SLI Technology

Innovation in a Nutshell

At the end of the day, all you really have is hardware and software working cooperatively to produce a better and faster way to render 3D images on the fly. The developments of video card technology were full of interesting innovations. Initially, 3dfx was at the head of the pack, but their fault lay with trying to milk their old technology for everything that it was worth even when it was past the expiration date. At the same time, nVidia cruised down the road of innovation. And then ATi sped by in a Ferrari. nVidia played catch up to ATi, and the two companies became arch rivals for years. Within the last year, nVidia’s SLI technology has pulled nVidia ahead onto the bleeding edge of innovation, while for the moment, ATi has been left back. It’s going to be quite interesting to see what happens when ATi releases their finalized CrossFire technology. There is on-the-fly rendering mode selection and alternative rendering methods.

While CrossFire has been scheduled for release with all of these features, SLI has not been. As ATi announces what will be in their driver package, nVidia counters and tries to duplicate it with yet another patch or update to their existing driver set. For instance, after ATi’s announcement of successfully implementing SuperAA, nVidia countered with the release of their version of SuperAA. After ATi’s announcement that cards built by different manufacturers could be used in a dual-card setup, nVidia released this feature in version 80 of their ForceWare drivers.

Basically, it’s a cat and mouse game that the two companies are playing. Many die-hard ATi fanboys expect that when ATi is ready, they will release a nearly flawless product while nVidia is still releasing patch after patch to address bugs and to counter whatever features ATi comes up with. This goes to show which company is really driving the industry. The only advantage at this time to consumers is that nVidia’s product has been made available, while ATi’s product still has yet to hit store shelves in some form worthy of implementation.

Which Route Should You Take?

If you do not have any SLI-capable parts, you’re not locked in to anything. You can freely invest in either nVidia or ATi. The only thing is that they cannot mix and match technologies. For example, if an SLI motherboard is used in a computer, ATi cards cannot be used in dual GPU mode, and visa versa for a CrossFire motherboard. This is a totally new platform of video card technology; a new page, if you will. Builders have the opportunity to start fresh. However, if someone has already invested in nVidia’s SLI technology for their computer system, they’re pretty much locked in unless they seriously want to get rid of it or build another system.

Either way, be sure to keep an eye out for hardware reviews on SLI and CrossFire technology to see who pulls ahead.

The Last Word

For the sake of staying consistent with the topic, if a builder were to choose to go with SLI technology, there a few things to take into account when looking at the price of the hardware, the resulting performance benefits, and the kinds of high-end games out on the market.

First off, it may be slightly cheaper to get two weaker cards paired off with SLI, but ultimately, the overall performance usually turns out to be far better with a single all-powerful card. It’s the same with any piece of hardware. RAM, for example, usually runs a bit better with one large stick, rather than two or more smaller sticks (this applies double for overclocking).

Remember, if there are powerful cards running in SLI configurations, very few games actually fully utilize that graphics power to a noticeable degree (archived page here). “Noticeable degree” is specified here because the human eye will not be able to detect the difference between 75FPS and 100FPS. The human eye can only detect roughly 24FPS on film, and about 30FPS in games, and sometimes up to 60FPS with the critical eye because of the lack of movement blurs like in film to fill the “gaps” in between frames. Anything significantly higher than 60FPS is overkill, thus is not worth paying the extra $300-$400 for a second video card that will bump up the FPS to 100. This is an ineffective use of money in order to gain an imperceptible gain in performance. As games get more and more complex, they will eventually require more powerful hardware to render them, but as it stands, the hardware has currently exceeded software performance demands.

Additionally, some of the more resource-dependant games are CPU-bound, rather than graphics card dependant, because of the hefty physics calculations required, such as in Doom 3, Half-Life 2, and most notably in Half-Life 2: Deathmatch. Using SLI technology for future upgrades, rather than obtaining dual video cards immediately is a bit more practical. After all, it was originally 3dfx’s intention.

If a builder does go with an all-powerful card, later down the road when it’s time for an upgrade, the same card could probably be obtained for about half the price. So, by installing the second card in the SLI setup, it will nearly double the rendering performance, thus extending the life of a gaming machine at a relatively inexpensive price (compared to the price of a new system).

Furthermore, nVidia SLI drivers are still in their infancy and need some more time to mature. Even when SLI is enabled, there is no guarantee that you will see performance increases in games because there may have not been enough tweaking to optimize the ForceWare drivers for all games. Plus, there are various bugs with various games with various settings within the driver set that still need to be addressed. By the time the drivers do mature, SLI technology will most likely be extensively supported by a much wider range of games, and will be able to utilize it to a greater degree. The hardware groundwork for SLI is pretty much all laid out, so chances are, it isn’t going to go through significant changes within the next year or two, or even three.

For these reasons, if someone does choose to invest in nVidia’s SLI technology, investing in a single all-powerful card now and one later appears to be the best road to take, not counting, of course, the “coolness” factor of running a dual-card gaming rig.

(Originally published on pcmech.com)