Hello, everyone! I’ve been doing some research into computer hardware lately, and one thing that I keep coming across is this idea that the speed of a processor, while important, isn’t the only thing that affects a computer’s overall performance. I’m having a bit of a hard time wrapping my head around this because I always thought that a faster processor meant a faster computer. Can anyone explain why this isn’t necessarily the case? I’m really interested to learn more about this!
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Think of PC like of a wood factory. You have a hard drive thats a warehouse with stacks of wood, then another building with central processing unit, which is wood cutting machine, and memory which is space directly around the machine. You need to deliver wood from warehouse to the building with the machine, feed the machine and unload the processed material.
If machine is too slow, then no matter how fast you deliver wood or how much space there is, you’re not gonna get much done.
On the other side, if your machine is super fast, but it’s placed in a crammed space, it’s gonna be running on half of its efficiency because its gonna be hard to keep up with loading it with wood and unload the processed boards.
If machine is fast with ample space but warehouse has few loading spaces or trucks in the warehouse are few or slow, then you’re not gonna have fast enough access to material for processing so the machine is gonna constantly wait for material to arrive.
Good PC have balanced components that allow each other to reach optimal performance.
Think of additional components like of machines that take wood from your CPU and do other stuff. Like GPU would paint the boards. Speed of producing boards should be balanced with the speed of painting the boards, otherwise you leave performance on the table.
Doesn’t matter how fast you think(processor speed) if you can’t remember anything(memory).
Then, you need to process the thoughts into a usable format. (Display, storage).
Then, if your storage/memory is slow, it doesn’t matter how fast you put out the data. You’re limited by the speed of your storage/memory.
On top of that, if the infrastructure you use to move/communicate the data is inefficient, like postal mail or rugged path to walk (motherboard), then you are limited by that.
Similarly, you’ll have issues with data transfer if you aren’t communicating efficiently in a way people expect (network/wifi). Trying to transfer a large amount of data over a distance in a tiny cup (10 megabit network) vs. a truck (10 gigabit network).
Then maybe you have to do some complex math your brain(cpu) isn’t very good at. On top of that, you’re a terrible artist. So you grab an artist to assist you (video card). They specialize in taking the directions you give them and making it into a foem you can see better than your cpu brain.
It’s more complicated than that, of course, but this is eli5.
It’s just like our body. You brain is not only the most important organ for better performance of your body, There are many other organs that are the important factor in body’s performance.
It’s like Stephen hawking. His brain was fast but his body couldn’t get things recorded as quick.
Imagine that your CPU is your heart.
You have a rask to transport a lot of bricks form A to B.
Your heart might make you able to run faster or for longer before you cannot go anymore.
But your arms determine how much you can carry each tine
Your legs determine if you tired as well, and how long steps you can take.
In the same way as the human body, the computer also have many factors in determining how fast it can complete a task.
To put it simply, the CPU is your brain. There are other components in your computer e.g the Graphics card, which process images and would be akin to your eyes. The RAM is your short term memory and the hard drive is your long term memory. If you have a really good brain, but a bad memory recalling ability, it might take a while for you to recall something and slowing you down, i.e a slow PC. Same with the graphics card, if you can’t process the images fast enough it becomes laggy and start stuttering.
Your computer is a highway. A better processor can create more cars to use this highway, and stuff like memory and storage are little towns that branch off this highway, filling cars with goods to ship back to the processor. A great processor and a bad memory is like trying to push 8 lanes of highway traffic onto a two lane street: no matter how many highway lanes of cars you add, the entire system is limited by that two lane street.
Imagine you have an abacus.
* Processor speed is how fast you can move your hand to push a bead around he abacus.
* RAM is how many beads are on the abacus.
You want to have both to be able to do calculations efficiently.
For instance:
* A super fast hand with 0 or 1 bead won’t really do any good.
* And a hundred beads with the only handy person on vacation won’t do anything either.
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(Computers now work on numbers like billions and trillions or higher etc, so it is more like “Processor speed is how many thousands of hands you have manipulating abacusses” and “RAM is how many warehouses full of abacuses you have.” and at that point my analogy starts to break down.)
Take a look at the Nintendo Switch. The CPU is an ARM quad core processor operating at just a little more than 1 GHz. Apparently, one core of the CPU is dedicated to the OS.
Now let’s look at the XBox 360. The CPU uses the PowerPC architecture, and has three cores running at 3.2 GHz
The Switch has a number of games on it that were also available for the 360, but they usually run at a higher resolution or framerate (obviously, there are exceptions to this). The Switch does have a lot more RAM and a slightly better GPU, but even still the Switch is still able to “keep up” despite only playing with a total of 4 GHz as opposed to the 360’s total of 9.6 GHz. If CPU power was just about GHz, the XBox 360 would be easily twice as powerful as a Switch, when in reality the Switch is a bit more powerful due to the amount of RAM it has, but is otherwise kinda comparable to the 360.
