Input / Output Types ROM - RAM - Cache and Virtual Memory
Rom or Conventional (Read Only Memory)
is a read-only memory is completely unchanged without this memory the machine would not start.
Main memory is the standard that goes from 0 to 640 kb. When booting the machine begins to work hard and perform a test, for which you need memory, this is the conventional memory (ROM) and is within the mother (in the bios). Just started using 300 kb, is tested and reaches more than 540 kb or less where it is planted. As they began to have more soft memory requirement showed the call was expanded memory of 640 kb to 1024 kb. Once used all conventional memory used that uses the expanded RAM. As time passes the 1024 kb were scarce and I think the extended memory ranging from 1024 kb to infinity is pure RAM.
memory values \u200b\u200bcan be tracked through the setup of the machine.
RAM or Random Access Memory and (Random Access Memory)
This memory is like a desk as the desks have drawers in which order the information, the bigger the desk (ground plane ) I'll have more boxes in such a way that the micro will spend less time searching and ordering information
The importance of this memory is so large that if the PC is absent NOT START,
acts as if it is still no sound or cursor on the screen or lights that are powered off.
Good for:
Store instructions to run the micro at all times
This is the physical place where the processor must work when opening a program, your instructions are automatically copied in memory, and when we close the program everything is erased (volatilized)
The Ram is like a blackboard where data is copied
also copy the work we are doing in this program
In the Ram copy programs that coordinate the functioning of the PC:
The first part of the Ram is reserved for storing instructions for electronic devices. In this place you can not save anything because it uses the system to know how to handle the devices.
or Memory Sockets Memory Banks
Simm 30 Pin 72 Pin Simm
Dimm Up to 168 Pines
Banks may be three or four and have a mark on the mother where to place the first report. Obviously if the first we have a 64 Mg and the other in the second we say we have 128 mg. The computer works better with one of 128Mg. This is just to the DIMM, the SIMMs are installed in pairs
Memory is like a comb with soldiers chip surface and depends on the number of teeth and the bank to which it is connected, the name which is called:
Simm: Single In line Memory Module Dimm
: Double Memory Module
Rimm, Rambus in-line Memory Module
Ram Evaluation of
works as follows : accessing data in a random Ram or directly from the location where you are without having to walk past other positions eg If I have to remember store where the coffee is in the kitchen, I have no need to remember everything I did during the day to get coffee.
The Ram does not need to scroll covers an entire data stream to come up with one specifically, it looks just where it belongs in this regard is much faster than the ROM.
Storage capacity
Speed \u200b\u200b
data handling capability
different technologies
The storage capacity is measured in megabytes, a byte saved a megabayte letter may save a few million more Mb letters have better memory. Eye
micro goes better with low speed and lots of memory than one with high and low memory. The minimum amount of memory for Windows 98 is 32 Mb
Speed: The speed is measured in Mhz Ram, formerly half
Nanos (one millionth of a second) from 1995, reports began to work at the pace of the mother and began to measure speed in Mhz.
nanoseconds
Mhz memories bring their chip registered a number followed by a hyphen and another number
The latter is the correspoende to Nanos and you have to convert
Mhz
Mhz Table Nanos and
60 MHz 66MHz 17ns 15ns 13ns
10ns 100Mhz 80 Mhz
8.3ns 7.5ns 133Mhz 120 Mhz
Data Handling Capacity: like the memorais micro also has a width (W Memory), which is measured in bits Dimm memory handles Simm 64 Bits and 32 Bits.
Different Technologies
The memory just like the rest of the components of the PC, also had a history of technological development:
DRAM (Random Access Memory Dynamyc)
This type of memory used des the 80 so far in all the computers
This memory has a drawback is that stimulate (Refresh) permanently because it forgets everything.
As is stimulated: it requires a processor to order the dispatch of electric charges in this type of memory is known as static memory
Other disadvantages of this memory is that it is slow, the advantage is that it is cheap
Obviously having these disadvantages different technologies were incorporated to improve them.
FPM DRAM
The advantage of this memory is to ask permission once or take several consecutive data that came into use early nineties and I was successful in these modules are called SIMM FPM DRAM and can have 30 or 72 pins and is used in the Pentium I what I accomplish with this technology is to speed up the process of reading these reports and are not used more.
EDO DRAM
These reports appeared in 95, and became very popular as they were present in all Pentium MMX and I had the ability to locate a data while transferring another contrast to earlier that while data is transferred one SIMM EDO were bloqueaba.Estas
72-pin SDRAM
This report entered the market in years 97 and improved the speed the pace of work being equal to the speed Bus (FSB) is said to have the acapacidad of work at the same rate of mother to which they connect.
is coughing modules are 168 Pin DIMM SDRAM PC known as 66 and 100, 133, obviously if I install a 133 in a mother of 100 will run at 100Mhz.
DDR SDRAM
was achieved in this case that would make two one-touch transfer or clock ticking, this memory could reach speeds of 200 to 266 MHz, has an advantage over working in sync with the bus of the mother if this speeds up the memory but also has a downside too expensive. It is known as DDR SDRAM DIMM PC 1600 and PC 2100.
RDRAM
memory is very expensive and complex to manufacture and use Pentima IV processor running at speeds up to 800 Mhz modules called Rimm of 141 pins and a 16-anho bits, to fill a memory bank of 64 bits need to install 4 memories, this memory may be withdrawn from the market because it is so expensive
VIRTUAL MEMORY
We also what we call virtual memory also swapeo call. Creates the Windows virtual memory and disk space occupied it. If you arrive is to overcome this virtual memory disk capacity machine crashes, for which the only thing left is to reset it.
If we open many programs we are going to realize that when we use virtual memory the machine starts running slow or having our record speed decreases, We continue to work, but never walk as fast as when working with RAM or extended. Therefore to avoid this it is best to put more RAM in accordance with what the manual says mother.
or SRAM CACHE
The cache works just like virtual memory, we cache on the processor, disks and the mother and keeps us memory addresses. If you run a program in principle, we close and then re-run, the cache keeps us the location (address) in the record, when I ran it, and what we did with the program. It is much faster when we use a
program There are 3 types of cache:
L1 Cache
is divided into two blocks one contains the instructions and other data and when it comes to storage capacity is said to 2x16 Kb.
The L1 cache is located within the interior of the processor and runs at the same speed as the bus with capacities ranging from 2x8 to 2x64Kb
internal and external L2 Cache
The first cache were located on the motherboard then built into the processor, but not inside the processor die so it is more slower than the L1 cache, while the external is found on the motherboard.
The computers having cache the three technologies will be more rapid.
L3 Cache
Some micro level support but the L3 cache that is located on the motherboard
THE AMD 6k-3 supports this cache.
