What are pipes?

gyromind

Member
Jun 24, 2004
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Is it the amount of pixel shaders? What exactly do they do, and why is more better? Should I be concerned with a card that has 12 vs. one that has 16?
 

vshah

Lifer
Sep 20, 2003
19,003
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think of one pipe as a one conveyor belt in a factory. one belt can move a certain number of boxes, or pixels, in one second. if you have 16 pipes, you can move 16x as many pixels. 12 pipes = 12x the number of pixels.

thats avery basic example, but in short, everything else being equal (clock speeds, architecture) a card with 16 pipes will outperform a card with 12 pipes.

-Vivan
 

Marsumane

Golden Member
Mar 9, 2004
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Originally posted by: vshah
think of one pipe as a one conveyor belt in a factory. one belt can move a certain number of boxes, or pixels, in one second. if you have 16 pipes, you can move 16x as many pixels. 12 pipes = 12x the number of pixels.

thats avery basic example, but in short, everything else being equal (clock speeds, architecture) a card with 16 pipes will outperform a card with 12 pipes.

-Vivan

Good example. Basically the number of pipes, along with clock speed, memory speed, and memory bandwidth are the biggest things that you should consider in determining which card is better in any ONE generation of graphics cards from either NV OR ATI. (dont compare a gf4 w/ a 9600p just on these specs)

Think of it this way: Based on the above example, would u rather have 16 "pipes" working at 500mhz or 12 "pipes" also all working at 500mhz on drawing your scene?

Its the same as saying 16 "migrant workers" or 12 "migrant workers" all working on tying grapes working at 100 grapes/hr.
 

Regs

Lifer
Aug 9, 2002
16,665
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Like vshah and Marsumane stated. Pipeline's mean segments or stages. Like a 6800GT can spread its processes over 16 segments instead of processing everything at once. The segment order, the available bandwidth that feeds these pipes, and the length of the pipeline for a particular application (in this case a certain video card), are also very important.

These pipelines are futher explained here on a anand.com article.
 

Whatsisname

Junior Member
Jul 21, 2004
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Yes. Pipe is just a term used to describe the logic circuitry responsible for doing calculations for a pixel.
 

Ages120

Senior member
May 28, 2004
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It's the assembly line for a pixel. More pipelines means you can draw more pixels per clock cycle. All the pipelines are identical taking advantage of parallelism that this kind of operation is capable of. Only problem is more pipelines ussually means higher transistor counts, greater power consumption, and most of the time more heat.
 

CaiNaM

Diamond Member
Oct 26, 2000
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Originally posted by: Ages120
It's the assembly line for a pixel. More pipelines means you can draw more pixels per clock cycle. All the pipelines are identical taking advantage of parallelism that this kind of operation is capable of. Only problem is more pipelines ussually means higher transistor counts, greater power consumption, and most of the time more heat.

assembly line is a good analogy.... however the rest of your statement is very misleading. you have to consider the power of the pipes, not necessarily just the # of pipes (unless your comparing the exact same architecture) - kind of like the # of "assembly lines" doesn't necessarily mean something puts together faster; it depends on the # of workers on each assembly line ;)

for instance, a single nv40 pipe is much more capable of processing shaders than a single nv35 pipe...

reg's link is a very good example, however for more in depth you might google for the nv40 article on 3dcenter (very thorough).
 

BFG10K

Lifer
Aug 14, 2000
22,709
3,002
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Pixels and texels form the basis of any 3D scene (i.e. they fill your monitor with colours).

In the good old days pipes were only capable of performing simple drawing/blending operatings on pixels/ texels.

These days they're usually replaced with pixel shaders that can run a bunch of instructions for each pixel/texel to do nifty effects.

The more pipes you have, the more work you can perform in one clock cycle.