In all honesty, two systems shouldn’t really be compared, but it is a good example of how different architectures and a decade of technological advancements is more important than how many GHz each machine has.
Think of your computer as a tiny office full of people.
The CPU is the executive and computation department. It crunches numbers, but it has very limited space for materials. The CPU also has executive capacity to control the rest of the computer.
Memory is the rapid-access records department. Because the CPU has limited space, it needs a place it can quickly access. The memory department is full shelves that are very close to the CPU department. The memory department is in charge of storing and fetching stuff from the shelves, but the CPU department tells them where to put things. When the office closes for the evening (when the computer is shut down), everything in the memory department is sent to the shredder.
The SSD/Hard Disk departments are warehouses for long term storage. The CPU sends data here that needs to be maintained, even when the office closes. The SSD department is quite a bit faster at retrieving materials than the Hard Disk department, but the Hard Disk department tends to have more square footage.
The Graphics Card department is in charge of what is shown to customers. Everything a customer see goes through this department. Pretty much all Graphics Card departments can handle basic requests like displaying photos and video, but it takes specialized staff to animate game instructions sent from the CPU department in real time.
So given what we know about this office, let’s think about how each affects speed.
An better CPU department means you can crunch numbers faster, but since there is limited space there, what happens if the CPU is done calculating, but the Memory department isn’t big enough to hold the result? The CPU will have to send some of the data off to the SSD warehouse before it can send more results to Memory. The SSD department is pretty quick, but you’re still dealing with a warehouse, and the SSD department is a warehouse, so it’s in a separate building. The CPU ends up waiting on the Memory department to clear out space so it can send over more results.
From the example above, we can see how a fast SSD/Hard Disk has a cascading effect on Memory, and therefore the CPU. If the CPU asks the Memory department to clear space, that data has to go to the SSD/Hard Disk warehouse. So the entire operating can end up waiting on the warehouse.
The Graphics Card department is a little bit special. These departments vary pretty widely depending upon what type of tasks the office will perform. Pretty much all of these departments have projectors for photos and film, but gaming is different. Gaming comes in as a set of descriptions of the scene, and the Graphics Card department has to literally draw each one. To do this, they employe a massive number of workers. They split the scene up into little parts, and dispatch each part to a small working group so they all work in parallel. The results are sent back to the head of the department to be assembled.
Because of the complexity of this work, some Graphics Card departments have their own, separate Memory department. If your department drawing a very large, complex scene multiple times per second, you need *very* rapid access to storage so you can rapidly work through frames of the scene and put them in storage to be displayed on the screen very quickly.
So if the Graphics Card department isn’t able to keep up with the requests from the CPU (who is managing everything), the customer will have to wait for that department to catch up.
Hopefully the picture is becoming clear that a computer is a complex system with interconnected dependencies. It’s worth noting though that there is some flexibility in that interconnected nature. You can usually identify one department that is most frequently holding the rest up. Upgrading that *single* component *will* have the net effect of speeding up the entire computer.
A good example of this is moving from a hard disk to an SSD. Hard disks are literally metal boxes with spinning plates in them. These plates work a bit like an old vinyl record. Data is encoded in rings of magnetic charges on the plate. If you want to read data from a hard disk, a little arm has to sweep over to the ring where the data is stored. If the data is spread out across multiple tracks, this little arm has to move around. That little arm can only move back and forth so fast before its inertia becomes too great. Wave your arm back and forth really quickly. Faster… Faster! Try to do that 100 times per second. See how much effort it takes? That’s going on inside a hard disk all the time.
An SSD, by contrast, has no moving parts. Every internal component is made from a semiconductor. The only movement is at an atomic level, and atoms have very, very little mass. This means they have almost no inertia, so they can switch much faster than a tiny metal arm.
A lot of a computer’s time is spent waiting on long term storage. If you’re using a hard disk for long term storage, then you’ll spend even more time waiting on that aspect of the computer’s operation. Upgrading to an SSD will often result in a massive improvement in performance because SSDs are >10 times faster than hard disks when it comes to grabbing random stuff from the warehouse.
Contrast this with a CPU upgrade. Most modern CPUs are incredibly fast and are actually multiple CPUs packaged as one CPU. They can compute so quickly that most modern CPUs spend the majority of their time sitting idle. Tasks that do require the CPU execute more quickly, but instead of waiting 300 milliseconds, we wait 250 milliseconds. It can be difficult to notice the difference.
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