The microprocessor, or simply the mike, is the brain of the computer. It is a chip, a type of electronic component in whose interior is existed by thousands (or million) of elements called transistors, which combination allows to realize the work that has the entrusted chip.

The mikes, since we will call them from now on, usually have form of square or black rectangle, and go or on an element called socket (socket in English) or soldiers in the badge or, in case of Pentium II, shoves inside a species of cartridge that gets connected to the motherboard (although the chip in itself is welded inside the above mentioned cartridge).

Sometimes to the mike he is named "the CPU" (Head office Process Unit, Central process unit), although this term has certain ambiguity, since also it can refer to the whole box that contains the motherboard, the mike, the cards and the rest of the principal circuitry of the computer.

The speed of a mike measures itself in megahertzes (MHz) or gigahertzios (1 GHz = 1.000 MHz), although this is an only one measurement of the brute force of the mike; a simple and antiquated mike to 500 MHz can be much slower than one more complex and modern (with more transistors, better organized...) that goes to "only 400 MHz. It is the same that happens with the car engines: an American engine of the 60s can have 5.000 cm3, but it does not have anything that to do against a current multivalve of "only 2.000 cm3.

Due to the extreme difficulty of making electronic components that work at the immense speeds of habitual MHz nowadays, all the modern mikes have 2 speeds:

• Speed interns: the speed to which the mike works internally (200, 333, 450... MHz).
• External speed or of the bus: or also "speed of the Federal Security Service"; the speed to which they communicate to themselves the mike and the motherboard, to be able to low the price of the price of this one. Typically, 33, 60, 66, 100 ó 133 MHz.

The number for which the external speed multiplies or of the badge to give the intern or of the mike is the multiplier; for example, a Pentium III to 450 MHz uses a speed of 100 MHz bus and a multiplier 4,5x.

In a mike we can differentiate diverse parts:

• the encapsulated one: this is what it surrounds to the silicon waffle in itself, to give him consistency, to prevent his deterioration (for example for oxidation with the air) and to allow the linkage with the external connectors that will connect it to his socket or to the motherboard.
• the cache memory: a memory ultrarrápida that uses the mike to have to hand certain information that most likely will be used in the following operations without having to come to the memory RAM, reducing the waiting time.
  All the mikes "compatible PCs" from 486 possess at least the called internal cache memory of the first level or L1; that is to say, which is closer to the mike, so much that is encapsulated along with him. The most modern mikes (Pentium III Coppermine, Athlon Thunderbird, etc.) include also in his interior another level of cache memory, bigger although slightly less rapid, the cache memory of the second level or L2.
• the mathematical co-processor: or, more correctly, the FPU (Floating Point Unit, Unit of Floating comma). Part of the mike specializing in this class of mathematical calculations; formerly it was in the exterior of the mike, in another chip.
• the rest of the mike: which has several parts (unit of points, records, etc.) that it is not worth detailing here.

It must be born in mind that a computer with a mike to 600 MHz will never be the double of rapid that one with a mike to 300 MHz, it is necessary to bear much in mind other factors as the speed of the badge or the influence of other components.

This is not born scarcely in mind in the index iCOMP, a table or graph of values of the supposed yield of the mikes marks Intel. It is much used by Intel in his literature, although it is not by no means representative of the final yield of a computer with any of these mikes.

In fact, the differences are very exaggerated, by means of realizing tests that almost only depend on the mike (and not of the motherboard, the videocard, the hard disk...), therefore it always seems that the yield of the computer will grow linearly with the number of MHz, thing that never happens practically. A computer with Pentium MMX to 233 MHz is only 3 ó 4 % better than one to 200 MHz, and not 16,5 % of his difference of MHz neither nor 11,5 % of his indexes iCOMP. It will seem incredible, but it is like that.

We go, that if they want to sell to him a computer with the argument that it has x MHz more, or an index iCOMP immensely, prove to be very skeptical to him. Better a computer with all his regular components (a lot of memory, good videocard...) that a utensil to many MHz.