DirectX 10 marked a radical departure from DirectX 9: In order to be compatible, a graphics processor must feature a unified architecture in which each shader unit is capable of executing pixel-, vertex-, and geometry-shader instructions. The changes in DirectX 11 aren’t quite as fundamental, but they could have just as big an impact—and not only with games.
DirectX 11 is a superset of DirectX 10, so everything in DirectX 10 is included in the new collection of APIs. In addition, DX11 offers several new features and three additional stages to the Direct3D rendering pipeline: the Hull Shader, the Tessellator, and the Domain Shader. And in an effort to deliver cross-hardware support for general-purpose computing on graphics processors, Microsoft has come up with a new Compute Shader.
DirectX 11 will be compatible with both Vista and Windows 7, but many of its graphics features will be available on GPUs designed for previous iterations of Direct3D. Tapping into the Tessellator’s power, however, will require a GPU with transistors dedicated to the task (in this sense, DX11 marks a slight departure from DX10’s vision of a unified architecture). Let’s explore the concept of tessellation now.
When can a file encapsulate more than one type of data? When it’s a metafile, wrapper, or container file. You might think of a container file as a package or envelope in which other files are housed. Zip files, which can contain documents, photos, videos, software programs, and many other types of files, are one type of container that you encounter frequently.
We’ll limit our discussion here to media container formats. A pure container file specifies how the data is stored, but it doesn’t necessarily know how it was compressed or encoded or even what is required to play back those files. This can lead to confusion when dealing with container files wrapped around media because there’s a chance that the media player you’re using is capable of opening the container but not equipped with the algorithm required to decode the files inside. Although a container can theoretically hold any type of data, most are optimized during development to wrap around particular data groups, e.g., digital audio for music; static images for digital photographs; or digital video interleaved with digital audio, plus subtitles, closed-caption information, and chapter data for movies. Container formats that support video also include the information required to synchronize the various data streams in the file during playback.
Conceptually speaking, the Internet can be viewed as consisting of four functional layers: the Link Layer, the Internet Layer, the Transport Layer, and the Application Layer. Each layer has several protocols, sets of rules that define how data is formatted and transmitted, which are known collectively as the Internet Protocol Suite. We’ll discuss all four layers here, but we’ll dive deepest into the Internet Layer and its associated Internet Protocol (IP)—because this is the worldwide network’s most fundamental component.
The Link Layer is the lowest layer and is responsible for delivering data over whatever hardware is in use. A link consists of the physical and logical components that are used to interconnect host computers and other types of network nodes (a node is any electronic device that’s connected to the network, including hosts). Link Layer protocols, including Address Resolution Protocol and Media Access Control, operate only on a host’s link.
Continue reading about Internet Protocol after the jump.
The surge suppressor is one of the unsung heroes of the computer world. Often valued more for its ability to multiply one electrical receptacle into many than for its role as protector of all things electronic, the surge suppressor is your first line of defense against transient power surges that can damage or destroy sensitive components inside your PC. Let’s take a look at how they work.
Before we tackle the concept of surge suppression, we should first understand what exactly a surge is. In the United States, electrical energy flows through standard household wiring at an average rate of 120 volts. Because the system used is alternating current, the voltage level of every AC cycle reaches a peak value that’s roughly 1.414 times higher than 120 volts. A surge occurs when the voltage level suddenly rises significantly higher than that. A lightning strike on a power line, for instance, will cause a transient spike in the electrical power entering your house. Problems with your utility company’s equipment (anything from a downed power line to a defective transformer) can also cause power surges.
Appliances and other electrically powered devices inside your home, however, are much more common causes of power surges. Any device that requires a large amount of energy to switch on or off—examples include refrigerators, vacuum cleaners, and air conditioners—can disrupt the flow of voltage through your home’s electrical wiring. Surges such as these don’t pack as much destructive power as a lightning strike, but they can cause as much damage, instantly or over time.
HDMI (the acronym stands for High-Definition Multimedia Interface) is one of the consumer electronics industry’s more remarkable innovations. This de facto HDTV interface enables the transmission of high-definition digital video, up to eight channels of digital audio, HDCP encryption, the Consumer Electronics Control (CEC) protocol, and five volts of electrical power over a single cable.
