Info: How do cpu's work? - Overclock.net

oc_faq · 02-24-05

Many people wonder how a computer works. I have learned some of the basics of this topic, but certainly not anywhere near as much as i'd like to know. Anyway, theres this part of the processor called the alu, or arithmetic logic unit. It calculates binary digits (bits), using logic gates. By calculate I of course mean add, subtract, multiply, and divide. It does NOT calculate bits with a place value after the decimal point greater than 0. That work is left to the fpu (floating point unit). Back on topic, the alu takes in a code stream, and a data stream. The code stream consists of +, -, x, and /. The data stream consists of numbers that the code stream adds, subtracts, multiplies, and divides. Keep in mind that these are all in binary. These bits are called "operands". Before the data bits reach the ALU they go into something called a register. They await going into the ALU in this. The p4 has somewhere around 120 of these, and from what I've read the first x86 processors only had around 8! They are set up like cpu caches in a way- there are a number of them, and the first is top priority, second register is second priority, and so on, and so forth. Anyway,they are Then, once they reach the ALU they are put into one of the input sides (not sure what to call them) as a code bit is put into another input side. (also, the data bits are sent in as a pair- something that i forgot to put on my diagram, sorry). After the data has been modified according to what the code bit says they may return to the register, or be written back into the RAM. The process repeats. There are other units rather than the ALU, as I mentioned erlier there is the FPU (floating point unit). From what I understand sse, and mmx are instructions for floating point units. AMD processors have 9 floating point units, so an AMD cpu can calculate 9 floating point operations in one clock cycle. Intel's have 6. I am not sure of how many ALU's are in either of these types of processors. And that should conclude it. (in case this was to hard to visualize i have included a diagram). HOPE THIS WAS A HELP TO YOU

Contributed by snake_griffon

PCNerd · 02-24-05

wonderful

rep4u!

PCNerd · 02-24-05

come on guys, this is an excelent FAQ!!!

*Mr.N00bLaR* · 02-24-05

Lol yes it is i gave it a 5 and a rep, good work man

**Burn** · 02-25-05

definitely clears some stuff up. good job!

*Inspire* · 02-26-05

Proper Mega! :) Ive repped you :)

MikeEnIke · 05-05-05

No frequently asked but it is greatly written REPS

n-sanity · 07-01-05

yes, good job man! rep 4 u

3000gt · 10-13-06

so like an amd 2.0 ghz is equal to an intel 3.0 ghz in sense of the floating point...lol

02-24-05	#1 (permalink)
oc_faq New to Overclock.net Join Date: Apr 2006 Posts: 85 Rep: 60 Unique Rep: 52 Trader Rating: 0	Many people wonder how a computer works. I have learned some of the basics of this topic, but certainly not anywhere near as much as i'd like to know. Anyway, theres this part of the processor called the alu, or arithmetic logic unit. It calculates binary digits (bits), using logic gates. By calculate I of course mean add, subtract, multiply, and divide. It does NOT calculate bits with a place value after the decimal point greater than 0. That work is left to the fpu (floating point unit). Back on topic, the alu takes in a code stream, and a data stream. The code stream consists of +, -, x, and /. The data stream consists of numbers that the code stream adds, subtracts, multiplies, and divides. Keep in mind that these are all in binary. These bits are called "operands". Before the data bits reach the ALU they go into something called a register. They await going into the ALU in this. The p4 has somewhere around 120 of these, and from what I've read the first x86 processors only had around 8! They are set up like cpu caches in a way- there are a number of them, and the first is top priority, second register is second priority, and so on, and so forth. Anyway,they are Then, once they reach the ALU they are put into one of the input sides (not sure what to call them) as a code bit is put into another input side. (also, the data bits are sent in as a pair- something that i forgot to put on my diagram, sorry). After the data has been modified according to what the code bit says they may return to the register, or be written back into the RAM. The process repeats. There are other units rather than the ALU, as I mentioned erlier there is the FPU (floating point unit). From what I understand sse, and mmx are instructions for floating point units. AMD processors have 9 floating point units, so an AMD cpu can calculate 9 floating point operations in one clock cycle. Intel's have 6. I am not sure of how many ALU's are in either of these types of processors. And that should conclude it. (in case this was to hard to visualize i have included a diagram). HOPE THIS WAS A HELP TO YOU Contributed by snake_griffon Attached Thumbnails Last edited by BFRD : 05-25-06 at 09:30 PM

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Info: How do cpu's work?

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