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Why can’t we just stick RAM directly onto the CPU?

22 April 2025

In the world of computer science, speed is everything. So, it’s easy to see why the idea of sticking RAM directly onto the CPU seems like a genius move. Zero latency, lightning-fast speeds, and no more bottlenecks—what’s not to love? But in reality, it’s not that simple. Let’s break down why we can’t just combine these two crucial components into one.

The difference between CPU and RAM

At first glance, sticking RAM onto the CPU might sound like a great way to boost performance. After all, the closer RAM is to the CPU, the faster data can be accessed, right? Unfortunately, it’s not that straightforward. The CPU and RAM are built in fundamentally different ways.

CPUs are designed to handle calculations at breakneck speeds using logic processes. On the other hand, RAM—specifically Dynamic RAM (DRAM)—uses capacitors to temporarily store data. The catch is that these capacitors need constant refreshing to retain their information. This is similar to a student frantically rereading their notes to ensure they remember everything during revision.

Why it doesn’t work together

Trying to combine CPU and DRAM onto the same chip would cause chaos in the manufacturing process. DRAM fabrication doesn’t align well with the processes used to create a CPU. Imagine trying to install a high-end GPU into a budget laptop—it just won’t fit, and forcing it could cause damage.

Even cutting-edge technologies like Intel’s Haswell architecture use embedded DRAM (eDRAM) sparingly. The goal is to use just enough to boost performance without massively increasing production costs. However, merging CPU and RAM completely would be a manufacturing nightmare.

The speed factor: DRAM vs. SRAM

Even if we could combine the two, there’s another issue: speed. DRAM operates at a top speed of about 1 GHz, while modern CPUs can easily surpass 3 GHz. That’s like putting bicycle tyres on a Formula 1 car—you’re limiting the performance of the entire system.

To overcome this speed gap, CPUs use SRAM (Static RAM) for on-chip cache. SRAM is much faster than DRAM but comes with its own drawbacks: it’s bulkier and significantly more expensive. Sure, we could fill a CPU with SRAM, but that would come at an astronomical cost—far more than most of us are willing to pay.

Why we stick to separate RAM and CPUs

While combining RAM and the CPU might sound like a performance dream, the technical and cost limitations make it impractical. The current balance of DRAM for main memory and SRAM for cache strikes the best compromise between speed, cost, and practicality.

Want to know more? Check out The Lesson Hacker’s YouTube video – 

For more Lesson Hacker Videos, check out the CraignDave YouTube playlist HERE.

Visit our website to explore more cutting-edge tech-transforming news in the computer science world!

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Getting maximum value from Smart Revise with Year 11

15 April 2025

Exams are only a few months away and what your students do now is going to make the biggest impact to their results in August. It almost doesn’t matter what their work ethic has been like up until now, there is still time for all students to achieve their potential if they engage in regular active revision using the best techniques from today. 

Once you have delivered all the course content switch the topic filters to “Student controlled” in Smart Revise. Make sure you have Quiz, Terms reflective, Terms interactive and Advance modes enabled in the class settings. This will allow the students to take charge of what to revise, when and how. 

Top tips for students 

  • Use the Summary report to know the topics that are your strengths and weaknesses. 
  • Click on a Quiz pie chart in the summary report to do multiple-choice questions only on weaker topics. 
  • Look at the Top 10 revision references at the bottom of the summary report.
    These are your specific weaknesses across the whole course. You can watch the Craig’n’Dave videos if that helps but beware of passive revision. 
  • Click on a Terms pie chart in the summary report and filter the cards you want to focus on: sad, neutral, happy, unanswered. Reflective is a passive reflection. Interactive is more challenging but is essential. You should be able to define terms at this stage of the course. Use reflective as a reminder and interactive when you are revising. 
  • Click on an Advance pie chart in the summary report to see exam-style questions. Use the next button to find a question you want to attempt. Start with the low mark questions first and work up. Pretend you are in a real exam. Set an alarm on your phone for the number of marks the question is worth and spend that amount of time answering the question. 
  • Use the built-in mark schemes to mark your answer and be realistic. It doesn’t matter if you get low marks when you are practicing. 
  • If you don’t get full marks, note the question number. Have another go at the same question a few days later to see if you can improve your answer. Use the “last answer” button to see your most recent answer. 
  • Start with low mark questions, but don’t avoid the high mark Advance questions forever. You will get lots of 1–6-mark questions in your exam and one 8-mark question in each paper. 
  • Just because you know something this week doesn’t mean you will remember it next week so don’t neglect the topics you have mostly green on the pie charts in the summary report. Checking you still have the understanding is important. 
  • Start Terms – Leitner mode is good for daily reminders of terminology once you have mostly green or yellow pie charts in most of the topics on your summary report. Remember to set the topic filters to the whole course before using Leitner mode.
     

Beyond Smart Revise 

Although Smart Revise is great, it is important to provide students with real past papers so they can practice writing on lines with a pen too! Some papers will be publicly available on exam board websites, but others will require logging in to their portals to be downloaded. 

