Σάββατο, Ιουλίου 02, 2005

TFT + CRT desktop

This has been debated a million times. Everyone (and their dog) knows the absolute truth about TFT and CRT and has a very clear opinion that can usually be summarized as "TFT is teh r0x0rz" or "TFT is teh sux0rz".

Since I recently bought a decent 19" TFT I have been amazed by the significant differences that I discovered between these two technologies in various tasks. Take my opinion for what it is, i.e. an opinion, not a bullet-proof double-blind experiment

For the record, the CRT is an excellent flat Nokia 730C with 96KHz sync. It displays 1600x1200 but I usually prefer 1152x864@100Hz. The TFT is an IIyama Prolite E485S 19" (very few reviews of that one in the internet...) that displays 1280x1024@75Hz. It has a DVI connector and it is quite cheap at 390 Euros. For details see this page in ...French (tech stats still readable, of course). It seems that the model has been discontinued and is no longer shown in the UK or US pages. I drive both with a Radeon 9800 Pro.

I'll make my observations into a short list:
  • The TFT fixed resolution is not as restrictive as I thought. Even in non-native modes, like 800x600, the quality is acceptable for games. I assumed that I'd have to use 1280x1024 for everything but that is not the case.
  • This monitor has a 23ms (nominal) response time but in practice, even in very fast games like Quake 3 or UT2004 I was not bothered much. I could use a snappier response, but I had no trouble playing Q3 at "hardcore" levels. For strategy, RPG and other less intensive games the screen is fine.
  • The refresh rate does matter, although you don't need 120Hz to get a steady image with a TFT. 60Hz does flicker a little on the TFT and I routinely choose 75Hz.
  • The analog output is obviously degraded when I use both screens at the same time. This makes the CRT look hazy. I suppose there is a point in buying "high-end" (as in Matrox, for example) graphics cards for multi-CRT work.
  • I did not see a huge difference moving my TFT from analog to DVI. It's probably better but not by much. Your mileage may vary depending on the quality of your graphics card (DAC) and the quality of the TFT's digitization circuits (ADC).
  • The TFT color is simply not as good as the CRT. The Nokia has a very good color performance and side-to-side comparison running two copies of the same movie reveals huge differences. I used to think that the color performance of the TFT was really good, until I saw the same movie scene side by side. The only way to get a good color range with the TFT is to use insane levels of brightness. When both monitors are adjusted to the same brightness levels that don't make my eyes hurt the range of the TFT is limited. Most importantly, black is not really ... black. It looks more like dark green. On the other hand, the color is quite homogeneous and the contrast is strong and appropriate for text and office use. I have configured the TFT at 24% brightness and 36% contrast. More expensive TFTs may be better at this, but I cannot afford them right now!!
  • Subpixel antialiasing for fonts is a controversial issue. Some fonts are markedly improved, others are degraded. I suppose that the font design should be taken into account. Admittedly, the Windows fonts are quite good with subpixel antialiasing (Microsoft calls this "ClearType") and most users are right in preferring them. The Linux/X/freetype algorithm is also very good and provides excellent results with some fonts.
  • I have noticed one faulty subpixel in my screen. Luckily, it is at the right boundary and I never see it in ordinary conditions. For those that want a precise test, this page can help (and, no, you don't have to pay anything)!

I'm quite happy with my new monitor, but the TFT technology must certainly be improved. Unfortunately, the response time has become a major selling point, even though the majority of users really won't notice the difference between 25ms and 8ms for everyday tasks. I'd rather have excellent color instead. From a marketing perspective, excellent color is not something you can easily quantify, while the 8 vs 12 vs 16 ms response time is something that even the most naive user can grasp.


Τρίτη, Ιουνίου 28, 2005

Oh, the irony... Creationism ads in my blog!

I just noticed that Google displays advertisements which promote the "Intelligent Design" concept in my sidebar. Actually, I did put the Adsense code in the sidebar, but this was not what I anticipated. I guess that my recent (?) post regarding Evolution was relevant enough.

Well, I certainly don't expect any of my readers to be clicking any of these ads, so I'll probably remain a poor Ph.D. candidate. I think you should click them and see why "Intelligent Design" is an unbelievably bad idea. I can assure you that the sites linked to them are genuine fun for anyone with a basic understanding of the scientific method.

I had briefly quoted Karl Popper in my aforementioned post and I need to repeat his proposition that any existential statement ("there exists a X that does Y") is verifiable but not falsifiable and therefore is clearly metaphysical (it cannot be corroborated by experience). As such, any statement of the form "evolution was done by X" is clearly not scientific. It may be true, but we may possibly never know. And it isn't science.

I spent quite some time reading Popper's excellent "The logic of scientific discovery since my last post. I picked it up in Edinburgh, where I was visiting a friend (greetz to my 733t friend hax0r, vvas). It illuminates the methodology of science in a way that makes Popper's propositions immediately compelling. It's one of these books that seems obvious once you understand what it says. Truly, the work of a genius.

I'll spend the following few minutes disproving one of the ridiculous claims that I read in one of the advertised "intelligent design" sites. These people claim that natural selection fails to explain the concept of "return to normalcy", according to which talented people may not breed to even more talented children, although inversely, average people may give birth to talented children. First error: Natural selection can not be disproved by individual examples. Natural selection explains the evolution of a species, not the evolution inside a specific genealogical tree. Second error: the concept of "return to normalcy" is a probabilistic concept. The selection of paternal and maternal genes is a random process and a child usually does not get all the good genes that his father or mother have to offer. As a result, a child usually falls in between his parents for most quantitative attributes. As a crude example, if father has Genius_gene_A and Average_gene_B and mother has Genius_gene_C and Average_gene_D, 25% of their offspring will be pure genius, 50% will be like their parents (1 Genius and 1 average gene) and 25% will be pure average. The expansion of these "combinations" when more genes are implicated gives rise to the so-called binomial distribution. On average, most children will be similar to their parents and usually between them. Out of sheer luck (?), gifted children can be born from average parents, without the need to invoke "divine intervention". Similarly, gifted parents may have average children.


