We Do · Could This Class Run Its Own AI?

Why a Machine Has Two of Each

A computer built for this work carries two processors and two kinds of working memory. That is a strange thing to build. Nobody puts two engines in a car and asks the driver to guess which one to use. So it is worth asking why the duplication exists, because the two answers are not the same answer, and knowing them is the difference between guessing at a spec sheet and reading one.

Start with the processors. The difference between a CPU and a GPU is not that one is newer or better. It is what kind of work each one is shaped for.

A CPU has a small number of lanes, and each one is extremely fast. That design suits work where the second step needs the answer from the first. Opening a file, deciding what to do next, following instructions in order. Most of what a computer does all day looks like that, which is why no machine has ever stopped needing a CPU.

A GPU is built the opposite way. It has thousands of lanes, each slower than a CPU lane, all performing the same operation on different numbers at the same instant. That arrangement is useless for work with a queue in it. It is enormously powerful when nothing has to wait.

Running a model is the second kind. Producing a single word means multiplying an enormous quantity of numbers together, and almost none of those multiplications depends on the result of another. They can all happen at once. Deciding the color of every pixel on a screen has exactly that shape too, which is why hardware designed for video games turned out to be hardware for artificial intelligence. Nobody planned that. The problems happened to match.

Now the memory, where the reason is completely different.

The GPU does not read the file once and remember it. Every single word a model produces requires reading through the entire set of numbers again. That is not occasional access. It is a constant, enormous flow, repeated for every word on the screen.

VRAM sits physically on the card, a short distance from the GPU, connected by something very wide. RAM sits elsewhere in the machine, further away, connected by something much narrower. Both hold things while they are being worked on. Only one of them can deliver at the rate this particular job demands. When the connection cannot keep up, the result is a GPU with enormous computing power sitting idle, waiting for numbers to arrive (APXML, n.d.).

This explains the thing that surprises people who try to run a model on a machine that is slightly too small. It often starts anyway. When a file will not fit in VRAM, some of it can be left in RAM and fetched as needed, an arrangement the card can technically manage (BentoML, 2026). What it produces is not a small penalty. It is somewhere between five and thirty times slower, which in practice means a person asks a question and gives up before the answer finishes (CORSAIR, 2026).

The reverse is also true and is worth knowing. Once a file has been loaded into VRAM and fits there, the narrow connection to the rest of the machine stops mattering almost entirely, because nothing needs to cross it anymore (Glukhov, 2025). The whole job is happening on the card.

So the two answers are these. There are two processors because some work has a queue in it and some does not. There are two memories because the card can only run at full speed on numbers it can reach without leaving home.

Storage sits underneath both and answers a third question, which is where things live when nobody is using them. It is the largest of the three and by far the slowest, and nothing is ever computed there. A file on storage is a file waiting.

Which is why the number that decides everything is VRAM. Not because larger is better in some general sense, but because fitting and not fitting are two different machines. Below the line the work happens on the card at full speed. Above it, the card waits.

A Chromebook has one processor and one memory. Neither of them is the wrong quality. They are the wrong kind, for this one job, and they are perfectly good for every other job the machine was sold to do.

References

APXML. (n.d.). LLM memory bandwidth importance. https://apxml.com/courses/llm-model-sizes-hardware/chapter-3-model-size-hardware-connection/memory-bandwidth

BentoML. (2026, April 15). What is GPU memory and why it matters for LLM inference. https://www.bentoml.com/blog/what-is-gpu-memory-and-why-it-matters-for-llm-inference

CORSAIR. (2026, April 28). Memory for local LLMs: How much RAM do you need? (and when speed matters). https://www.corsair.com/us/en/explorer/diy-builder/how-tos/memory-for-local-llms-how-much-ram-do-you-need-and-when-speed-matters/

Glukhov, R. (2025, June 12). LLM performance and PCIe lanes: Key considerations. Medium. https://medium.com/@rosgluk/llm-performance-and-pcie-lanes-key-considerations-db789241367d

The diagrams · 1 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

Inside the machine — RAM and CPU on the machine side, VRAM and GPU on the card, storage underneath both.

On the formthe first diagram

A machine has two of each, and the reason is that holding something and working on something are two different jobs.

Read the picture across, not down. The top row is the two places a file can sit while it is being used. The bottom row is the two things that can do the arithmetic. The left column is in the machine itself. The right column is on the card.

Storage runs underneath both columns because it belongs to neither. Nothing is ever worked on in storage. A file there is a file waiting.

The words in the boxes are the words you will see on a spec sheet, in a store, and in every guide about this you ever read.

The diagrams · 2 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

At rest and in use — the same file drawn in storage, then a copy in VRAM. Same file, two addresses. One of them forgets.

On the formthe second diagram

This is one machine drawn twice, at two different moments.

On the left the file is in storage. It will survive the power going off, the machine sitting in a drawer, and a year passing. Nothing is happening to it.