HDMI 1.0, introduced in December 2002, had all of these features. The latest version, HDMI 1.3c, boasts several more, including support for Deep Color, auto lip sync, and the two high-definition multichannel audio formats used in Blu-ray discs. Let’s take a look at how HDMI accomplishes all this while remaining backward-compatible with the earlier DVI standard.
Although Windows has included the Program Compatibility Wizard and Compatibility tab to help older programs to run properly under the current version of Windows since Windows XP, these features are not always able to help older applications to run. While Windows 7 continues to offer these features, some editions can also use a better way to run older Windows applications: XP Mode.
Join us after the jump for an in-depth look at XP Mode: the FAQs, what it can do for you, who benefits most from XP Mode, and how to use its new features.
BitTorrent is a tremendously popular peer-to-peer file-sharing protocol designed to simplify and speed up the process of transferring large files over the Internet while drastically limiting the bandwidth consumption of any one server.
In a conventional file-transfer process, a file is stored on a server on a network such as the Internet. Other computers on the network send messages to the server, informing it that they would like to copy that file. When the two sides establish a connection, the other computers become clients to the server. As the number of clients increases, so do the demands on the server. And while each client might consume only a little bandwidth, the server can consume tremendous amounts. To reduce costs and prevent the server from crashing, the server’s owner will typically constrain the speed at which each client is allowed to download data or even limit the number of clients that can be served at one time.
You’re twiddling your thumbs while waiting in the check-out line at your favorite retailer and you hear a great new song over the PA system. You could turn to the next person in line and ask if they know it—engaging in an impromptu but probably fruitless game of Name That Tune—or you could whip out your smartphone, record a snippet of it, and send it to a music-discovery service. It will report back with the name of the song and that of the artist who recorded it, which album it appears on, what year it was released—heck, with a couple of button presses, you can buy the song right then and there.
What technology magic makes such a thing possible? It’s called audio fingerprinting, and it’s gaining significant traction with both music lovers and rights holders looking to protect their assets. There are two basic components to an audio-fingerprinting system: A database containing the unique audio fingerprints of millions of songs, and a tool that can analyze a song and search that database for a match.
Integrated-circuit design is currently based on three fundamental elements: the resistor, the capacitor, and the inductor. A fourth element was described and named in 1971 by Leon Chua, a professor at the University of California, Berkeley’s Electrical Engineering and Computer Sciences Department, but researchers at HP Labs didn’t prove its existence until April 2008. This fourth element—the memristor (short for memory resistor)—has properties that cannot be reproduced through any combination of the other three elements.
Chua first theorized the memristor’s existence based on symmetry. There are four fundamental circuit variables—current, voltage, charge, and flux (changes in voltage), but until now, relationships had been defined for only three of those variables: A resistor opposes the flow of an electric current, so it relates voltage to current; a capacitor stores energy in an electric field between two conductors, so it relates charge to voltage; and an inductor stores energy in a magnetic field created by the electrical current running through it, so it relates flux to current. Chua believed that there must be an element that relates charge to flux, and he dubbed this undiscovered element the memristor because it would “remember” changes in the current passing through it by changing its resistance.
In the past year and a half, solid state drives have come from nowhere to take their place as the Next Big Thing in storage, especially in notebooks. The MacBook Air and the Asus Eee PC and OLPC XO-1 (One Laptop Per Child) netbooks were among the first consumer notebooks to utilize solid state drives. While SSDs are still most popular in netbooks, they have begun appearing in more mainstream notebooks and even high-end desktops.
SSDs have much higher read speeds than traditional drives, and with no moving parts, they’re more durable. They’re not susceptible to magnetic interference or vibration, and they use less power and run much more quietly than standard magnetic hard drives. Best of all, they come in standard 3.5-inch and 2.5-inch formfactors with SATA connectors and emulate traditional drives, so they’re compatible with existing architecture. Unfortunately, they’re also orders of magnitude more expensive per megabyte, thus limiting widespread adoption, at least for now.
Although the fastest solid state drives use DRAM for storage (with a battery backup to preserve data), this White Paper will focus on flash-based SSDs—the variety most commonly found in consumer gear.