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On the cost of converting ASCII to UTF-16
From Daniel Lemire's Blog

On the cost of converting ASCII to UTF-16

Many programming languages like Java, JavaScript and C# represent strings using UTF-16 by default. In UTF-16, each ‘character’ uses 16 bits. To represent all 1Continue...

Science and Technology links (February 6th 2021)
From Daniel Lemire's Blog

Science and Technology links (February 6th 2021)

You can use artificial intelligence and satellite images to count the number of elphants found in the wild. It appears that a billion people on Earth now use an...

Number Parsing at a Gigabyte per Second
From Daniel Lemire's Blog

Number Parsing at a Gigabyte per Second

Computers typically rely on binary floating-point numbers. Most often they span 64 bits or 32 bits. Many programming languages call them double and float. JavaScript...

Science and Technology links (January 24th 2021)
From Daniel Lemire's Blog

Science and Technology links (January 24th 2021)

Year 2020 was great for PC makers. We are selling more and more PCs. Reportedly, Sony sold 3.4 million PlayStation 5 in only four weeks, a record. The demand for...

Science and Technology links (January 16th 2021)
From Daniel Lemire's Blog

Science and Technology links (January 16th 2021)

You can tell people’s political affiliation by image recognition technology. There are far fewer stars and galaxies than we thought. The universe is relativelyContinue...

Science and Technologie links (January 9th 2021)
From Daniel Lemire's Blog

Science and Technologie links (January 9th 2021)

The Earth is spinning faster and faster: The 28 fastest days on record (since 1960) all occurred in 2020, with Earth completing its revolutions around its axisContinue...

Memory access on the Apple M1 processor
From Daniel Lemire's Blog

Memory access on the Apple M1 processor

When a program is mostly just accessing memory randomly, a standard cost model is to count the number of distinct random accesses. The general idea is that memory...

Peer-reviewed papers are getting increasingly boring
From Daniel Lemire's Blog

Peer-reviewed papers are getting increasingly boring

The number of researchers and peer-review publications is growing exponentially.  It has been estimated that the number of researchers in the world doubles every...

My Science and Technology review for 2020
From Daniel Lemire's Blog

My Science and Technology review for 2020

The original PlayStation game console (1994) was revolution thanks in part to its CD drive that could read data at an astonishing 0.3 MB/s. In 2020, the PlayStation...

Science and Technology links (December 26th 2020)
From Daniel Lemire's Blog

Science and Technology links (December 26th 2020)

Researchers used a viral vector to manipulate eye cells genetically to improve the vision of human beings. Seemingly independently, researchers have reported significant...

In 2011, I predicted that the iPhone would have 1TB of storage in 2020
From Daniel Lemire's Blog

In 2011, I predicted that the iPhone would have 1TB of storage in 2020

Someone reminded me of a prediction I made in 2011: Your iPhone will have 1TB of storage by 2020, assuming exponential growth, see my plot: http://t.co/iDiT1J7y...

Science and Technology links (December 19th 2020)
From Daniel Lemire's Blog

Science and Technology links (December 19th 2020)

The Flynn effect is the idea that people get smarter over time (generation after generation). The negative effect is the recent observations that people are getting...

Cognitive biases
From Daniel Lemire's Blog

Cognitive biases

One-sided bet: People commonly assume implicitly that their actions may only have good outcomes. For example, increasing the minimum wage in a country may onlyContinue...

Virtual reality… millions but not tens of millions… yet
From Daniel Lemire's Blog

Virtual reality… millions but not tens of millions… yet

In February 2016, I placed a bet against Greg Linden in these terms: within the next three years, starting in March of this year, we would sell at least 10 million...

Converting floating-point numbers to integers while preserving order
From Daniel Lemire's Blog

Converting floating-point numbers to integers while preserving order

Many programming languages have a number type corresponding to the IEEE binary64. In many languages such as Java or C++, it is called a double. A double value uses...

ARM MacBook vs Intel MacBook: a SIMD benchmark
From Daniel Lemire's Blog

ARM MacBook vs Intel MacBook: a SIMD benchmark

In my previous blog post, I compared the performance of my new ARM-based MacBook Pro with my 2017 Intel-based MacBook Pro. I used a number parsing benchmark. In...

ARM MacBook vs Intel MacBook
From Daniel Lemire's Blog

ARM MacBook vs Intel MacBook

Up to yesterday, my laptop was a large 15-inch MacBook Pro. It contains an Intel Kaby Lake processor (3.8 GHz). I just got a brand-new 13-inch 2020 MacBook ProContinue...

Science and Technology (December 5th 2020)
From Daniel Lemire's Blog

Science and Technology (December 5th 2020)

Researchers find that older people can lose weight just as easily as younger people. Google DeepMind claims to have solved the protein folding problem, an important...

Interview by Adam Gordon Bell
From Daniel Lemire's Blog

Interview by Adam Gordon Bell

A few weeks ago, Adam Gordon Bell had me on his podcast. You can listen to it. Here is the abstract: Did you ever meet somebody who seemed a little bit different...

Java Buffer types versus native arrays: which is faster?
From Daniel Lemire's Blog

Java Buffer types versus native arrays: which is faster?

When programming in C, one has to allocate and de-allocate memory by hand. It is an error prone process. In contrast, newer languages like Java often manage their...
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