The buffer here "slows down" the speed of input. As mentioned in class, the speed of the whole pipeline depends on the slowest stage, that is, the blue blocks in the picture. If there is no buffer, the high-speed input floods into the slowest stage. Obviously, the blue stage has its hands full and has to drop the coming jobs. Although the picture of non-buffered pipeline may look like the same (only the gaps between the orange and blue parts are gone), there are actually jobs dropped.
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chaihf
In my opinion, Buffer is critical for pipeline in the following aspects:
1. From the slides, we could see the buffer always ensures the immediate input for the slowest stage(blue block), so we are able to keep the slowest stage busy to maximum efficiency.
2. I think it also eases programming. Say if you have no buffer, it would be tricky to coordinate different stages in the pipeline. You have to know when the blue block is available before getting results from orange block.
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jinsikl
I think another reason for buffering that hasn't mentioned that it allows for bursts of activity to be handled more efficiently. In the example above, we see that the processor can only send four messages consecutively before it has to wait for the blue block. If we are able to buffer messages, than the processor can send many more messages consecutively before waiting. So I think buffering will be beneficial when we expect a slow stream of requests interleaved with short bursts of high activity.
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shabnam
So in a way the critical path determines the overall speedup for the whole pipeline.
The buffer here "slows down" the speed of input. As mentioned in class, the speed of the whole pipeline depends on the slowest stage, that is, the blue blocks in the picture. If there is no buffer, the high-speed input floods into the slowest stage. Obviously, the blue stage has its hands full and has to drop the coming jobs. Although the picture of non-buffered pipeline may look like the same (only the gaps between the orange and blue parts are gone), there are actually jobs dropped.
This comment was marked helpful 0 times.
In my opinion, Buffer is critical for pipeline in the following aspects: 1. From the slides, we could see the buffer always ensures the immediate input for the slowest stage(blue block), so we are able to keep the slowest stage busy to maximum efficiency. 2. I think it also eases programming. Say if you have no buffer, it would be tricky to coordinate different stages in the pipeline. You have to know when the blue block is available before getting results from orange block.
This comment was marked helpful 0 times.
I think another reason for buffering that hasn't mentioned that it allows for bursts of activity to be handled more efficiently. In the example above, we see that the processor can only send four messages consecutively before it has to wait for the blue block. If we are able to buffer messages, than the processor can send many more messages consecutively before waiting. So I think buffering will be beneficial when we expect a slow stream of requests interleaved with short bursts of high activity.
This comment was marked helpful 0 times.
So in a way the critical path determines the overall speedup for the whole pipeline.
This comment was marked helpful 0 times.