Is there a way?

I have an Express card slot in my laptop which is Inspiron 6400, can i put an external graphic card in it using this:-
http://www.magma.com/products/pciexpress/expressbox1/index.html
If so can anyone explain if it works? And how it works?

 

Yes I think there is a way. Asus has something similar too. It works pretty simple. Plug in the external graphics card into the express card slot. Connect an external LCD to the external graphics card. Install drivers and so on. Use the laptop with the external graphics and external monitor. You can not use your laptops display.

 

The only problem is, that while it would work, the bandwidth is still pretty low. I think it would be an upgrade for the X1400 in the E1505, but until a review has been posted from a decent source I cannot say for sure. Rumors have the bandwidth choking anything more powerful than a X1600 or 7600.

 

It's too bad this and the Asus require external monitors. (well, that, and the bandwidth bottleneck).

It would be pretty nice to be able to plug in a desktop graphics card and run it through the laptop display...but I guess there just isn't a market for it. Considering no one has made one for that specific purpose, far as I know.

Perhaps one day an 8800 GTX can drive a laptop monitor...

 

You aren't the only one hoping for that.

From what I was saying earlier, about the performance being similar to the X1600...that is about twice as powerful as what the E1505 has, so you might benefit...especially if you have an external monitor. You'd really benefit if you have integrated graphics.

There is a PCI-e 2.0 specification coming out soon, that might allow for true external graphics cards that can use laptop LCDs. We're all holding our breath to see how this pans out.

 

The problem with using a laptop LCD is how. The bandwidth would be used entirely for the graphics card and its communication between the laptop and the external GPU(and even then, only a percentage of the GPUs total power due to its bottleneck). What other way to send the signal from, the USB ports? Most notebooks have video out but almost none have video in, so that raises an even better question, without the fact of an external GPU. How would a notebook have video in?

 

PCIe2 is supposed to allow links up to (I think) 5 or 6 feet away. The standard graphics card link is x16, so let's say x8 down and x8 up (back to the LCD). You might even be able to do x12 down and x4 up, but I'm not sure. It would just utilize either a new type of ExpressCard slot or a new slot entirely. A dedicated power supply for the graphics card would probably be needed, but the laptop could also have integrated built on the motherboard to use when the external card is not going to be used.

Most graphics cards (and probably all graphics cards) wouldn't even stress out a x8 link AFAIK, so this approach might work.

 

That would require even more bandwidth, feeding back through the ExpressCard. It's not gonna happen. There's a market (hell, I'd buy one right now if it existed), there just isn't the capability to make it. You wouldn't get decent acceleration doing it, because those graphics cards push too much data, and the interface is too "narrow". You'd be surprised at how fast data moves internally in your computer as compared to externally. An ExpressCard slot will move at maximum 2.5Gb/s. A PCIe 16x card inside your computer has a theoretical maximum of 40Gb/s. Even a 4X AGP card transfers at 8.5Gb/s. You just won't get the performance you need in order to run a fast card on a laptop's display like that, not to mention the latency issues you'll get by having to re-route the graphics signal.

Some quick calculations: Let's say, 32 bits per pixel, on a 1280x800 display (conservative any more). That's 32,768,000 bits per frame. You want to play at 30fps, so that means you'll need 983,040,000 bits per second, or 1Gb/s, just for the display data, heading back. There's overhead of all kinds of other things, and that's only at 30fps. 60 frames per second would saturate a PCIe bus completely, just for the display. And that's at a lower resolution than many gaming-grade laptops would support. You want to run at 1400x900, which is available in a 14" machine any more? That's 1.23Gb/s on the way back for 30fps. And the processor and front side bus would have to route that much information to the display controller on the laptop, which would mean that they wouldn't have any bandwidth left to do most of the other processing required for gameplay (it's not all in the graphics card.).

In short, it's just not going to happen. The external card driving it's own monitor with it's onboard DDC is enough of an engineering feat, getting the data routed correctly and fast enough for the feedback speed required for gaming. It just ain't gonna happen having it feed it back into the laptop, unless they make the laptop specifically cater to that design, such as a direct pass-through video input of the laptop. Which would be pretty sweet. Just unworkable with current designs.

 

I'm talking about PCIe2, but yes I agree it is a stretch on future technology. Modular GPUs have pretty much been a bust.

 

Still, nothing would ever be available on current equipment.

And PCIe is full-duplex, so the 2.5Gb/s is in both directions per lane. You would get 16X speeds in both directions at the same time, you don't have to split it like you were doing in your calculations. Graphics cards currently don't stress the bandwidth because the data being pushed is just textures and vertices, then the heavy lifting and memory usage is done on the card, and then displayed directly by the card. If you tried pushing rendered graphics back over the PCIe link, you'd run into problems (which is basically what's being proposed here).