We often assume students will just “know” how to revise without being explicitly taught how to. This is a mistake. Show students the technique of mind mapping and build a mind map for a topic with them, maybe using the Terms in Smart Revise for reference. Smart Revise compliments this tried and tested approach, it does not replace it. 

One technique we developed with our students is the “what why web” (see what we did there) which is a scaffolded approach to making a mind map. Write the concept in the middle and then on a second branch state what words are associated with the concept, and on a third branch state why it is necessary, any implications and examples. 

For example, the concept of registers for OCR J277 might look like this: 

As Dunlosky showed, the worst revision students can do is reading their notes, looking over classwork and watching videos because these are passive techniques. Knowledge organisers and revision guides are useful, but they should only be used as a reference guide to check understanding, in themselves they are not revision.

By the way, put those highlighter pens away because research has shown that highlighting notes is worthless!

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Smarter Lessons With Smart Revise Quiz’s: How To Crack The Code

10 December 2024

Why you should start every computer science lesson in years 10 to 13 with Smart Revise Quiz.

Imagine this scenario. You’ve just taught the topic of computer architecture including the purpose of the registers. In class students engaged in answering questions, completed activities and it was a good lesson.

At the start of their next lesson as a recap activity you ask a student in the class, “what was the purpose of the program counter?” The blank face looks back at you. “How can you not know?” you think to yourself, “we only covered this last week.”

Be honest, this happens in your classroom, doesn’t it? The reality is that since your last lesson those students have been bombarded with new information from English, Maths and Science, their short-term memory can only handle so much.

Does it really matter you might ask. After all, when you get to the end of the course you engage in revision and bring all that knowledge back to the fore; but what if there was a better way to learn? What if students could be more confident, more engaged and perform better in tests, mock exams and real exams if they retained more of what you’d taught them over a longer period of time? What if revision at the end of a course benefits the most privileged learners, but does not help the less privileged in the same way? This classic approach to teaching is actually contributing to the gap between advantaged and disadvantaged students.

The better, more successful way

This better way is, “The Revision Revolution” where revision is seen as integral to the learning process. It’s a feature of every lesson. From the very first topic to the very last.

Howell, H, Morrison McGill, R (2022) The Revision Revolution, John Catt.

At its heart revision is about repetition, and the best revision starts early, not at the end of the course. Imagine preparing to run a marathon. Do runners prepare by starting to run 26 miles a few weeks before the event? Of course not. They build up greater distances and stamina over months, if not years of preparation. Running almost every day. Why then should preparing for examinations be any different?

Why not give all students, not just the privileged a better chance of success with an opportunity to recall what they have been learning over and over again in every lesson? Better than that, why not include in that repetition the respected learning theories: spacing, interleaving and personalisation.

It’s pretty obvious. If we don’t regularly recall something we forget it. This is known as the forgetting curve. However, the more we practice, the more we repeat, the more we remember and the more confident we feel.

You might be thinking, “where do I find the time to go back over what I’ve already taught?” The solution is surprising simple. The start of lessons and homework.

Regular recall practice through multiple choice quizzing is in vogue right now and is a key feature in the classrooms of the most successful schools.

The research is clear, regular repetition aids memory retention.

Murre, J., Dros, J. (2015) Replication and Analysis of Ebbinghaus’ Forgetting Curve.


The smarter way

This is where Smart Revise adds significant value. So named because it is a smarter way to revise. Start every lesson with 7 minutes of recall practice with Quiz. It’s low-stakes so it’s easy to get student buy-in. If you have Craig’n’Dave starter activities for GCSE these are good for engagement on entry, but they are for schools who don’t have Smart Revise. Retrieval practice has more impact because it’s based on academic research.

Smart Revise will automatically space questions so that there is an appropriate gap between students seeing the same question again (repetition). It will interleave questions, that is selecting questions from different topics causing the brain to context switch which has a bigger impact on retention. With built-in personalisation questions answered incorrectly are shown again more frequently until the knowledge sticks.

Classic starter activities are one-size-fits-all. Smart Revise provides a differentiated activity for every learner


How to set this up for students

  1. Every time you have finished teaching a topic unlock it for students using the class settings, topic filters. Do not lock the previously taught topics or select a topic you are currently teaching. The number of unlocked topics should increase from one to them all as you progress through the course.
  2. Get students into the habit of entering the classroom, logging on and starting Smart Revise Quiz for themselves at the start of every year 10, 11, 12 and 13 lesson. There is no preparation for the teacher to do.
  3. Spend about 7 minutes on Smart Revise. This is an optimal time. The Quiz will never end, it will just loop questions in a priority queue so that the teacher can stop the activity when they are ready for the main lesson.

Ideally students would also use Smart Revise Quiz for homework too. Aim for 35 questions a week at GCSE (including those done in lessons) and 60 for A level. The flight path on the student’s dashboard will show them if they are on track. Teachers can monitor this with the analytics usage report and see strengths and weaknesses in the question analysis and class matrix reports too.

Students will tell you what the purpose of the program counter is with confidence because Smart Revise will have asked them often enough!

If you’re looking for a smarter way to revise or teach, why not try Smart Revise for FREE? 

Visit Craig’n’Dave’s Smart Revise website to explore all the features.

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