Learn more about NVIDIA SLI

NVIDIA SLI Solutions

SLI GPUs
NVIDIA SLI GPUs deliver powerful, elegant and super-rich graphics for games and other graphics-intensive applications. Combining two NVIDIA SLI-certified graphics cards in a single system allows you to essentially double your graphics performance (up to 2x). NVIDIA SLI-certified GPUs feature dedicated, built-in SLI hardware and take advantage of the additional bandwidth of the PCI Express bus architecture. Connected by the SLI connector**, each GPU has a maximized connection pathway, and can leverage the second card for reaching top-speed performances on a single display. Professional users can also take advantage of SLI technology on dual NVIDIA Quadro GPUs to span an OpenGL window across multiple displays. Unlike previous dual-card solutions, NVIDIA SLI can output in both digital and analog formats for the highest image quality.

How it Works
An NVIDIA SLI system includes a PCI Express motherboard that supports two physical connectors that are capable of having two NVIDIA-based PCI Express graphics cards plugged into them. Joined by the NVIDIA SLI connector, the two graphics cards power one monitor, delivering earth-shattering PC performance. Screenshot courtesy of 3DMARK03.

** The NVIDIA SLI connector is only used with GeForce 6600 GT products and above.
* Select add-in cards support NVIDIA SLI. Look for NVIDIA-SLI certified add-in cards when making a purchase.

Optimized Games

NVIDIA® SLI™ can be enabled for every gaming application. However, in order to provide the optimal 'out-of-box' experience for its customers, NVIDIA has also created an extensive set of custom game profiles which enable SLI automatically and optimize scaling performance. The full list of these optimized applications is shown below:

http://www.slizone.com/object/slizone_game.html

SLI Application Profiles: How to Guide

NVIDIA SLI application Profiles using Coolbits*:
NVIDIA has created an extensive set of optimized application profiles which enable games to run automatically and optimally in SLI mode. There are currently over 100 of these NVIDIA pre-defined profiles.
Answering the needs of the SLI community, NVIDIA has also enabled its customers with the ability to create their own SLI application profiles. 

Follow the instructions below to create a new SLI Application profile or modify an existing one using Coolbits*.

http://www.slizone.com/page/slizone_appprofile.html

FAQ SLI (I)

What is NVIDIA SLI? How does it work?
NVIDIA® SLI™ (Scalable Link Interface) is a high-performance technology that intelligently combines and scales graphics performance and visual quality by having multiple NVIDIA GPUs in a single system. SLI Technology can scale both geometry and fill rate performance for two GPUs.

How is SLI different from competitive product offerings?
SLI takes the PCI Express multi NVIDIA GPU configuration to the next level by designing a family of GPUs that feature intelligent patent-pending hardware and software technology. The result is never-before-seen performance on PCs and workstations.
 
Do you have dedicated hardware for NVIDIA SLI or is it just software?
We have dedicated scalability logic in each GPU and a digital interface between GPUs to help enable this logic. In addition, we have a full software suite of advanced rendering algorithms that provide the best image quality.

How much of a performance increase will I see with SLI technology?
The amount of performance improvement will depend on the application and its ability to scale. Several of today's hottest games see a full 2X increase in performance. In general, applications running at higher resolutions with higher image quality settings will benefit most.

How does this technology differ from 3dfx's SLI?
NVIDIA SLI differs in many ways. First, 3dfx SLI was implemented on a shared bus using PCI. The PCI bus delivered ~100MB/sec. of bus throughput, while PCI Express is a point-to-point interface that can deliver ~60x the total bandwidth of PCI. Second, 3dfx SLI performed interleaving of scan lines, and combined in the analog domain, which could result in image quality issues due to DAC differences and other factors. 3dfx Voodoo technology also only performed triangle setup, leaving the geometry workload for the CPU, hence 3dfx SLI only scaled simple texture fill rate, and then used inter-frame scalability. NVIDIA SLI technology is PCI Express based, uses a completely digital frame combining method that has no impact on image quality, can scale geometry performance, and supports a variety of scalability algorithms to best match the scalability method with application demands.

Does SLI work on AGP?
No. SLI is designed for PCI Express.
 
How does SLI work on PCI Express?
SLI is designed for PCI Express. This new bus has superior bandwidth (two to four times AGP 8X), support for isochronous data transport, and the capability to drive multiple high-speed graphics devices. AGP 8X was limited to one high-speed graphics device and was not a good candidate for SLI.

FAQ SLI (II)

What operating systems are supported with SLI Technlogy?
SLI Technology supports 32-bit and 64-bit Windows XP.

What applications are supported with SLI Technology?
SLI can be enabled for every gaming application, providing either performance scaling results through AFR or SFR rendering modes or increased visual quality through the SLI Antialiasing mode. In order to provide the optimal 'out-of-box' experience for its customers, NVIDIA has created an extensive set of optimized game profiles which enable SLI automatically. The full list of these SLI-optimized games can be found here. For applications not found in this list, simply follow these quick instructions to set up a new game profile to enable SLI. Information about Workstation application support can be found here.

Why don't all games scale?
Applications which tax the GPU will see tremendous performance improvements of up to 2X with SLI technology. Most of today's hottest games and as well as next generation games fall into this category. However, some applications, typically older generation applications, are limited by factors other than the GPU's processing power. The most common limitation is an application that is CPU bound. If an application becomes CPU bound, no additional graphics power can improve performance. This situation is most common at low screen resolutions like 1024x786 with no additional functionality turned on. Turning on Antialiasing and Anisotropic Filtering, or switching to higher resolutions, can often move the bottleneck back to the GPU. For CPU bound applications, NVIDIA offers a new SLI rendering mode called SLI Antialiasing. This rendering mode allows customers to enable SLI8x or SLI16x antialiasing and enhance the visual quality of any gaming application.

What is SLI Antialiasing?
SLI Antialiasing is a new standalone rendering mode that offers up to double the antialiasing performance by splitting the antialiasing workload between the two graphics cards. When enabled, SLI Antialiasing offers 2 new antialiasing options: SLI8x and SLI16x. In the current driver, this rendering mode can be enabled by following these quick instructions. The next driver release will make this rendering mode a permanent part of the NVIDIA control panel. More information about SLI Antialiasing can be found here.

Is NVIDIA working with Developers on SLI application support?
Yes. NVIDIA is actively working with developers and educating them so that their titles can benefit from SLI as much as possible. By developing future titles on SLI technology, game developers are able to optimize their titles for SLI configurations. Additionally, the performance of SLI today gives developers a glimpse of how tomorrow's single GPU systems will perform. This allows them to tune for all elements of the system including CPU utilization. See what the developers are saying about SLI here.

How many monitors are supported with SLI in Multi-GPU mode?
When in Multi-GPU mode, SLI currently supports one monitor. When in Single-GPU mode, users have the ability to use up to 4 monitors using nView Multi-Display Technology and Windows XP Dualview.

SLI-Drivers