BIOS: Technology Means Business

Creative's Sound Blaster Xtreme Fidelity (X-Fi) audio processor is truly a revolution in PC audio. Whether you use headphones, two speakers or multi-channel speakers, your games, movies and music will all be enhanced. Add to this the 109dB SNR audio quality (or 116dB SNR for Sound Blaster X-Fi Elite Pro reviewed here), plus the 136dB SNR internal audio processing quality and THX Certification with the THX Setup Console, and it becomes clear that Creative is on to a winner with the most advanced and priciest Sound Blaster to date.

Pros: Excellent performance; high-quality I/O module and remote
Cons: Pricey; no FireWire or USB 2.0 ports; CMSS-3D is hit-and-miss

Creative's new 7.1-channel audio processor, the X-Fi, is quite simply awesome. Some 24 times more powerful than its predecessor, the Audigy, it brings surround-sound games (no need to compromise audio quality by reducing the number of simultaneous effects) and movies to life, and is great for getting high-quality audio samples onto your computer from an external audio source or instrument.

The new range comprises four PCI-based soundcards: the top-of-the-line Sound Blaster X-Fi Elite Pro (reviewed here), Sound Blaster X-Fi Fatal1ty FPS (£179 inc. VAT), Sound Blaster X-Fi Platinum (£149 inc. VAT), and the Sound Blaster X-Fi Xtreme Music (£99.99 inc. VAT). All models share the same core processor and have common features, such as CMSS- 3D (Creative Multi-Speaker Surround), 3DMIDI and EAX 5.0, but the two more expensive boards include X-RAM and I/O modules.

The Sound Blaster X-Fi Elite Pro features professional-quality digital-to-analogue converters (DACs), as well as a large external I/O module (can be positioned vertically or horizontally) with a wide selection of connectivity for audio creation, and a fancy new remote control. The top-of-the-range board also features 64MB of on-board X-RAM - audio memory dedicated to higher gaming audio quality and performance - in addition to a built-in pre-amp for direct recording and high-impedance inputs for electric guitars.

The X-Fi processor is essentially a real-time hardware and software solution. Creative designed it as a flexible, programmable digital signal processor, which lets you reconfigure the sound card for different applications, like gaming, entertainment, and audio creation. It's made up of more than 51 million transistors and has a computational power of over 10,000 MIPS - equivalent to having a 3.4GHz processor in your PC. The chip has a clock speed of 400MHz and turns out a performance of 10340 MIPS (millions of instruction per second), which is actually marginally better than a 3.4GHz Pentium 4 chip (10200 MIPS).

In addition, the benefit of a low clock speed means less power requirements, so the processor could be ideal for mobile devices. Less power also means less heat, so there's no need for a noisy cooling fan. The processor also employs algorithms to sort out the multi-channel output from a simple stereo signal. What this actually means it that the chip analyses the audio to place the lead vocal centre stage and the backing in other channels. It also deals with three dimensional panning and can identify whether the sound should originate from rear or front speakers as well as from left or right.

It also features an SRC engine that is so precise that any audio resolution is converted to any other resolution at near transparency with 136db THD+N and digital-matched recordings in resolutions from 44.1kHz to 96kHz. The X-Fi even supports ASIO recording with latency as low as one millisecond with minimal CPU load.

X-RAM is reserved to allow game developers to store a game's audio directly to the audio card. This allows them to deliver very high-quality game audio or more detail (more simultaneous voices) without impacting on system performance. In some cases, depending on the implementation, you may even benefit from faster performance - although this is largely down to the game developers implementation.

The main method used today for games, most notably by id Software with Doom 3, is to compress the audio assets (typically using Ogg Vorbis compression), store them in system RAM in this compressed state and then decompress them as required. This frees up system RAM, but at a cost of having to run multiple Ogg Vorbis decompression streams in real-time. X-RAM can clearly help in this instance by providing a dedicated holding space for these audio assets in their uncompressed state and thereby save the CPU cycles that would otherwise be used to decompress them.

The X-Fi provides a new extension of the EAX Environmental Audio standard that was invented by Creative and is found in virtually all top PC game titles used today. With the new Xtreme Fidelity platform, Creative has delivered the fifth generation of EAX, which will immediately support hundreds of top games that are already available.

The I/O module's front panel offers a 0.25in. headphone jack, two 0.25in. line-in jacks, and line-in level controls. You can also alter 3DMIDI, EAX, CMSS-3D and Crystalizer levels. A blue LED lets you know when the overall volume is muted, and green LEDs indicate active processing functions. At the rear of the box are stereo RCA inputs that work as a standard auxiliary input or a phono input, full-size MIDI-in and -out jacks, as well as optical and coaxial digital connections.

Unlike the Audigy 4 Pro, the X-Fi Elite Pro doesn't have any FireWire or USB 2.0 ports, but the PCI card does have analogue output jacks for up to 7.1-channel multimedia speakers. And while the remote control is somewhat ugly, it is very useful - it can be used as the DVD remote control and the four scroll wheels allow you to adjust the CMSS-3D and Crystalizer settings from a distance. [9]