Limitations using the ExpressCard Interface
Beyond the operating system issues, we should mention the limitations of the ExpressCard interface itself.
First, let’s consider traditional graphics bus interfaces. The older AGP 8x bus provides one-way bandwidth of 21 Gbits/s, and even by today’s standards this is a good amount of bandwidth for a graphics card. The newer PCI Express 16x standard for video cards can push 40 Gbits/s in both directions simultaneously, which is probably more than current graphics card technology really needs for a single video card.
Now let’s look at the ExpressCard bus. It’s based on a PCI Express 1x connection, with about 2.5 Gbits/s of bi-directional bandwidth available, which is a small fraction of what even the older 8x AGP standard can push! When it comes to graphics card technology, the ExpressCard bus is functionally very close to the ancient AGP 1.0 standard, about a quarter the one-way bandwidth of AGP 4x and an eighth of AGP 8x. Yikes!
This bandwidth limitation is most certainly going to limit the performance of an external graphics solution using the ExpressCard interface. The question is: how much will it limit performance, and how much better than the integrated graphics solution will it be? Well find the answers to these questions when we benchmark the hardware later in the article. Now, though, let’s talk about installation.
Installation and Usability
As we mentioned above, the ViDock is picky about the operating system it’s run on. The laptop we had originally chosen for testing was a Gateway model with Windows XP and a Geforce Go 6100 integrated chipset. As Windows XP supports multiple video drivers at the same time, we planned to be able to use the ViDock Pro Radeon version, as the Geforce version was not available for us to test.
As we mentioned above, though, some manufacturers do not strictly support PCMCIA configuration/booting procedures in the BIOS. The Gateway laptop we had slated for testing simply would not work without a new BIOS that would address the problem. Since we couldn’t find any appropriate BIOS available, we were out of luck.
In the interests of completing our review, Village Tronic supplied us with a Dell laptop for testing that used Windows Vista and had an integrated Radeon Xpress 1150 video chipset. Because we were using Vista, the version of the ViDock had to match the internal chipset of the laptop, so we were good to go with the Vidock Pro Radeon edition.
On this second laptop, installation was relatively quick and painless. We simply installed the driver, plugged the ViDock in, rebooted, and everything was good to go. When there’s not much to report as far as an installation goes, that’s a good sign.
Once we were up and running, things went relatively smoothly. To the developers’ credit, we encountered no show-stoppers on the pre-release software and hardware, although we did run into a couple of glitches.
The first annoyance we found was linked to the ViDock’s bundled VT Multidisplay application. The application is quite robust, and offers powerful control of multiple display configurations, window management, display profiles, cloning, and a host of other features. However, we found the early release a little unreliable, in that there were times that it didn’t seem to implement our screen configuration choices. We ended up setting the display configuration within the Catalyst Control Center, which offered us flawless control of all of the multiple displays, even those of the ViDock.
The second annoyance was an intermittent display flickering we had experienced on rare occasions. We couldn’t find an obvious cause for the problem, but it was a little distracting, although when we launched a 3D application it seemed to disappear.
Aside from these two annoyances that we hope will be addressed before the ViDock is released, the unit worked like a champ. 3D applications were greatly accelerated compared to the integrated graphic chipset, as the benchmarks below will demonstrate, and the power of the ViDock to drive the multitude of displays was impressive to say the least.
Now that we know the ViDock can handle multiple displays with relative ease, let’s see what kind of 3D graphics prowess it brings to the table.
- Upgrading your Laptop
- ViDock Gfx PRO: Features and Specifications
- ViDock Gfx PRO: First impressions and examination
- Operating System Factors and Workarounds
- Limitations, Installation, Usability
- Test System and Configuration
- Game Benchmarks
- 3D Application and HD Video Playback Benchmarks
- Modifying the ViDock for use with other graphics cards: the Radeon 2600 XT and 3870