Reading Journal Week 2 Processors - echadbourne/ChadbourneSYS-140 GitHub Wiki

Assignment Submission Link: https://docs.google.com/document/d/1EQUa3cov1oj8WAGDkrjCmfxefixNPYlqgi_AzzmGqtA/edit?usp=sharing

Processor Terms Definitions:

  1. Cache - A fast type of memory designed to increase the speed of the processor by holding information readily available.

  2. Clocking - A signal generated by the motherboard that transmits data in the form of ones and zeros. It can be illustrated by a sine wave.

  3. ALU - Arithmetic Logic Unit, responsible for the logic comparisons and calculations of the computer.

  4. Busses - Electronic lines that carry 1s and 0s throughout the processor. Number of lines is equal to the word size. Can be internal or external.

  5. Pipelines - Separate groups of internal busses that operate simultaneously.

  6. Graphics Processing Unit (GPU) - A video processor that assists in communication between the video adapter and the system processor. Can be separate or incorporated into the CPU.

  7. Processor Cooling - Refers to preventing the processor from overheating while working and possibly damaging itself. Can be achieved through a variety of passive or active methods, the most common being heat sinks and fans.

  8. Chipsets - One or more chips on the motherboard that work with the processor to perform certain functions of the computer, like memory and capacity of the motherboard

Processor Reading Notes:

Part 1: Processor Overview: The processor, also called a central processing unit (CPU) or a microprocessor, is the main portion of the motherboard and is responsible for performing calculations, executing instructions, and coordinating input and output. It is aided by electronic chips that are made to exact specifications. A processor is pictured below.

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My Response: I have a small raspberry pi computer, and I have also used one in a robotics class. I remember looking at it and thinking that the black chip in the middle with the company logo on it must be important. It's much smaller than the conventional computer, but I am guessing that that chip must be the CPU.

Part 2: Processor Basics: Processors come in multiple speeds, which are measured in gigahertz (GHz). Hertz is a measure of cycles per second, so one cycle per second is equal to one hertz. Buses are electronic lines in the processor that move around the data that the computer is using or computing. There are internal bus lines that move information around in the computer, and external lines that move information outside of the computer to be put somewhere else. Other parts of the processor are the ALU, control unit, registers, and I/O unit. The ALU is the arithmetic logic unit, which makes logical comparisons and does calculations for the computer. The control unit coordinates things in the processor, and the registers store bits to be processed. The I/O unit is responsible for data entering and exiting the processor. More bus lines mean the computer can move information faster. Below is an example of how the different amount of busses (like lanes on a road) can affect speed.

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Pipelines are groups of busses that are running at the same time. Different pipelines can do different things. For example, if a computer is trying to upload a photo in one application and send a letter in another, the information would be traveling in different pipelines.

My Response: The idea of Buses seems pretty straightforward to me. That information needed to be transmitted somehow, and electronic “roads” seem like a pretty logical way to do it. I also really liked the highway analogy for more buses meaning faster data transmission. That all makes sense to me.

Part 3: Cache: Cache memory is a type of memory designed to optimize the processor by holding short term information and constantly supplying it. There are 3 types of cache, L1, L2, and L3. L1 is integrated into the CPU, L2 is in the packaging but not in the CPU (on-die), and L3 is usually found in more powerful processors and is either in the housing or on the motherboard. Generally the more cache a system has the better it performs, but performance could also be related to the cache controller (the chip that manages the cache), system design, speed of the processor, and hard drive space. The image shows the hierarchy of data access (where it looks first for information).

image

My Response: I had heard the term cache before, but never really understood what it meant. Thinking of it as a short term memory really made sense to me, and I also thought of the term “clearing the cache” and what that meant. To me, it means clearing out information that may not be immediately useful to the computer to make room for information that is useful. Using that as context, the cache seems to make sense. Also, I liked the lemonade analogy for the hierarchy of data access.

Part 4: Clocking: A clock signal is generated by the motherboard to transmit data in the form of ones and zeros. I can be illustrated by a sine wave, as shown below. Modern CPUs can transmit data at 4 points during the sine wave, which can be seen in the illustration as dots along the wave.

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My Response: My Networking class has used the image of a sine wave in passing, so I had a moment of understanding when we got to this section of the reading. I also see where the term clocking comes from, since a clock completes a single revolution in a circle for every 12 hours. While it seems that there is no physical circular revolution in this context, I can see how a complete sine wave would constitute a clock cycle.

Part 5: Graphics Processing Unit (GPU): Graphics Processing Units (GPUs) are video processors that assist in communication between the video adapter and the system processor (CPU). They can come included with the CPU (these are called iGPUs) or you can get separate GPUs for your computer if it is not included. Modern GPUs contain many small core processors, and GPUs can also be used to boost general system performance (called General Purpose GPUs or GPGPU). A computer system can have multiple GPUs.

My Response: Sometimes when I hear terms relating to computer parts or building a computer, I hear the term “graphics card.” I know that this obviously has to do with the graphics the computer can handle, but I would love to know if it is the same as a GPU, related to the GPU, and what a different graphics card can do, as well as how to check what one you might have in your computer.

Part 6: Processor Cooling:A processor can easily overheat while working and needs to be cooled. Therefore, a variety of passive (ex. Heat sinks with no motors) and active (ex. fans) cooling methods can be used in addition to the computer turning off unused parts of the processor. The table below shows all of the ways a processor can be cooled, the most common ones being fans and heat sinks.

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My Response: When I got the raspberry pi computer that I mentioned earlier it came with a heat sink and a small fan in the case. Being a small computer that wasn’t going to do much, this is adequate. The heat sink is a block of metal with some ridges on the top. Imagine my surprise when I saw the giant heat sinks that they use on bigger computers. I found it very interesting.

Part 7: Chipsets: Chipsets are important chips on the motherboard that work with the processor to perform other functions for the computer. They are often located near the processor, like in the image below, and commonly have a heat sink on them. They also are usually specific to the processor being used.

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My Response: Reading back on the processor basics I remember chips like these being mentioned. This was a little confusing for me to read through though, since the definitions of chipsets weren’t totally clear on how many there typically are, and all of the things they do, among other confusing things I can’t put into words at the moment. I imagine we are going to go over this more in class though, so I will ask more specific questions as they come up.