Why is a Cardbus to PCI adapter so expensive?

March 22, 2004 9:07 PM

This product is really cool, but why is this thing so damned expensive? It seems like a simple enough idea: a Cardbus to pci adapter allowing the mobile user to add more powerful equipment. PCI video cards beat the hell out of crappy 2x AGP 8mg mobile cards. PCI Audio cards blow the pants off built-in sound. This should cost $50 bucks, not nearly $1k. Am I missing something?

The other way around is dirt cheap. Ain't fair.

posted by Grod to Computers & Internet (10 answers total)

I, too have lamented the fact that cheap PCI bridge solutions just aren't available. There's certainly no technical reason why they're expensive. The electronics are ridiculously simple (it's just a PCI bridge chip). I think it's because the markets these guys sell to have buyers that are willing to pay high prices: professional audio, medical, aerospace, etc. They're also low-volume, but one would think they'd move more product if their prices weren't crazy.
posted by zsazsa at 9:22 PM on March 22, 2004

Response by poster: You say "it's just a pci bridge chip" does that mean it is possible to build such an adapter out of readily available components, or are there real obstacles? I imagine finding someone to code a driver would be a problem, but is there any problem with assembling the basic components?
posted by Grod at 9:27 PM on March 22, 2004

Back when Intel was really pushing AGP they developed a non-integrated 3d processor. I forget the name but I do remember that the video cards came in PCI and AGP flavors. The PCI version used a AGP->PCI bridge chip in addition to the GPU. The Intel cards sold for entry level prices so I imagine that making a PCI->PCMIA device wouldn't be much more difficult than your average RAID controller or cheapo sound card or similar device.
posted by yangwar at 10:11 PM on March 22, 2004

It won't help you in the video department but have you considered going USB for your other needs? The Soundblaster Extigy is supposedly a decent external soundcard.
posted by yangwar at 10:12 PM on March 22, 2004

Response by poster: Interesting, except that if I wanted to make a RAID controller I could look it up or even just ask someone how. I don't know anyone who could explain the proccess of making a PCI->PCMCIA . If you can explain it I'm willing to try it. Thanks.
posted by Grod at 10:17 PM on March 22, 2004

I think you just answered it in part. The market for these things is small on the demand and supply side. That makes for higher prices. It doesn't help that the folks who really need these are generally creative professionals for whom $1000 is a small equipment investment. Especially if you consider how cheap desktop PCs have become... there just isn't a hell of a lot of reason to buy one of these.
posted by scarabic at 2:00 AM on March 23, 2004

This is expensive fora couple of reasons: because casing, power supplies, backplanes, and CardBus housings cost more than just "a card" to manufacture, and because so few people need it. Back in the olden days, I had an ISA expansion chassis that was even simpler than this: a pair of ISA cards, a big honkin cable, and a backplane. Apart from the cable, which was pretty fancy stuff, the whole thing could have been made from parts for $200 at the time. IBM sold them for over a thousand, if I remember correctly, and remember, these are 1980s dollars.

PCI -> PCMCIA is harder than this and not terribly useful for VGA or audio; the PCMCIA/PC-Card bus doesn't have much bandwidth, and doesn't do DMA. CardBus is much better for such an application, being pretty close to a PCI bus in a lot of respects, but I still have my doubts that you'd want to run VGA of any kind across the northbridge, CardBus controller, a PCI bridge, and over the puny little cable. This can't be faster than even the scrawniest on-board VGA.

Not counting driver work, which would be considerable, I'd consider such a project daunting.

yangwar: You're thinking of the Intel i740, which eventually became the on board video for the i810 and i815 chipsets, but was first sold as a card. It was sold as entry-level mainly because performance wasn't on par with other current mid-level 3D hardware such as Rendition's and nVidia's. It was close to the bottom end of the market.
posted by majick at 5:45 AM on March 23, 2004

Response by poster: Interesting. majick I know that margi makes a product called display-to-go which appears to act as a secondary video card but without a complex gpu, it just offloads the work of handling multiple monitors from the inbuilt video card. I have also seen various pcmcia implimentations of video capture. Nogatech used to make a pcmcia tuner card, and Margi also makes a product called DVD-to-go which is a pcmcia card that offloads mpeg decoding and processing from the cpu (since most laptop dvd players use a software based decoder). With all of this, why is there no way to run circles around the shitty ATI 8mb card in my laptop?

All I want to do is improve its video performance, allowing me to play a couple games and enjoy hardware based viewport rendering in 3ds Max. Is that so much to ask?
posted by Grod at 12:18 PM on March 23, 2004

"Is that so much to ask?"

It is. Geometry and texture data utterly soaks bus bandwidth. Intel put out the AGP spec because PCI (which CardBus is very similar to) couldn't handle enough data to do interesting 3D things, like games. They threw in a bunch of dubious features as well, like mapping texture data into main memory, but the bus bandwidth is the main thing.

Putting video capture or MPEG decoding -- which is pretty low bandwidth stuff -- on a card is a great idea, and if your applications can make use of it, go for it. MPEG decoding is all number crunching, and video is just a trickle of data compared to, say, a 3D shooter.

2D VGA displays are, as I said, something CardBus (but not PCMCIA, which is different) could handle, and this Display-To-Go looks like a slightly shittier version of your on board video (possible the same ATI Mach64/Mobility chipset) tacked on to the CardBus. If that's useful to you, there's no doubt it'll do the job; they aren't claiming the impossible.

In theory, you could offload triangles to a CardBus card for 3DS viewport rendering, but practically speaking the demand for middle-low-end 3D hardware to do so is pretty nonexistant, and there's no way you could expect to move zillion-polygon models across the bus.
posted by majick at 7:47 PM on March 23, 2004

Response by poster: Thanks for the explanation. Sorry if I was being a bit thickwitted. I guess I'll just have to make do until I can upgrade to a new machine. Not that big a deal but, cheap bastard that I am, I was hoping to just tack things on to my existing system.

Thanks to everyone who took the time to post.
posted by Grod at 10:16 PM on March 23, 2004