the "CPU memory") are already being used in a manner similar to RAM. L1 and L2 cache acts as a sort of buffer, so that the CPU does not have to fetch data from main memory as often, which slows the computer down. This, the fact that the circuitry to use the caches as main memory isn't available on most motherboards, and the fact that CPU caches are simply not large enough to run a modern operating system, make this both impossible and impractical.
What is cache coherence and why is it necessary?
Cache coherence is a property of two or more caches mirroring the same shared resource. If all caches agree about the cached content, the caches are coherent. If (at least) one cache is changed the caches are incoherent until the changes are propagated to the other caches.Multiprocessing systems are the context where one will most likley come across the concept of cache coherence. In a shared memory multiprocessor, each processor has its own memory cache, so any change must be mirrored by all other caches, so that all processors see the same memory content. Should a processor happen to use an outdated value, the results are unpredictable. Or, if you like it better, the results are very predictably garbage.
The memory in the processor package but not on the processor die is called?
L3 CacheThere is no specific name for memory caches based on physical location. CPU memory caches are named for function, not location.As such, there are Level 1, Level 2, and Level 3 caches (and, theoretically, there's nothing preventing Levels 4 and up from being created). Each can be located anywhere (on-die, in-package, off-chip, etc.) depending on the design of the CPU and motherboard.Modern x86 chips from Intel and AMD include up to L3 cache on-die.
You cant find Cache on options?
Please ellaborate. Which cache are you looking for? Modern computers can have over a dozen different caches L1 and L2 CPU Caches Harddrives Caches Browser Caches DLL Caches DNS Caches etc.
What kind of memory is temporary and holds the image on the monitor?
There are several kinds of temporary memory, depending on what program and platform you're using. Scratch disks, clipboards, caches, even layers in Photoshop can be considered temporary memory.
What is the name of the memory cache that is on the same die as the processor?
Level 1 cache (L1 cache)There is no specific name for memory caches based on physical location. CPU memory caches are named for function, not location.As such, there are Level 1, Level 2, and Level 3 caches (and, theoretically, there's nothing preventing Levels 4 and up from being created). Each can be located anywhere (on-die, in-package, off-chip, etc.) depending on the design of the CPU and motherboard.Modern x86 chips from Intel and AMD include up to L3 cache on-die.
What is the name of the memory cache that is closest to the processor die but is not housed on the die?
Level 2 cache (L2 cache).There is no specific name for memory caches based on physical location. CPU memory caches are named for function, not location.As such, there are Level 1, Level 2, and Level 3 caches (and, theoretically, there's nothing preventing Levels 4 and up from being created). Each can be located anywhere (on-die, in-package, off-chip, etc.) depending on the design of the CPU and motherboard.Modern x86 chips from Intel and AMD include up to L3 cache on-die.
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.
Give two reasons why caches are useful?
It minimizes the miss match between the main memory and the processor Actually, there is one reason for a cache to exist: speed. A cache exists to speed up the time that the processor takes to obtain a bit of data. Typically, main memory is many times slower than the processor - in modern computers, it can be 1000 times slower. So, caches are made up of memory more expensive and faster than main memory, to store parts of main memory in, in the hopes that the data the processor wants will be available in the cache.
What are the two types of cache memory?
There are different type of cache memory: processor cache memory, cache memory ram,1 cache memory l2, cache memory, CPU cache memory, disk cache memory, hard disk cache, cache memory motherboard.
Do all caches need a replacement policy?
not all caches need a replacement policy.
