Computer Components Basic Info
 

Processors

Here is a quick rundown of all the different sockets and slots for processors:

Socket 1
This is an old slot. Its found on 486 motherboards and supports 486 chips, plus the DX2, DX4 Overdrive. It contains 169 pins and operates at 5 volts. The only overdrive it will support is the DX4 Overdrive.

Socket 2
This Intel socket is a minor upgrade from the Socket 1. It has 238 pins and is still 5 volt. Although it is still a 486 socket and supports all the chips Socket 1 does, it has the minor addition of being able to support a Pentium OverDrive.

Socket 3
Another Intel socket, containing 237 pins. It operates at 5 volts, but has the added capability of operating at 3.3 volts, switchable with a jumper setting on the motherboard. It supports all of the Socket 2 processor with the addition of the 5x86. It is considered the latest of the 486 sockets.

Socket 4
We move into Pentium class machines with the Socket 4, by Intel. This socket has 273 pins. It operates at a whopping 5 volts. Due to this voltage, this socket basically had no where to go but the history books. It only supports the low-end Pentium 60-66 and the Overdrive because these chips are the only Pentiums operating at 5 volts. Beginning with the Pentium-75, Intel moved to the 3.3 volt chip.

Socket 5
This socket operates at 3.3 volts with 320 pins. It supports Pentium class chips from 75MHz to 133MHz. Newer chips will not fit because they need an extra pin. Socket 5 has been replaced by the more advanced Socket 7.

Socket 6
You might think this is a nice Pentium socket class, but it is meant for 486's. It is only a slightly more advanced Socket 3 with 235 pins and 3.3 volt operation. This socket is forgotten. The market never moved to use it because it came out when 486's were already going of out style and manufacturers couldn't see pumping money into changing their designs for a 486.

Socket 7
Socket 7 is the most popular and widely used socket. It contains 321 pins and operates in the 2.5-3.3 volt range. It supports all Pentium class chips, from 75MHz on up, MMX processors, the K5, K6, K6-2, K6-3, 6x86, M2 and M3, and Pentium MMX Overdrives. This socket is the industry standard and is being used for sixth-generation chips by IDT, AMD and Cyrix. Intel, however, decided to abandon the socket for it's sixth-generation lineup. Socket 7 boards incorporate the voltage regulator which makes voltages lower than the native 3.3 volt possible.

Socket 8
This is a high-end socket used primarily for the Pentium Pro. It has 387 pins and operates at 3.1/3.3 volts. This socket only handles the Pentium Pro. It is designed especially to handle the dual-cavity structure of the chip. Since Intel decided to move on to Slot 1, the Socket 8 is a sort of dead end, although there are plans to release a Pentium II overdrive for it.

Slot 1
Intel completely changed the scene with this slot. It, instead of accepting the usual square chip with pins on the bottom, takes the processor on a daughtercard. The daughtercard allows fast communication between the processor and the L2 cache, which lies on the card itself. The slot itself has 242 pins and operates at 2.8-3.3 volts. The Slot 1 is used mainly for the P2,P3 and Celeron, but Pentium Pro users can use the slot by mounting their processors in a socket 8 on a daughtercard which is then inserted into the Slot 1. This gives Pentium Pro users the ability to upgrade later.

Slot 2
A chip packaging design used in Intel's newer Pentium II chipsets, starting with the Xeon CPU. While the Slot 1 interface features a 242-contact connector, Slot 2 uses a somewhat wider 330-contact connector. The biggest difference between Slot 1 and Slot 2, though, is that the Slot 2 design allows the CPU to communicate with the L2 cache at the CPU's full clock speed. In contrast, Slot 1 only supports communication between the L2 cache and CPU at half the CPU's clock speed.

Socket 370
Socket 370 is named for the number of pins this certain socket has.  After Intel found a way to cheaply put the cache of a CPU on the die, it found that a separate PCB for the processor was costly and useless.  Intel then took the Chip off of the PCB, and created Socket 370.  It's basically Socket 7 with an extra row of pins on all four sides.  The first processors to use it were the PPGA Celeron's, then quickly following were the FC-PGA Pentium iii processors along with the Celeron II line.  Socket 370 chips can be placed on a daughtercard just like Socket 8 chips in order to fid into a Slot 1 Interface.  Socket 370 is also made to use previous Socket 7 heatsinks, although most of them are too small to cool these modern processors. This Socket is used for Pentium iii, Celeron, and Celeron II processors.

Slot A
This is the new proprietary slot design AMD decided to use with the Athlon processor. Design wise, it is similar to the Slot 1. But, Slot A uses a different protocol, called EV6. Using this bus protocol, which was created by Digital, AMD can increase the RAM to CPU data transfer to 200MHz, giving us a 200MHz FSB (front side bus). AMD had to use their own Slot design since Intel had effectively patented the Slot 1 design so that AMD could not use it. Now, with the Athlon becoming more popular, more and more Slot A boards are coming out so that systems based on the Athlon are becoming more common.

