Important Issues and Conclusions

Let’s sum up here what the initial evaluation as well as our benchmarks are telling us about the new NVIDIA SLI technology. 


NVIDIA knows that performance and SLI are going hand in hand in the user’s eyes and they are making every stride they can to make sure that their new SLI technology offers the fastest game play anywhere.  On the up side, NVIDIA can claim big gains in the major titles we looked at here: HL2, Doom 3 and Far Cry.  What they can’t claim, and in truth haven’t done, is that SLI is going to increase your enjoyment of every game.  But though NVIDIA has never claimed that, many users may just assume that every game is going to be improved on by using SLI.  We can now say for sure that isn’t true.

Where this information might come into play directly is a user that is trying to decide between purchasing a single 6800GT card for their setup or going straight to dual 6600GT cards.  We have seen that performance on those two configurations is very similar on games that scale well with SLI.  However, after what we have seen here, I can guess with a great deal of certainty that gaming on EQ2 with a single 6800GT is going to far out shine gaming with two 6600GTs.  The same is probably true on Rome: Total War and Madden 2005. 

But where NVIDIA’s SLI is working, the performance gains are impressive.  60+% in HL2, 45+% in Far Cry 1.3 and 28% in Doom 3 are absolutely phenomenal.  I can assure you there are more than these three games that will see these improvements too.


There have been some initial concerns with the stability of SLI systems that others have mentioned.  I have to say that in my experiences, I came across nothing of the sort.  After working out my issues with the A8N-SLI Deluxe motherboard from Asus, my SLI test bed has been completely stable without a hiccup. 

Price and Value

Besides the advantages that SLI offers from a pure performance stand point, the other key benefit of SLI is that of the upgradeability it provides for a potential buyer.  NVIDIA SLI systems are completely capable of running in both single card configuration and dual card setups giving the SLI-ready motherboard owner a quick and easy upgrade path for graphics performance.

While the idea of buying $1000 in video cards today may seem more than a bit absurd, the fact that you can spend $500 on one today, and in 4 months (or whatever time span you need to come up with another $500), you can purchase another 6800 Ultra card to get the increased performance without throwing away your past investment.  And if all goes according to plan, in that four months the 6800 Ultra card would even go down to $400 or less, making the upgrade option even more intuitive. 

This idea is also extended into the mid range graphics market with NVIDIA’s 6600GT GPU that offers the user good performance for a $250 card and the ability to buy an additional one down the road for $200 or so to increase performance dramatically. 


There are still a couple of kinks to work out.  First, we need to see more user control options in the driver; we are getting this eventually with the additional options in the upcoming release of the 75 series driver.  We also need to see more games being implemented with support for SLI — this is a two pronged attack: from NVIDIA and from the developers. 

NVIDIA has already started working with developers to make sure they have the tools necessary to properly develop games that will scale well with multiple GPUs.  This doesn’t mean just NVIDIA chips, but also competing chips.  You can make a really good analogy to the current status of SLI by comparing it to HyperThreading and now multi-core processors.  HyperThreading and multi-core CPUs really have the same goal, to increase performance not by clock speed, but by parallel processing.

Unfortunately, most software doesn’t automatically take advantage of this idea; just look at how few applications are multi-threaded even after the success of Intel’s HyperThreading technology.  The PC software field needs time to change their development habits away from single threads and towards multi-threads, and now the same is being said of game developers.  In fact, they have double the task: making their physics and AI engines multi-threaded for upcoming processors and making their graphical engine multi-threaded for upcoming GPUs. 


There is no getting around the fact that NVIDIA has a big hit on their hands with SLI technology.  Our testing showed that SLI was able to improve performance on HL2, Doom 3 and Far Cry by as much as 65% at 1600×1200!  That is definitely going to put a cramp on the ATI camp.  There is simply no debate, NVIDIA has the fastest graphics solution on the market with SLI technology.

Be sure to check out my review of the first available SLI ready motherboard, the Asus A8N-SLI Deluxe.

Feel free to use our PriceGrabber service to find great deals on the 6600GT for SLI!

« PreviousNext »