Memory access i s When memory is read or written  , a specific procedure is used to control each access to memory, which consists of having the memory controller generate the correct signals to specify which memory location needs to be accessed, and then having the data show up on the data bus to be read by the processor or whatever other device requested it.

Memory controller is the part of the system that controls the memory byt generating the necessary signals to control the reading and writing of information from and to the memory, and interfaces the memory with the other major parts of the system. It can be a separate chip or integrated into another chip, such as on the  microprocessor.

Memory controllers contain the logic necessary to read and write dynamic random access memory (DRAM), and to “refresh” the DRAM by sending current through the entire device. Without constant refreshes, DRAM will lose the data written to it as the capacitors leak their charge within a fraction of a second.

DRAM VS RAM :

DRAM is dynamic in that, unlike static RAM , it needs to have its storage cells refreshed or given a new electronic charge every few milliseconds.  RAM does not need refreshing because it operates on the principle of moving current that is switched in one of two directions rather than a storage cell that holds a charge in place.  RAM is generally used for cache memory, which can be accessed more quickly than DRAM.

Only one transistor and a capacitor are required per bit, compared to four transistors in RAM. This allows DRAM to reach very high density. Unlike flash memory, it is volatile memory , since it loses its data when the power is off.

in brief :

Advantages: it’s compatible with just about everything. Disadvantates: it’s the slowest of the memory types currently available and because it isn’t in demand

The clock speed that the component is rated for is at or below the speed at which the CPU has passed the manufacturer’s functionality tests when operating in worst-case conditions (for example, the highest allowed temperature and lowest allowed supply voltage)

overclocking is the process of running a computer component at a higher clock rate than it was designed for or was specified by the manufacturer.

Overclocking a computer’s processor or memory causes it to go faster than its factory rated speed. A processor rated at 2.4GHz might be overclocked to 2.5GHz or 2.6GHz, while memory rated at 200MHz might be pushed to 220MHz or higher. The extra speed results in more work being done by the processor and/or memory in a given time period, increasing the overall computing performance of the PC.

The most obvious reason to overclock a computer system is to squeeze some additional performance out of it at little or no cost. Overclocking the processor and system memory can significantly boost game performance, benchmark scores and even simple desktop tasks. Since almost every modern processor and memory module is overclockable to at least a slight degree, there are few reasons not to attempt it.

most important considerations for overclocking :

Heat :

The faster a computer goes, the more heat it produces. This is especially true when the voltage being fed to certain components is increased, a standard overclocking method. Excess heat in the processor, motherboard chipset or memory can cause crashes and system instability, and may be one of the limiting factors in determining the maximum overclock for a system so we need more cooling when overclocking

Power Supply :

Overclocking a computer system also increases the amount of power it draws, and this may lead to system instability if its old 300Watt power supply is not up to the task. If overclocking a modern Pentium 4 or Athlon 64 system, plan on upgrading the power supply to at least 400Watts

amd processor is a  processor from amd company ‘ Advanced Micro Devices  ‘ .

AMD is the second-largest global supplier of microprocessors based on the x86 architecture after Intel Corporation .

examples :

• AMD Athlon microprocessors
• AMD Athlon XP microprocessors
• AMD Athlon 64 microprocessors
• AMD Athlon X2 microprocessors
• AMD Phenom microprocessors
• AMD Duron microprocessors
• AMD Opteron microprocessors
• AMD Sempron microprocessors
• AMD Turion microprocessors