--- title: "What the specs mean" subtitle: "Inside a computer · Specs and speed · Lesson 1" --- # What the specs mean **Name:** {{field-24}} **Date:** {{field-15}} **Class:** {{field-15}} > **Key question:** Your phone has "256 GB" and "8 GB" on its box. Which one decides how many apps stay open? :::teacher-note **In one sentence:** Students open what each row of a spec sheet measures (processor, RAM, storage, network, graphics), compare a phone, a laptop and a server, and set a spec sheet to match an advert (AC9TDI8K01 node 1). **Students should be able to say:** I can name the main specs on a spec sheet. I can say what each spec measures, in plain words. I can explain why a phone, a laptop and a server have different specs. **Width:** the unmarked parts are the floor every student does (predict, run, investigate and make). Typical adds the modify practice; wider adds the real-world contexts. They add contexts, not difficulty. Students work in the online tutorial alongside this sheet. ::: ## Predict :::keep-together **A laptop slows down when you have 40 browser tabs open. Which spec is most about how much it can work on at the same time?** ☐ Processor speed (GHz) ☐ Network (Mb/s) ☐ RAM (GB) ☐ Storage size (GB) My prediction, and why: {{lines-3}} ::: :::teacher-note **What happens:** RAM: it holds everything the computer is working on right now. Storage is what it keeps; the processor is how fast it works. ::: ## Run Try it on the board in the tutorial. Was your prediction right? What was different? {{lines-2}} ## Worked example: reading a spec sheet :::keep-together ### One line at a time 1. $\text{8-core 3.0 GHz processor}$ — 8 cores work on 8 things at once; each takes 3 billion steps a second. 2. $\text{16 GB RAM}$ — The working space: running apps and open files. It empties when the power goes off. 3. $\text{512 GB SSD}$ — Storage: keeps 512 GB with the power off. SSD is the fast type; HDD is slower. 4. $\text{Wi-Fi, 300 Mb/s}$ — Network bandwidth: 300 million bits can arrive each second. 5. $\text{built-in graphics}$ — No separate graphics card: the processor's own graphics. Now name the spec on a phone box. **A phone box says **256 GB**. Which spec is that, most likely?** ☐ Storage: how much it can keep ☐ Network speed ☐ RAM: how much it can work on at once ☐ Processor speed ::: :::teacher-note **Answer:** Storage: how much it can keep Storage. Phone RAM is much smaller, usually 4 to 16 GB. ::: :::keep-together ### Find the mistake **Sam reads a phone's spec sheet. Click the line where it first goes wrong.** ``` 1 The phone's spec sheet says 8 GB RAM and 256 GB storage. 2 RAM and storage are both memory, so the phone has 264 GB of memory. 3 So it can have 264 GB of apps running at once. 4 That is why it never slows down. ``` Line: {{field-15}} Why is it wrong? {{lines-2}} ::: :::teacher-note **Answer:** line 2 Line 2: RAM and storage are different parts that measure different things. 8 GB of RAM is the working space; 256 GB of storage is what it keeps. ::: :::keep-together ### Units **Which unit measures how fast data arrives over a network?** ☐ GHz (gigahertz) ☐ GB (gigabytes) ☐ Cores ☐ Mb/s (megabits a second) ::: :::teacher-note **Answer:** Mb/s (megabits a second) Bandwidth is measured in bits a second: Mb/s or Gb/s. ::: :::typical ## Vary: phone, laptop, server **The phone.** **The laptop.** **The server.** **Graphics.** Work in the tutorial. Plan first: what will you change, and how will you test it? {{box-4}} ::: ## Sort the specs :::keep-together ### Sort **Which part does each spec describe?** Groups: Processor, RAM, Storage, Network - 3.2 GHz: {{field-15}} - 6 cores: {{field-15}} - 16 GB, empties when switched off: {{field-15}} - 1 TB SSD: {{field-15}} - 2 TB hard disk (HDD): {{field-15}} - Wi-Fi 6, up to 600 Mb/s: {{field-15}} ::: :::teacher-note **Answer:** 3.2 GHz → Processor; 6 cores → Processor; 16 GB, empties when switched off → RAM; 1 TB SSD → Storage; 2 TB hard disk (HDD) → Storage; Wi-Fi 6, up to 600 Mb/s → Network GHz and cores: processor. Working space: RAM. SSD and HDD: storage. Mb/s: network. ::: :::keep-together ### Storage full **Your phone says "Storage full". Which part has run out?** ☐ Storage ☐ RAM ☐ Network ☐ Processor ::: :::teacher-note **Answer:** Storage Storage holds your photos and apps. Deleting things frees it. ::: :::keep-together ### Review: bits **Review: how many different patterns can 8 bits make?** ☐ 8 ☐ 16 ☐ 255 ☐ 256 ::: :::teacher-note **Answer:** 256 2⁸ = 256 patterns, 0 to 255. ::: ## Make: build it from an advert Then: find the spec sheet of your own phone or laptop (Settings › About). Which numbers are RAM and which are storage? Work in the tutorial. Plan first: what will you change, and how will you test it? {{box-4}} ## Exit ticket :::keep-together **Name three specs and say what each one measures.** {{lines-3}} ::: :::teacher-note **Answer:** For example: RAM, how much it can work on at once; storage, how much it keeps with the power off; processor GHz, how fast each core works; network Mb/s, how fast data arrives. :::