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Why DPI matters: The difference between screen & print quality

8 July 2025

Understanding DPI: What does it actually mean?

DPI (dots per inch) is exactly what it sounds like—it’s a measure of how many tiny dots (or pixels) fit into one inch of space. The more dots you have, the more detail your image retains.

For digital screens, 72 DPI is the standard because it keeps file sizes small and looks crisp at a normal viewing distance. But when it comes to printing, things change dramatically.

Think of it like wearing pyjamas. At home, wearing 72 DPI is fine—relaxed, comfortable, and good enough for what you need. But taking that same look to a first date? Suddenly, the details matter a lot more.

Why does print need 300 dpi (or more)

When you print something, you’re holding it much closer to your eyes than a screen. Your brain expects more detail because it’s used to seeing sharp, high-resolution objects up close. If your image is only 72 DPI, it won’t have enough detail to look crisp—it will appear soft, pixelated, and blurry, like a sun-faded potato chip.

That’s why 300 DPI is the magic number for print. At this resolution, images retain their sharpness even when viewed up close. The higher dot density makes lines and textures look clean, rather than jagged or smudged.

Imagine a giant poster—when viewed from 10 feet away, a few blurry dots don’t matter. But now think about a business card. You hold it right up to your face, and if it’s not printed at high resolution, it’ll look like it was drawn in MS Paint by a four-year-old with a potato.

The simple rule: screen vs print

If you only remember one thing, make it this:

72 DPI is fine for screens. It’s optimised for digital displays, loads quickly, and keeps file sizes manageable.
300 DPI (or higher) is essential for print. It preserves fine details, ensuring your artwork looks as sharp on paper as it does on screen.

What happens if you use the wrong DPI?

If you use 72 DPI for print, your artwork will look blurry and pixelated.
If you use 300 DPI for digital, your file sizes will be unnecessarily large, and it won’t look any better than a 72 DPI image.

So, always think about where your image will be seen before choosing the right DPI. If it’s just for a website or social media, 72 DPI is fine. But if it’s going to a printer, crank it up to 300 DPI to avoid a pixelated disaster.

Want to learn more about getting the best quality out of your designs?

Check out Dave The Lesson Hacker’s YouTube video HERE

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

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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 –