Two of the several computers I own is the original PowerMac G5 1.8GHz, as well as an AMD 64 3200 home built PC. Both these machines uses two 7200 rpm SATA IDE hard disk drives. I am busy doing an FTP from the Windows machine connected to the G5, retrieving a 22GiB file.
Both CPU's are running at approximately 80%, and the network utilization is a constant 18MBps. The interesting thing is that after 3 minutes of copying the PC started making 1 second interval beeps on the internal speaker. This is the thermal warning function built in to the Gigabyte motherboard when the temperature exceeds 70C. The statement I want to make is that the G5's fans are all idling slowly, the system is completely cool and way within spec. I cannot really see any thermal difference to the normal state. Luke warm air is being expelled from the rear fans. However, the AMD is overheating. The hard disk drives are so hot you can boil eggs on them.
The reason? The G5 was designed with thermal considerations in mind from the very beginning. The PC however, received no such attention. You may argue that the G5 costs 5 times as much, but then again PC manufacturers had more than 20 years to get the thermal design of a simple mini tower correct. How difficult can it be to design a case that has good thermal properties? The basic principle is simple - you need to suck in fresh, cool air, let it pass over all hot components internally, and gently blow out the hot air on the other side of the case. This is exactly the same principle used in cooling towers of power plants.
Ever thought it is possible that anything worse than the tax man exists? I found out yesterday that there is one thing lower than lobster excretions, worse than the tax man...
They are commonly known as Estate Agents. Why? Remember I wrote some blog entries ago about having just sold my house through Chas Everitt? Well, since I sold it somewhere in end of November I have heard absolutely nothing from them. They never phoned me - not even once. I only dealt with the lawyers for the transferring of ownership, and as of yet the house is still in my name.
But jumping back to the day I sold the house, the two Chas Everitt estate agents were sitting on my couch in my new place telling me excitedly about the clients they got that made an offer. The offer was R100,000 less than what I wanted, so I was a bit wary. They explained to me that the walls were damp, the cable that sustains the weight that allows my garage door to open and close were completely broken and now the garage door cannot open at all, the place had to be re-painted because the body corporate requested that etc. That was how they negotiated a lower price tag. I fell for that since I really wanted to sell the house - to me it was a liability.
I guess there would be three groups of Java developers out there - those who know about exceptions but have never heard of checked and unchecked exceptions, those who know what it is but do not understand them and those who truly know and understand them. My educated guess is that most people fall in the former two categories. This article will try and explain the differences between the two kinds of exceptions, as well as when to use which.
In Java the base exception hierarchy as defined in the J2SE API looks as follows:
Serializable ^ | Throwable ^ ^ | | Exception Error ^ | RuntimeException
I think most developers assume that the more years they write code, the better they become. I have a very different measure for whether you are really bettering yourself.
Ask yourself this, and answer honestly:
With every new project you successfully complete, do you feel that the previous project was not done as good as the one just finished? Do you have an urge to open that previous project and bring it to the same standards as the latest project? Or do you feel that both projects have been created equally?
Everybody knows that SPAM caused the IT industry to respond with content filtering techniques and SPAM blocking techniques to help control this useless waste of bandwidth and irritation factor.
Same with large files. Bored employees are sending lots of 1MB+ mails containing the latest movie or powerpoint presentation of some joke. This obviously does not help the IT budget. So they either block certain content such as MPEG files or park them for late delivery.
What about employees visiting non-work related web sites? Surfing non-business related web sites wastes available bandwidth for important business related work. So IT departments block access to sites not deemed work related. And here I started discovering the first encounter what I now call "IT paranoia". At a large company I sometimes consult for, which houses easily a hundered developers - many of which write code in Java, I once tried to browse for information on one of the well known java sites. Their proxy server denied me access because it was non-business related. This impeded quite a bit on my productivity.