# Re: Article: Increasing the D Compiler Speed by Over 75%

```On Wednesday, 31 July 2013 at 23:26:32 UTC, Walter Bright wrote:
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```On 7/31/2013 3:58 PM, John Colvin wrote:
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It's a quite impressively unbalanced education that provides understanding of memory allocation strategies, hashing and the performance pitfalls of integer
```division, but not something as basic as a speed.
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Have you ever seen those cards that some "electrical engineers" carry around, with the following equations on them:
```
V = I * R
R = V / I
I = V / R

?

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Unbelievable. The author of it writes:

```
"I'm going to explain to you how to use this cheat sheet in case you've never seen this before."
```
http://blog.ricardoarturocabral.com/2010/07/electronic-electrical-cheat-sheets.html

Makes you want to cry.
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Something I discovered during my studies when helping other is that most people to not even try to understand this kind of stuff. They simply brute-force the equation to their memory and regurgitate it as needed without understanding anything. Not because their aren't capable of understanding, simply because they never figured out that equation actually are saying something (and the teaching style often do not help here). They do not relate the equation to actual phenomenon they observe.
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A nice example is the very basic mass times acceleration equals force.
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Granted that acceleration is the variation of speed, this equation means the following :
``` - If you push something it will start to move.
- If you continue pushing it will move faster and faster.
```
- If you do not push, it won't move (or continue moving the way it was).
``` - The heavier it is, the harder it is to move that something.

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Any child knows all the above, it is experienced it in everyday life. And the equation is simply the mathematical notation of this very basic experience.
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If you don't relate such equation to anything real, you'll have all kind of trouble remembering it, knowing when to use it or how to use it.