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Chrome goes Multi
S3 has wisely decided not to try and limit its multi-GPU solution to certain chipsets, despite the fact that S3 is owned by VIA. MultiChrome should therefore work on any motherboard with two PCI Express x16 slots, regardless of the core logic chipset onboard. Also, because it involves only low-end graphics cards, all MultiChrome configurations are "connectorless"—they don't require the use of an external dongle or bridge connection of any kind. Data are passed between the cards solely by means of a PCI Express connection, as has been the arrangement on some low-end multi-GPU configs from ATI and NVIDIA.

MultiChrome is right at home on the Asus A8R32-MVP Deluxe mobo

Like those other multi-graphics solutions, MultiChrome relies on a database of game profiles in order to determine when to do its thing and which load-balancing method to employ. S3 currently has profiles for about 50 games, including many of the more popular titles of the past few years. S3's drivers don't expose any back-door means for users to tweak or create game profiles themselves, so the existence of a profile will be crucial to MultiChrome's effectiveness. If the game doesn't have a profile, it will simply run on one card, without the performance benefits of dual GPUs.

Right now, S3 has only implemented one of the two most common load-balancing techniques used in dual-graphics solutions: alternate frame rendering (AFR). AFR is used widely because it offers the best performance scaling by boosting both vertex and pixel throughput. S3 says the other technique, split-frame rendering (SFR), is coming soon but isn't yet enabled in its current drivers. Without SFR, MultiChrome won't work with certain games whose rendering engines don't play well with AFR. I suspect that's why MultiChrome showed no performance benefit for us in Half Life 2.

We were also foiled in our attempts to test MultiChrome performance in Elder Scrolls IV: Oblivion by the lack of a profile for the game. In fact, we found that the game would crash from the graphics options menu with even a single Chrome S27 card. So long as I didn't change any graphics options, the game ran fine, but the crash was a disappointment. Oblivion itself isn't exactly known for being a rock of stability, so I hestiate to lay all blame at the feet of S3. Still, without a means of tweaking profiles, owners of MultiChrome rigs will be forced to rely on the volume and frequency of S3's profile updates in order to take advantage of that second card.

MultiChrome in action
MultiChrome itself is very simple to use. Simply check a box in the appropriate tab in S3's control panel, and it's working. It takes a second or two to initialize, but no reboot is required.

Yep. Do 'er. Thanks.

Once MultiChrome is enabled, you'll see a balloon help message each time the computer boots, indicating its status. This is more than vaguely reminiscent of how NVIDIA has chosen to notify the user about the presence of SLI, but that doesn't make it a bad thing. Users may turn off this indicator via the control panel if they wish.

deja NV

Also much like SLI, MultiChrome can overlay a load balancing indicator on the screen in any 3D application. The indiciator is more intuitive and easier to read than NVIDIA's, but it doesn't offer any information about which load-balancing method is in use—not that it matters just yet.

That's the load indicator in the top-right corner

I may someday be cosmically punished for saying this, but MultiChrome has, well, polish. S3 is quite evidently aware of its underdog status in the graphics market, and the company has obviously taken care to refine its drivers before allowing early adopters and us press types to get our hands on them. The lack of support for split-frame rendering is not a trivial omission, but MultiChrome is still more hassle-free and stable than either SLI or CrossFire were upon their initial public releases.

About that third eye in the middle of your forehead..
Now that I've said something nice, I'll also point out something less pleasant. The true gamer who buys and owns an S3 Chrome S27 card will probably face notices like the following quite regularly, which we encountered during just a few days on hands-on testing with the cards.

To S3's credit, both of these games loaded up and ran just fine on the Chrome S27, with excellent image quality and smooth frame rates. Still, if it wants to appeal to gamers, S3 needs to hire a guy (or a few guys) to help make these kinds of notices go away. I was also disappointed to see that the high dynamic range lighting in Half-Life 2: Lost Coast wasn't functional on the S3 card. I understand Valve uses an integer texture format for its HDR algorithm that would probably work on the Chrome S27, if S3 worked with Valve to make it happen.