X-Fi and the Elite Pro: SoundBlaster's Return to Greatness
by Derek Wilson on August 30, 2005 11:59 AM EST- Posted in
- Smartphones
- Mobile
New Features, Possibilities, and Modes
The main new audio processing features of the X-Fi line are the 24-bit Crystallizer and CMSS-3D. These features, as well as the onboard RAM and the three modes of operation (gaming, entertainment, and creation) will be explored in this section. We know what each of these features is and the basic principles on which they operate. While we could make a much more thorough analysis of the quality of these features, if we had some actual math to go on, it is understandable that Creative would want to protect their investment by keeping the intimate details of the architecture private. What we do know should be enough to go on for now.The 24-bit Crystallizer
The 24-bit Crystallizer takes 16-bit audio and tries to add dynamic range to the audio signal. If we were to convert our 16-bit audio stream to 24-bits, we could essentially do so by adding 8 zeros to the least significant end of each sample. It becomes clear that the highest value that a sample can take on is much less than the highest value possible with 24-bit audio. Likewise, on the low end, the audio stream isn't capable of representing values between zero and 256. The basis of the 24-bit Crystallizer is to fill in these least significant bits with meaningful data and thus, expand the dynamic range of the audio. What, exactly, is meaningful data in the least significant bits? We're glad that you asked.Audio engineers are big fans of compression. Applying compression to a sound decreases the dynamic range of a sound in order to preserve the loudest and quietest parts without clipping or burying the subtleties in noise. This is very necessary to make good use of 16-bit audio, as things like whispering over a snare hit are not easily representable otherwise. Knowing the basic manner in which audio engineers go about applying effects to sounds, Creative can try to reverse-engineer the process to add more data where it seems necessary.
Details on the technique are fuzzy at best, but we do have some information. The algorithm doesn't simply expand the audio signal; it looks for recognizable patterns in frequency and time and applies algorithms that fill in the data where necessary. For instance, the X-Fi hardware is able to detect something like a kick drum hit and use the sound and proportionally weighted, transient, low-frequency data to boost the impact of the event.
The algorithms focus on the energy flux in different frequency bands in order to localize the impact of the effect. This means that things like snare and symbol hits, the plucking of strings on an acoustic guitar, the slapping of a string on a bass, and gunshots in games should all become more distinct. Each sound will be enhanced according to its energy flux, frequency, and waveform. Creative states that this can even help clean up the high end on MP3 encoded files. What this doesn't enhance quite as well are quiet subtleties in the audio signal.
CMSS-3D
For 5.1 sources played on headphones with CMSS-3D, Creative uses HRTF (Head Related Transfer Functions) to virtualize the position of each audio channel around the listener. This technique is augmented with simulated environmental reflections, which attempt to improve the externalization of sound to the listener. These environmental effects are more subtle than the Dolby Headphone effects and are meant to convey a listening environment that matches the recording rather than one that fits the room in which the listener is sitting.When enabled for 3D virtualization with two speakers, the methods used are similar to that of the headphone implementation. Rather than adding environmental reflections, this CMSS-3D mode includes a cross-talk canceller to make sure that signals from one speaker are not destructively combined with signals from the other at the listening sweet spot. Unfortunately, there is still a sweet spot for listening to audio in this mode, but settings like speaker angle are easily adjustable.
Probably the best use for CMSS-3D has nothing to do with two speaker setups. Getting the most out of a 7.1 channel audio setup is much easier with CMSS-3D. We still don't recommend using CMSS-3D for stereo sources, but for listening to 5.1 audio, CMSS-3D will do a good job of fitting the 5.1 sound to 8 channels. For creating a multi-channel environment with a two-channel source (if we absolutely must), our favorite solution is still Sonic Focus' implementation on Intel hardware. It's a shame that they won't open up their software for other hardware.
64MB onboard RAM
The top two models in the X-Fi series feature 64MB of SDRAM on the sound card itself. This feature is called X-RAM, but that isn't a technical term. X-RAM is a marketing name given to maintain the X- moniker of the card itself. This RAM is supposedly included to enhance the performance of games. Until games are written to take advantage of this feature, we will have to simply accept the possibility for performance improvement.Creative has shown us some numbers that they have run using UT2K4 and a special patch that allows for playing over 100 voices at a time (currently only 30 are supported in the game), as well as uploading uncompressed sound files to the onboard memory. The numbers show a pretty big performance improvement when X-RAM is enabled in this case. Unfortunately, we don't know how real world this test is. Without having the patch to test ourselves, we can't really know what's going on. If we are more than tripling the number of concurrent voices, we would hope to see some sort of quality improvement as well. A performance improvement for a feature that isn't necessary is a useless test.
We really need to spend more time with games that currently support X-Fi to see if we can find a case where the extra RAM affects performance. Our best guess is that we won't see real impact from this feature until developers realize that they can target the Creative solution to deliver a higher quality audio experience. Playing audio with higher sample rates, adding voices, using uncompressed audio to save CPU overhead, and freeing system RAM for other uses should be quite attractive to audio designers.
