3 ms·

hey sir, first thank you so much for your typing, this must cost you some times, really appreciated actually trying to help a stupid guy! I googled another sev

hey sir, first thank you so much for your typing, this must cost you some times, really appreciated actually trying to help a stupid guy! I googled another several hours till now, yes still confusing as hell, but I indeed learned a lot new things regard "Memory", I think my problem lies in PC architecture, why engineers design a PC like this bla bla, and I indeed know its because practical usage to do this lol, just can't get the real CORE of WHY this. I understand most part of what u said, yes its all about efficiency and best practices. What I still confused about is am I right about the wires things? For example, I don't care about the efficiency or engineering reasons to have "individual Memory" for computers, now I want to build my own PC, I just want to use the wires inside a CPU to do everything! Say, we have a ton of wires now in my CPU, fist input 2 8 bits number, 00000011 and 00100101, because the wires got voltage when it got "1", this wire will always keep at "1" if I don't rewrite any of these wires to another value. So now let's send this 2 number to an adder, so maybe adder need locate the wire numbers (in this case, #1-16), or adder need physically wired onto those 16 lines or whatever,(I think this way is impossible, because if connected, the charges will flow through already, make it harder to add them together?! ) Anyway, if first method is doable, then in my CPU, I done the calculation without any Memory system lol. If I need more numbers, just use more wires! (sry I don't know how many such circuits inside a CPU, I think its limited though) ---------------------------------------------------------------- I think there must be errors of this such logic, just I don't where :( I can't find the exact thing online, I think I am just a fool, because maybe nobody think like this, I fall into some wrong circle. Maybe at the very end of day, just try to convince myself like this: why PC need memory system? because we need store data. Why not just use wires inside a CPU? Because its not efficient lol. Thank you for your help again, I think I will face more problems along the way, what a though journey to self taught CS :(

pwg 8y ago
> What I still confused about is am I right about the wires things? No, you are not right about the wires thing. In my other answer, one of your statements implied you seem to think of wires and transistors as the same, but they are not. Wires transport voltages around between the transistors, the transistors switch on/off depending upon what voltages the wires transport to them. The combination of the wires transporting different voltages at different points in time, and the transistors switching on/off dependent upon the transported voltages, is what creates the basic building block of a CPU. > Anyway, if first method is doable, then in my CPU, I done the calculation without any Memory system lol. Is your real question here this one: "Why is the memory located in a separate box apart from the CPU"? Because if that is your real question, then there is a good explanation of why this is so. It is so because the best design of the circuits for the CPU portion is different from an engineering perspective than the best design for the circuits for the RAM portion. And due to restrictions on integrated circuit manufacturing, it is easier and cheaper to build the two components separate, using different integrated circuit techniques, and then connect them together via bus lines, than to build them all together in one single component. The circuit designs for the CPU center around fast operation often at the expense of additional energy consumption. The circuit designs for bulk memory (RAM) center around much lower energy consumption (often at the expense of some speed of operation) and very high density packing of storage cells. Attempting to mix both of these techniques on a single chip is possible, but much more expensive and difficult than building them independently on separate chips. But, also, there have been experimental CPU designs that attempt to do some of what you suggest, the (generally) external RAM cells are actually built on the CPU itself, right near where the data stored therein will be used by the CPU. So what you suggest has been done, it is just not the design that gained traction for our current IBM-PC architecure PC's. Also, one other item to consider. If you build a CPU and RAM on the same chip, then to offer different amounts of RAM in the market, you have to design and build different chips. But if you build the CPU separate from the RAM, you can change the amount of RAM in a system by adding/subtracting RAM modules (presuming the system was designed with plugs for adding/subtracting RAM modules) while only having to build one kind of CPU chip, and one kind of RAM module. Lower cost of production, much more market flexibility.
salawat 8y ago
Hmmm. Well. You're getting closer at least, and you're at least poking the right places of the field for answers, as computer architecture should get you a great deal more insight into what constitutes a CPU. One thing that you might help is to look into Integrated Circuits as well. One thing many don't actively realize is that what we call a CPU in a computer in not the only "processor" in a computer. There are other, more specialized processors which are responsible for providing interfaces between the CPU and hardware peripherals, but which are far more tightly constrained in what they can do. Best I can tell you for now though is that for the most part, you'll rapidly run into non-computing related problems the more you Try to cram into a processor die. Physics still apply, and computation creates heat. Heat degrades the performance of the system, and the more transistors you pack into the same area, the harder it is to keep cool, fabricate accurately, and guarantee the life time of. Also, on die memory opens you up to problems in term of actual circuit layouts. There have been designs where certain alignments of values in the physical chunk of Silicon can have undesired side effects on values stored near them. Rowhammer I believe the phenomena is called. So, specialization ANF separation of concerns won the day. Hope you find what you're looking for!