On the right the same file is in VRAM. Now it can be worked on. It also disappears completely the instant the power is cut, and it has to be put there again the next time.

There is deliberately no arrow between the two halves, because nothing travelled. Both pictures are true of the same machine at different times. The file did not go on a journey. It changed address.

The diagrams · 3 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

What the word load sounds like, beside what the machine actually does. The left panel is drawn wrong on purpose.

On the formthe load misconception diagram

Two pictures of the same machine.

The picture on the left is deliberately wrong. It shows what the word load sounds like: an arrow carries the file up out of storage into VRAM, and there is a dashed outline where the file used to be.

The picture on the right is what actually happens. The file stays in storage, at full strength. A copy of it appears in VRAM. Two addresses, one file, and one of them forgets when the power goes off.

Load means copy, not move. Placed here on purpose, in grey and dashed, so the correct picture beside it has something to be correct against.

The diagrams · 4 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

Will it fit? Panel 1 of the ladder — Chromebook, 4 GB RAM against a 6.63 GB file.

On the formbuilds up to the third diagram

Every bar is drawn to the same scale, and the red block is the same file every time. That is what makes the four comparisons honest.

The question is the same for each machine and it is answered with subtraction. Is the number on the machine larger than 6.63, or is it not.

The first bar is different from the other three, and the difference matters. The Chromebook’s bar is RAM, the working memory in the machine itself. The other three bars are VRAM, working memory on a card. The Chromebook does not have a small card. It has no card at all, which is why its RAM is the only thing that could possibly hold the file, and why it comes up short by 2.63 gigabytes.

Notice what the question never needed. Not the speed of the machine, not the year it was made, not the price. One subtraction settled all four.

Three machines in the world can hold this file. None of them is in this room.

The diagrams · 5 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

Will it fit? Panel 2 — RTX 4060, 8 GB VRAM.

On the formbuilds up to the third diagram

Every bar is drawn to the same scale, and the red block is the same file every time. That is what makes the four comparisons honest.

The question is the same for each machine and it is answered with subtraction. Is the number on the machine larger than 6.63, or is it not.

Notice what the question never needed. Not the speed of the machine, not the year it was made, not the price. One subtraction settled all four.

Three machines in the world can hold this file. None of them is in this room.

The diagrams · 6 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

Will it fit? Panel 3 — RTX 5070 Ti, 16 GB VRAM.

On the formbuilds up to the third diagram

Every bar is drawn to the same scale, and the red block is the same file every time. That is what makes the four comparisons honest.

The question is the same for each machine and it is answered with subtraction. Is the number on the machine larger than 6.63, or is it not.

Notice what the question never needed. Not the speed of the machine, not the year it was made, not the price. One subtraction settled all four.

Three machines in the world can hold this file. None of them is in this room.

The diagrams · 7 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

Will it fit? Panel 4 — RTX 4090, 24 GB VRAM.

On the formbuilds up to the third diagram

Every bar is drawn to the same scale, and the red block is the same file every time. That is what makes the four comparisons honest.

The question is the same for each machine and it is answered with subtraction. Is the number on the machine larger than 6.63, or is it not.

Notice what the question never needed. Not the speed of the machine, not the year it was made, not the price. One subtraction settled all four.

Three machines in the world can hold this file. None of them is in this room.

The diagrams · 8 of 8

The words, in plain terms

storage

Where things stay when the power is off.

Turn the machine off, come back in a year, your photos are still there. That is storage doing its job.

In a gameThe install size. A 90 GB game has to fit on the drive before you can play it.

32 GB in total. Two to four were free on the twelve we checked.

memory (RAM)

RAM — random access memory

Where work happens while it is happening.

Nothing can be worked on in storage. It has to be moved here first, and this empties completely every time the power goes off.

In a gameThe “8 GB RAM minimum” line in system requirements — what holds the game while it runs.

A Chromebook has 4 GB.

processor (CPU)

CPU — central processing unit

The part that does the arithmetic.

A few things at a time, very quickly, in order. That turns out to be the wrong shape for this job.

In a gameThe other line in system requirements. It runs the rules of the game.

the card (GPU and VRAM)

GPU — graphics processing unit · VRAM — video random access memory

A second processor with memory of its own, built to do a million small sums at once.

It was built to colour the pixels in a video game. Nobody designed it for AI; it just happens to be the same shape of problem.

In a gameThe graphics card. VRAM is what decides the texture setting you can run without stuttering.

Cards come with 8, 16 or 24 GB of VRAM.

The ladder — all four machines together, with verdicts. This is the panel students copy.

On the formthe third diagram

Every bar is drawn to the same scale, and the red block is the same file every time. That is what makes the four comparisons honest.

The question is the same for each machine and it is answered with subtraction. Is the number on the machine larger than 6.63, or is it not.

Notice what the question never needed. Not the speed of the machine, not the year it was made, not the price. One subtraction settled all four.

