X-Fi Processing Elements: The Quartet DSP

Audio effects and processing can be done on a CPU. The latest audio solutions from Intel employ software from Sonic Focus that performs audio processing without the aid of dedicated hardware. If an end user wishes to enable advanced filtering or processing features, the Creative X-Fi has the advantage of being able to perform these tasks without tasking the CPU (thereby freeing up resources for other applications).

As is often the case, a general purpose CPU is not the most efficient hardware for the job. The Quartet DSP is able to make quick and efficient work of audio data. As mentioned before, the Quartet is made up of 4 independent two-issue SIMD engines, which Creative calls a TIMD architecture for Thread Interleaved and Multiple Data. The configuration of the SIMD paths in Quartet lend themselves well to audio processing.

Creative didn't tell us how wide the data path is down each SIMD pipe, but Quartet is able to handle either integer or floating point data, making it more flexible than DSPs used on older Creative parts. Special instructions allow differing operations to be performed on SIMD data to enable more efficient audio processing. For instance, the FADDSUB2 instruction performs an add-on-one data path and a subtract on another. The DSP is also able to perform complex floating point math with the real and complex results completing in different paths.

In traditional DSP architectures, raw speed often wins out over programmability. Tradeoffs are always necessary, but the Quartet offers a good balance. The result of one instruction can be used in the next with no stalls or reordering necessary and any instruction can be performed after any other instruction without any conflict. Also, any register can be used as any operand in any instruction. While we don't have all the details on the hardware, a high level language compiler could easily target and optimize for this architecture.

At this point, an easy to develop and efficient compiler only really helps Creative write driver and feature code more easily. It could be possible for Creative to allow developers access to their compiler in order to develop specialized DSP code. We don't know if Creative will actually pursue this in the future, but the option is there should they choose to do so.

To sum up the capabilities of the Quartet DSP, we have this list of features:
  • 2 SIMD units per each of 4 simultaneous threads
  • fixed and floating point data supported
  • 235 opcodes
  • up to 1200 MIPS
  • can perform up to 4 moves per instruction
  • easy to compile and optimize
Bringing the entire Audio Ring architecture together, Creative has quite a powerful solution that can handle lots of quick and efficient processing. Multiple audio streams with multiple sample rates can be floating around, being processed and reprocessed with high efficiency and low latency. This gives Creative a good deal of freedom in how heavily they can process audio without needing any assistance from the CPU.

X-Fi Processing Elements: Exploring the SRC New Features, Possibilities, and Modes
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  • NovaPolice - Wednesday, August 31, 2005 - link

    Yeah, I'm somewhat curious as to how the crystalizer does in comparison to Qsound's methods, Qsizzle, Qrumble, and Qexpander, which I have enjoyed for a while. Probably the best candidate for comparison would be the envy24(with-some-tricks)-based PSC724 Ultimate Edge. Of course.... that thing only costs 30 bucks at outpost, and philips is kinda bad at releasing drivers.

    I wish Qsound Labs would create some kind of hardware chip. Some kind of alternative to the various successions to EAX. Their expander kicks ass.

    Or it would be nice to see something with Creative's hardware power combined with Qsound's algorithms.
  • flexy - Tuesday, August 30, 2005 - link

    >>>
    i highly doubt it. Better save your money and invest in better speakers [if not already]..this is really all bunk. ALL they can sell is features and irrelevant addons/gadgets/specs...specs which are only relevant MAYBE for hardcore pro-musicians. But then i dont know any pro-musician who does his recordings on a creative card :)
    >>>

    Btw, i also highly, highly doubt that for listeining to music/mp3s etc. people will notice a difference (towards the better) with a VERY old AWE32/64 card compared to any of the newest cards out right now. I remember actually that years agomy AWE64 had this certain "punch" to her which i liked...and i cant even necessarely say that for listening to music my current Audigy2 is noticeable "better"...but then this is a long time ago :)

    Anyway...leave 'em the fun to sell their products with dumb marketing terms....and as stated elsewhere...hope that the OEM/lower end cards will be much cheaper. (For what it's worth)
  • Calin - Wednesday, August 31, 2005 - link

    I found also that my Creative Sound Blaster 16 (ISA card, with 2x4W amplifier on card) sounded more "musical" (let's say I consider it better sounding) than the newer Audigy 2 gamer

    Calin
  • Wellsoul2 - Tuesday, August 30, 2005 - link

    I went from SBLIVE to Chaintech VIAEnvy to Audigy 2 ZS.
    It would be nice to have a card good in games and music.
    Subjectively I think the Audigy 2 ZS better with MP3's and games than
    the Envy Card.

    Also I've found that the software makes a big difference.
    Anyone notice that Itunes free player sounds much better than Windows Media Player or
    Creative Player? (With any audio Card)

    I really liked the ViaEnvy sound but it really won't do games well.


  • flexy - Tuesday, August 30, 2005 - link

    i never use the creative software, neither do i use itunes.

    If i want to have highest quality sound then i use foobar2000 with kernel streaming or foobar/winamp with direct asio (plugin) output. I dont think there's anything better right now (in terms of player/output/quality)
  • Parak - Tuesday, August 30, 2005 - link

    Seconded, would love to see a matchup of this card versus Envy24 solutions.
  • imaheadcase - Tuesday, August 30, 2005 - link

    "Creative informed us that cards should be shipping as of last week, but we still can't find them online or in stores. Even Creative's own site lists the X-Fi line up as pre-order. We will have to check into the availability of these parts as we certainly don't want the recently ATI disease (“paperlaunchitis”) to spread to the rest of the computer industry. "

    Actully you can order it on creative site, I see you can do it as i type this. Also can purchase it at Best Buy, they have dozens of them on display. There are 3 online retailors that have it listed. Was this artical typed out a week ago or something? lol

    I will sum of this card for everyone: Wait a few months, and you can get it for a little over $50 for cheaper one. The high end card are pretty much same as cheaper one, you just get some extra CRAP with it. Pretty much %90 of the stuff on card is useless to the average user. This is essentially a Audigy 5 card...go go marketing from creative :P
  • HardwareD00d - Wednesday, August 31, 2005 - link

    I saw an X-Fi card in Best Buy last week (Phoenix AZ, US) Looked pretty neat and I had just heard of them, so I was surprised to see it on the shelf so soon.
  • missleman - Tuesday, August 30, 2005 - link

    All that mumbo jumbo doesn't look like it will have any real use for me.
  • HardwareD00d - Wednesday, August 31, 2005 - link

    Tom's Hardware seemed to really like this card. They were much more impressed by the sound than Anand was.

    http://www.tomshardware.com/consumer/20050818/inde...">http://www.tomshardware.com/consumer/20050818/inde...

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