3 Modes of Operation
The final major feature is the inclusion of three distinct modes of operation. This feature is necessary because of the complexity and flexibility of the Audio Ring architecture. Tradeoffs are necessary for every type of audio application, but a configuration that can switch between modes depending on the task at hand could be a major development in the "one size fits all" audio department. These are the features of the different modes.| Gaming | Entertainment | Creation | |
| Video Game Frame-Rate: | YES | NO | NO |
| Hardware 3D Audio Processing: | YES | NO | OPTIONAL |
| Environmental Effects: | YES | OPTIONAL | OPTIONAL |
| High-Resolution Audio Playback: | NO | YES | YES |
| Audio Enhancement Processing: | NO | YES | OPTIONAL |
| 2-Channel to Multi-Channel Up-Mix: | OPTIONAL | YES | NO |
| Multi-Channel Audio Recording: | NO | NO | YES |
| Hardware MIDI Playback: | NO | OPTIONAL | YES |
| Hardware Effects: | YES | YES | OPTIONAL |
| Sample-Synchronized Record and Playback: | NO | NO | YES |
| Low Audio-Streaming Latency: | NO | NO | YES |
| Bit-Accurate Audio Capable: | NO | OPTIONAL | YES |
Professional recording requires low latency, especially when using ASIO drivers. Therefore, it makes sense that Creative would implement a mode targeted at getting audio in and out of the Audio Ring as fast as possible. Effects possible in Creation mode are limited to those that can be performed very quickly, and audio comes through the chain as unmessed as possible. Less than 2ms latencies are possible in this mode. Again, our only complaint with the Elite Pro as a professional solution is its lack of balanced I/O.
Entertainment mode focuses on the music and movie experience. Options for enhancing both stereo and surround sources are pushed to the foreground and features like the 24-bit Crystallizer and CMSS-3D will likely be heavily used in this mode.
Gaming mode is optimized for creating a multitude of hardware accelerated voices and processing them to create the best real-time 3D that audio developers can throw at it. With up to 127 3D + EAX voices, extremely complex effects are possible. Under this mode, X-RAM can be used to assist in the storage and playback of audio files.
Facebook
Twitter
RSS
110 Comments
View All Comments
yacoub - Wednesday, August 31, 2005 - link
As does "it's just bloatware and marketing".Eskimooo - Wednesday, August 31, 2005 - link
PCIe is designed for graphics and high data transfer, but audio sends very small packets and the overhead can be big. Performance of PCIe is bad for audio, therefore no-one was tempted to come up with a product yet...Correct me if I am wrong.Creative says they are working on that, I have just came across this interview:
http://www.hardwarezone.com/articles/view.php?cid=...">http://www.hardwarezone.com/articles/view.php?cid=...
Araemo - Wednesday, August 31, 2005 - link
From that interview:"So what we have to do is go back to the drawing board and work on the transport part of the chip and re-design it to add more silicon to overcome some of the problems we had with PCIe. So for us to come up with a PCIe solution is going to take a while because we have to overcome the problems we're facing with that bus."
It sounds like they thought it would be a simple transition, and had their product mostly designed(around PCI 2.x) before they tried to adapt it to PCI-Express.
In order for sound cards to make efficient use of an overcrowded PCI bus(common in older chipsets, before the nforce era or so), they had to pull a LOT of tricks, including using a very low(relatively speaking) IRQ. W/ the PCI-express bus, they have to re-engineer their chips to send data earlier, since it is sent serially instead of parallel, meaning they can't buffer one big clump and expect it to get to the destination all at once, they have to send the first part when it's ready, and then the second part.. sequentially.. I just honestly thought that the delay in the X-Fi WAS to get pci-express working.. It's not like they haven't had plenty of time (What, 3? 4? years since the first working silicon was available for engineers to test on?)
I think if creative had a serious competitor, they may have been more eager to have pci-express support, but since noone else is even making a dent in their market, they only need to improve over their past product... and that isn't hard to do.
Spacecomber - Wednesday, August 31, 2005 - link
I was a little surprised to see that the X-Fi has a higher level of CPU usage and results in a sligthly lower FPS average when playing Battlefield 2 than what you can get with an Audigy card. I really would have hoped that all that onboard processing power would have taken a significant load off of the CPU, but perhaps this will improve with newer drivers down the road, as you seemed to suggest.I wondered if this might not deserve a bit of a closer look. An average of FPS, as you know, doesn't really do a very good job of capturing how well a game runs on particular system. This seems especially to be true with Battlefield 2. For example, when I run a timedemo of this game and then exam the cvs file, which captures the time for each frame rendered, I see that while my system gets an average of 50 fps, the range is from 2-106 fps. If you look at a graph of all these framerates, it looks prety ugly with all those momentary dips into single digits and low teens.
My wishful thinking is that a sound card that is capable of taking more of the load off of the CPU might help with this. Even if the average frame rate was slightly lower, if it cleaned up some of those framerate dips, it would still be a good thing.