Socket A
Just as Intel found it's cheaper to leave the PCB off of it's processors, AMD did the same.  It's Athlon and Duron processors using the .18 micron process both use Socket A.  It supports the 200MHz EV6 bus, as well as the new 266MHz EV6 bus.  Unlike Socket 370, it requires a slight modification a Socket 7 heatsink in order to be used properly.  Also, unlike Socket 370, there is no daughercard that provides Socket A chips to be plugged into Slot A interfaces.  Socket A also offers many more pins than Socket 370, 462 in total.  Socket 370 chips can not plug into Socket A, and vise-versa. This Socket is used for both Athlon and Duron Processors.

Slockets
The slocket is a weird little contraption. Its basically Slot 1 to Socket 370 adapter. It comes in other flavors too. By doing a bunch of electrical work-arounds, it is able to successfully reroute the currents and make the different interfaces adapt. Some of them even have cute little electrical tricks that allow things such as dual-processor or overclocking despite the clock-locking.

Okay, here are just a few notes on internal structure of microprocessors. Overall, this kind of stuff isn't too important to users, but in order to understand all the hype about the latest chips, it helps to know this. It will help you understand the specs a little better, and you can impress your friends.

Clock Speeds

Clock speed is basically how many times the CPU "ticks" per second. Every time it ticks (you don't hear the tick) an instruction gets performed. The clock speed is determined in Megahertz (MHz), which is a million cycles per second. Therefore, a 200MHz Pentium ticks 200 million times per second.

Although clock speed isn't the only determining factor for performance and speed, it means an awful lot. The faster the clock speed, the faster the computer.

Since Intel chips are the standard, it's chips are named by their clock speed. For example, the Pentium-200 is a Pentium chip that operates at 200 MHz. Intel's competitors use a P-Rating (PR) System. The PR system basically compares the chip with the equivalent Intel chip. For example, the AMD K5 was released in a PR166 version. This means that it runs about the same speed as an Intel Pentium 166, although the K5 itself actually runs at 116.7 MHz. Cyrix continues to use this speed rating system, although AMD decided to abandon it upon the release of the K6.

Cache Memory

Your SIMM chips, although fast, don't supply the processor the data it needs fast enough for it. Therefore, many CPUs comes with their own internal cache memory. This memory helps speed up its task considerably.

The Level One cache runs at the processor's own clock speed, so is very fast. This cache is split up into two sections, one for data, the other for instructions. The more level one cache you have, the faster the chip.

Computers usually come with secondary, or Level Two, cache. This cache resides on the motherboard and helps the CPU along, but is confined to the motherboard's slower speed. To get around this limitation, the Pentium Pro and Pentium II have their own built in level two cache. The Pentium II and later chips will house the level two cache in the cartridge along with the CPU, therefore bypassing the motherboard altogether. Some Super 7 systems have chips that have built on L2 cache AND on-board cache. With this setup, the motherboard cache becomes level 3 cache, or L3 cache.

Architecture

A chips architecture determine how it processes instructions and data. Modern chips use pipelines which are multistaged allowing more then one instruction to be acted upon at a time. To keep the lines full of data, the chip will guess on what's to come. If it misguesses, it must go back and redo the work. The better CPU's do not flub very often. When you see the specs for the newest chips, they will usually mention some kind of prediction and error correction mechanisms.

Density

As processor become newer and more advanced, the density of the transistors inside increases. The chip needs to perform millions of calculations and synchronize between the transistors. Therefore, reducing the distance between the transistors helps things perform better. Older chips had 1 micron between transistors. Although this isn't much, it is a lot in the world of CPU's. Today's modern chips have distances of about 0.35 micron and the newest models boast 0.25 micron density. IBM, with the use of copper wiring, promises chips to get down to 0.18 micron.

MMX Technology

Multimedia Extension (MMX) Technology is a new breed of instruction built in to the newest Pentiums and virtually all later chips. MMX is an extension off the x86 instruction set that allows bytes of data, or instructions, to be packed together into a single register and operated on as one set of data, therefore reducing the amount of work that the chip has to do and allowing it to do more. MMX is thought to be mainly an improvement in multimedia performance, but this is not necessarily true. Its just that these types of applications stand to benefit most from this type of data handling. Such applications need to be specially designed to take advantage of MMX, and many vendors are releasing MMX enhanced software.

How it Works:

The following information is provided by Intel.

The Pentium processor with MMX technology has three primary architectural design enhancements.

• New Instructions Intel engineers have added 57 powerful new instructions specifically designed to manipulate and process video, audio and graphical data efficiently. These instructions are oriented to the highly parallel, repetitive sequences often found in multimedia operations.
• SIMD Today's multimedia and communication applications often use repetitive loops that, while occupying 10 percent or less of the overall application code, can account for up to 90 percent of the execution time. A process called Single Instruction Multiple Data (SIMD) enables one instruction to perform the same function on multiple pieces of data. It allows the chip to reduce compute-intensive loops common with video, audio, graphics and animation. As an analogy, consider a drill sergeant telling an entire platoon, "About face," rather than commanding each individual soldier one at a time.
• More Cache Intel has doubled on-chip cache size to 32 KB on the Intel Pentium processor with MMX technology. Now, more instructions and data can be stored on the chip, reducing the number of times the processor has to access slower, off-chip memory areas for information.

 

 

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