NVIDIA's Scalable Link Interface: The New SLIby Derek Wilson on June 28, 2004 2:00 PM EST
- Posted in
Final WordsIn our conversation with NVIDIA, we noted that this technology should work with all software without any modification necessary, and NVIDIA was quoting numbers around 1.87x performance increase over a single card (under 3dmark '03). Of course, this may be an exception rather than the rule, and we do want to run our own tests (as impact will change over graphical complexity). Even more intriguing is the fact that NVIDIA talked about developers being able to take advantage of this technology in their games. It was indicated that, by doing so, games could see a linear (2x) performance increase. If realized, this would be unprecedented in real-world applications of this type of technology.
In speaking about why multiple graphics card configurations haven't seen more light in the recent past, NVIDIA mentioned that the PCI bus was the limiting factor in being able to execute something like this on modern hardware. At this point, they still have an unbalanced bandwidth situation due to the x8 bandwidth limit on secondary x16 PCIe slots, but that's nothing like the difference between PCI and AGP (especially as full PCI bus bandwidth can't always be guaranteed to one device).
And then there's the problem of finding motherboards with multiple PCIe slots. The only one that we've seen so far is a multiprocessor board, which hasn't been released yet. To be fair, NVIDIA is targeting the system builders first, and won't be pushing a consumer SLI upgrade package until later (possibly this fall). The success or failure of this product will likely not rest on its technical merits, but rather on the availability of suitable motherboards, and the cost of the upgrade. We can see some hardcore gamers out there spending $500 on a card. We could see some even going so far as to upgrade their entire PC if it meant better performance. But it is hard for us to see very many people justifying spending $1000 on two NV45 based cards even for 2x the performance of one very fast GPU; perhaps if NVIDIA cripples some of its GPUs to work only as slaves and sells them for a (very) reduced price as an upgrade option. Even then, this isn't going to have as easy a time in the marketplace as the original 3dfx SLI solutions.
Now, what would really work in NVIDIA's favor is if they engineer their NV5x GPUs with backwards compatible SLI technology. Even the promise of such a thing might be enough to get some people to pick up an NV45 with the knowledge that their future upgrade would actually be an upgrade. For those who upgrade every generation, there would be a way to get more power for "free", and those who wait 2 or more generations to upgrade might have a new reason to take the plunge. This scenario is probably wishful thinking, but we can dream, can't we?