By the way, how did you disable sound in Battlefield 2 for you tests? Did you simply lower all the sound settings to 0, or is there a command line switch or console command that will do this? I've been meaning to run a timedemo with no sound to compare to a timedemo with sound just to see if the audio contributes significantly to the framerate dips mentioned previously.
Thanks for this review. As an avid gamer, despite my frustration with Creative's cards, they still seem to be the undisputed gamer's card, simply because no one else fully supports all the 3D effects (such as the latest EAX features) in hardware that Creative does. And certainly, no other game card manufacturer is in the position (that Aureal was at one point) to challenge Creative with a competing set of 3D audio effects and features. Much as I'd like to jump to someone else's solution (I loved my Aureal card while it was supported, and I also was happy with my Santa Cruz when Turtle Beach kept their drivers up to date), I'm skeptical that any one really has the clout, now, to establish themselves as a solid card for game players or that they could survive under Creative's shadow.
Spacecomber
jr9k - Wednesday, August 31, 2005 - link
[quote]We therefore see slightly lower performance from the X-Fi card. With the X-Fi being brand new, driver improvements could also change the performance picture over time. [\quote]Given creative's past record, don't count on them.
Seems a nice card though, once it is available at 50$
ceefka - Wednesday, August 31, 2005 - link
So if you do run a comprehensive audio test, please also differentiate between Intel and AMD machines and subsequently Intel, nF3 and nF4 chipsets. Also vary on graphics cards. It is said that a higher grade PCI-E graphicscard on nF4 increases latency. Maybe you can shed your own light on that. Please use excessive amounts of audio and processing and push the systems real hard.While the X-Fi looks to have some nice tech to it, I am afraid that a lot of its tech will sit unused for years to come while missing a few attractive things like Dolby Digital Live and balanced inputs.
Eskimooo - Wednesday, August 31, 2005 - link
I have read DDL may introduce delays like the DICE did with first XBOX. This whole DDL does not mean cinema quality and does not make a card. DDL is not as goog as full dolby. And it always means compression. So it is just a feature which I can live without. I have good analog set anyway. Balanced inputs are important for those who need them. I presume EMU will come up with something but I do not think I want to wait. X-Fi is the best option for me, thanks for all your comments that helped me a lot. Does anybody know where I can order it in Europe?stmok - Wednesday, August 31, 2005 - link
I've been using dual CPU (and now dual-core) systems for quite a while, and Creative have dissappointed me time and again with their Windows drivers...Constant "pops and clicks" is always present with the Live and Audigy series. However, this doesn't occur in Linux...For some reason its fine. (I guess its a different driver team working on it).So my question is, does this new Creative solution suffer from the same issues as its older ones? (Where you are forced to either try third-party drivers OR disable Hardware Acceleration just to get rid of the "pops and clicks" in games/videos/music)
The Blue Moose - Tuesday, August 30, 2005 - link
Let's assume you actually need a semi-pro sound card. Is Creative really going to be your first choice? At the $400-$500 price point you have a few options. Given Creative's less than stellar track record with drivers and software support, only those who insist on the absolute cleanest sound above all else will jump right into this one. This will be those who can (or at least think they can) hear the difference between Audigy sound and X-Fi sound.So, now let's look at the more mainstream version. $130 for a card that uses lesser components (therefore will show even less difference from current Audigy cards), won't have the on board RAM, and doesn't do Dolby encoding. I can get the same sound quality, WITH Dolby encoding for $100 or less right now. Plus the same driver/support issues apply here as well.
Now, most hardcore gamers aren't gonna pop for a semi-pro card they don't need, nor will they skimp by grabbing the low-end board. I'm assuming the $280 version will have middle of the road components, but it will definitely have the RAM. They won't buy it for cleaner sound necessarily, but more for the potential performance boost of the RAM.
But, how much of a boost will there be? The (admittedly limited) benchmarks would seem to show there's a good bit of driver overhead. Also, with dual core chips filtering down to the masses, will the RAM actually get you that much more? Many game designers have said how very hard it will be to make games that can effectively use a dual core rig. So, if they can't send graphics related work to the 2nd core, what are they gonna do with it? The most likely candidates are sound, physics, and AI. If you've already got a decent sound card, I think you'd get more milage out of your $280 by dropping it on a 2nd core than a new "faster" sound card.
While the tech behind this card, certainly seems impressive. The card just seems to be a lot more about hype and clever marketing than any real leap in sound cards. The article mentions plenty of analog and digital I/O, but the picture used doesn't even show a digital output (but it does have a outdated game port, strange). There appears to be a connector for a daughter card, but I don't recall a mention of it. I'm not saying the thing is a piece of crap, but at the prices they're asking, you're paying more for the SB name than the card itself.
DerekWilson - Wednesday, August 31, 2005 - link
oh, and there is a clear audible difference between X-Fi and Audigy cards.The coloration from the poor frequency response and IMD sweep at 16-bit 44.1kHz really deadens cd auido and mp3s. Its not about a slightly higher noise floor or a little less dynamic range. It's about poor sound reproduction and bad sample rate conversion.
I agree with you on the point of your post though -- it is hard to justify the price of this card.