pwg 8y ago

> What I still confused about is am I right about the wires things? No, you are not right about the wires thing. In my other answer, one of your statements implied you seem to think of wires and transistors as the same, but they are not. Wires transport voltages around between the transistors, the transistors switch on/off depending upon what voltages the wires transport to them. The combination of the wires transporting different voltages at different points in time, and the transistors switching on/off dependent upon the transported voltages, is what creates the basic building block of a CPU. > Anyway, if first method is doable, then in my CPU, I done the calculation without any Memory system lol. Is your real question here this one: "Why is the memory located in a separate box apart from the CPU"? Because if that is your real question, then there is a good explanation of why this is so. It is so because the best design of the circuits for the CPU portion is different from an engineering perspective than the best design for the circuits for the RAM portion. And due to restrictions on integrated circuit manufacturing, it is easier and cheaper to build the two components separate, using different integrated circuit techniques, and then connect them together via bus lines, than to build them all together in one single component. The circuit designs for the CPU center around fast operation often at the expense of additional energy consumption. The circuit designs for bulk memory (RAM) center around much lower energy consumption (often at the expense of some speed of operation) and very high density packing of storage cells. Attempting to mix both of these techniques on a single chip is possible, but much more expensive and difficult than building them independently on separate chips. But, also, there have been experimental CPU designs that attempt to do some of what you suggest, the (generally) external RAM cells are actually built on the CPU itself, right near where the data stored therein will be used by the CPU. So what you suggest has been done, it is just not the design that gained traction for our current IBM-PC architecure PC's. Also, one other item to consider. If you build a CPU and RAM on the same chip, then to offer different amounts of RAM in the market, you have to design and build different chips. But if you build the CPU separate from the RAM, you can change the amount of RAM in a system by adding/subtracting RAM modules (presuming the system was designed with plugs for adding/subtracting RAM modules) while only having to build one kind of CPU chip, and one kind of RAM module. Lower cost of production, much more market flexibility.

salawat 8y ago

Hmmm. Well. You're getting closer at least, and you're at least poking the right places of the field for answers, as computer architecture should get you a great deal more insight into what constitutes a CPU. One thing that you might help is to look into Integrated Circuits as well. One thing many don't actively realize is that what we call a CPU in a computer in not the only "processor" in a computer. There are other, more specialized processors which are responsible for providing interfaces between the CPU and hardware peripherals, but which are far more tightly constrained in what they can do. Best I can tell you for now though is that for the most part, you'll rapidly run into non-computing related problems the more you Try to cram into a processor die. Physics still apply, and computation creates heat. Heat degrades the performance of the system, and the more transistors you pack into the same area, the harder it is to keep cool, fabricate accurately, and guarantee the life time of. Also, on die memory opens you up to problems in term of actual circuit layouts. There have been designs where certain alignments of values in the physical chunk of Silicon can have undesired side effects on values stored near them. Rowhammer I believe the phenomena is called. So, specialization ANF separation of concerns won the day. Hope you find what you're looking for!