Three machines in the world can hold this file. None of them is in this room.

View

The classwork

Could this class run its own AI? Day 1 of 6. Section 1 goes with the reading on your screen. Section 2 goes with the diagrams. Answer the required items first. If you finish those, keep going. Station view is read-only — it is the backup for a form that will not load. Switch back to My view to answer for a grade.

Question 1multiple choice

Which period are you in?

APeriod 1
BPeriod 2
CPeriod 4

Question 2multiple choice

According to the reading, why does a machine built for this work carry two processors?

ABecause one of them is a backup in case the other fails
BBecause some work has steps that wait on each other and some does not
CBecause a GPU cannot do anything a CPU can do
DBecause the machine runs two programs at the same time

Question 3multiple choice

What does the reading say a CPU is shaped for?

AWork where the second step needs the answer from the first
BWork that can all happen at the same instant
CHolding files when the power is off
DProducing images on a screen

Question 4multiple choice

The reading says a GPU has thousands of lanes, each slower than a CPU lane. When is that arrangement useless?

AWhen the work involves large numbers
BWhen the machine is old
CWhen the work has a queue in it and each step waits on the one before
DWhen there is not enough storage

Question 5multiple choice

How often does the GPU read through the whole set of numbers in the file?

AOnce, when the file is first loaded
BOnce per sentence
COnce for every single word it produces
DOnly when the answer is long

Question 6multiple choice

Why is VRAM able to keep up with that demand when RAM is not?

AVRAM is a newer invention than RAM
BVRAM sits on the card, close to the GPU, on a much wider connection
CVRAM holds more than RAM in every machine
DRAM empties when the power goes off and VRAM does not

Question 7multiple choice

The reading describes what happens when a file is slightly too large for VRAM. What does it say?

AThe machine refuses to start and shows an error
BPart of the file stays in RAM and gets fetched as needed, which is five to thirty times slower
CThe file is automatically made smaller
DThe GPU shuts off and the CPU takes over at full speed

Question 8multiple choice

Once a file fits in VRAM, what happens to the importance of the connection between the card and the rest of the machine?

AIt becomes more important
BIt stops mattering almost entirely, because nothing needs to cross it
CIt stays exactly as important as before
DThe reading does not say

Question 9multiple choice

Why does the reading say nothing is ever computed on storage?

AStorage is where things live when nobody is using them
BStorage is broken on most machines
CStorage is only for photos and music
DStorage is faster than VRAM but harder to reach

Question 10multiple choice

The reading says a Chromebook’s processor and memory are not the wrong quality. What is it about them?

AThey are too old to be useful for anything
BThey are the wrong kind for this one job, and fine for everything else
CThey are the right kind but there is not enough of either
DThey were installed incorrectly at the factory

Question 11multiple choice

Which sentence best states the reading’s main point?

ANewer computers are better than older computers
BFitting and not fitting are two different machines, not two speeds
CA GPU is a faster version of a CPU
DEvery computer can run a model if you wait long enough

Question 12written

The reading gives two different reasons for the two kinds of duplication. Explain both in your own words: why there are two processors, and why there are two kinds of working memory. Make it clear that the reasons are not the same.

Paragraph.

Question 13written

Someone tells you their computer is very fast, so it must be able to run this file. Using the reading, explain what they have gotten wrong and what they should be looking at instead.

Paragraph.

Question 14multiple choice

On the first diagram, which two things sit on the card?

ARAM and CPU
BVRAM and GPU
CStorage and RAM
DStorage and GPU

Question 15multiple choice

On the first diagram, storage is drawn underneath both sides rather than inside either one. Why?

AStorage is physically larger than the other parts
BNothing is ever worked on in storage, so it belongs to neither side
CStorage is optional on most machines
DThe diagram ran out of room

Question 16written

On the second diagram, the same file is drawn twice in the same machine. Name the two places it is drawn. Help: Use the words from the diagram.

Short answer.

Question 17written

The second diagram has no arrow between its two halves. Explain why an arrow would give the wrong idea about what is happening.

Paragraph.

Question 18multiple choiceoptional

On the third diagram, the Chromebook bar is labelled RAM and the other three bars are labelled VRAM. What does that difference tell you?

AThe Chromebook’s RAM is a small version of VRAM
BThe Chromebook has no card at all, so its RAM is the only thing that could hold the file
CVRAM and RAM are two words for the same thing
DThe Chromebook’s card is too old to be listed

Question 19writtenoptional

On the third diagram, how much of the file has nowhere to go on the Chromebook? Help: The number is printed on the diagram.

Short answer.

Question 20writtenoptional

A student says the third diagram proves the Chromebook is a bad computer. Using the diagrams and the reading, say whether you agree and why.

Paragraph.

The first item is your name. Answer it — that is what puts you on the work now that email collection is off.

Exit ticket · on your own