P.S. I just noticed that the creationism ads are gone! Oh, well...

Δευτέρα, Ιουνίου 27, 2005

Stopping coffee

I usually don't wish to talk about myself in this page. I prefer to present things that I consider interesting. In this case, however, I'll make a small exception, in the hope that my experiences will be of value to some of you.

During the last year I increased my caffeine intake considerably. I was serving in the army and I had to wake up at 05:50 - 06:30 or stay up during the night. Caffeine did help. Besides the actual pharmacological effect--which may gradually diminish--the enjoyment of small pleasures, like coffee, is sometimes psychologically indispensable. Now that I enjoy considerable working freedom (being a Ph.D candidate can be beneficial for your sleep habits, especially if you prefer staying up late instead of waking up early) I decided to gradually reduce my caffeine consumption.

(you may safely skip the following 4 paragraphs if you have no interest whatsoever in the biological properties of caffeine and similar molecules)

The caffeine molecule is a methylated purine that bears some relation to DNA bases and energy storage molecules like ATP. The broad class of methylated xanthines (kind of purine) includes several variants that can be found in natural (and not-so-natural) sources.

It is a lesser known, but true, fact that caffeine renders cells sensitive to DNA damage, especially from ionizing radiation (see here and here, for example). This is usually of interest in cancer radiotherapy, but the effect also occurs in normal cells. This raises the question of whether caffeine increases the susceptibility of normal cells to DNA damage, mutations and cancer. Fortunately, there is absolutely no indication to support this idea. Surprisingly, some studies even indicate that caffeine may decrease cancer risk in healthy individuals.

On the other hand, increased caffeine intake does increase fat metabolism and reduce appetite and may help during weight loss. It also improves athletic performance, which is why it is a controlled substance (high levels in athletes are considered "doping"). The relevant bibliography is very, very confusing because many "weight-loss" drug companies sponsor studies of dubious quality that get published in low-impact journals (impact factor is a rough measure of the credibility of a journal, as evidenced by the number of publications that refer to this journal). As a general rule, increased caffeine intake cannot be routinely recommended as a way to promote weight loss because of significant side-effects, although it might work for some people. The exact mechanism is not entirely clear at this moment.

Finally, another, significant effect of caffeine ingestion is the induction of anxiety. Caffeine consumption over 200mg/d can be a major cause of anxiety for some people and should be evaluated in all people that present with symptoms related to anxiety.

All the above being said, I must admit that I enjoy a good cup of coffee and I don't consider this to be particularly bad for health (in moderation, of course). I usually drink high quality espresso that I prepare at home with a nice Krups espresso machine. Its caffeine content, when prepared with Arabica coffee is quite low and the flavor is excellent. As a side note, I don't like complicated hot-drinks based on coffee (double extra latte frappuccino with whipped cream is nice, but it isn't coffee by my definition.)

Anyway, I decided to reduce my daily double espresso ritual to 2-3 espresso shots per week. At first I had a constant headache, especially at the back of my head. This was quite annoying but not strong enough to make me want an aspirin or paracetamol. The other weird effect was the deregulation of my sleep hours. I didn't sleep more, I just slept at odd hours. I could fall asleep at 16:00, wake up at 20:30 and then sleep again at 05:00. It seems that my insistence on drinking coffee strictly in the morning had conditioned my brain to accept this as "wake-up time".

A few days later, my headache is gone and my sleep is generally back to schedule. Most importantly, I can get up almost at any time with very little difficulty. Waking up is much more painless now that I don't need coffee to get me going. I simply open my eyes, stand up and I am completely awake and ready. My athletic performance has dropped a little bit (~5-8%) judging by my average cycling speed, but it's hard to provide an accurate estimate because the wind and the ambient temperature vary a lot these days. Not that it matters much, since I don't really compete with anyone. (and, of course, I can always drink coffee if I feel the need for speed).


European software patents

It should come as no surprise that the process for the adoption of US-style software patents in Europe is progressing. There is considerable lobbying from major software companies to that effect.

I am not a lawyer and I cannot provide a reliable analysis of the proposed framework. However, I do know that several open source and free software efforts are threatened by patent laws. This is an important problem.

My experience in the Biomedical sciences shows that in the long term the zealous patent holders only serve to aggravate the problem by inflating the costs of research. The end result is that every respectable lab or university tries to acquire patents in order to economically survive and afford the (patent-encumbered) expensive research materials. Repeat this process and see where it leads...

In my mind, the advancement of human knowledge and the benefit of society at large take precedence over individual or corporate rights and benefits. I'd rather have some companies (or even individuals) temporarily deprived of their rightful privilege to patent intellectual property than allow the premature adoption of an ill-formed directive that puts science and free software at risk. Patent holders can wait until a good solution has been found.

For that reason, I think that the current EU patent proposition should be re-evaluated. I understand that the EU does need a central patent mechanism. I understand that the current system is inadequate. However, I'm not convinced that the proposed directive is a satisfactory solution.

I urge my EU readers (not that I have many readers, but anyway...) to consider the matter carefully and act accordingly.

Many details can be found in the excellent Europa site. This page contains lots of related information.

Also click this link for some (admittedly biased) information.