What Is SLI and How Does it Work? List Of Compatible SLI Cards 2021


As a new PC gamer, one of the most important things you need to know is what SLI is. It stands for Scalable Link Interface and was created by Nvidia in 2002. This article will first go over what SLI does, then show a list of compatible cards. Finally, we'll discuss how SLI works and provide an Nvidia SLI compatibility guide.

What is SLI and why should We care about it?

  • SLI stands for Scalable Link Interface.
  • It allows the use of two Nvidia graphics cards in a computer to work together, doubling rendering performance.
  • The technology is called "SLI" because it was originally developed by Nvidia; this term has since become synonymous with any multi-GPU solution that uses NVIDIA chipsets and drivers.
  • Some games may offer support for this technology as an option or at higher settings than what they would normally run on one card alone, while others don't have anything specific to do with SLI capabilities directly but will still be more demanding due to having been designed around the expectation that SLI might exist (e.g., by creating high visual complexity). In either case, if SLI is supported by the game and enabled in the driver, it will not offer any performance improvements if both cards are being used to render a single frame.
  • Where SLI offers an advantage is when rendering frames for two different monitors with one graphics card each.
  • The SLI technology can also be applied to three or four Nvidia graphics cards - a "triple" or "quadruple SLI" configuration respectively; this would allow increased video memory (to support more intense resolutions), as well as triple/quadruple rendering power at higher resolutions (e.g., 5760x1080).
  • However, if you have Triple SLI your PC may need some serious cooling because that setup requires about 240 watts of electricity just to operate.
  • To disable SLI, you need to install the nvlddmkm Windows driver instead and then find that SLI option in your graphics card's control panel.

How does SLI work?


If you have only one GPU, then that GPU will correspond with either A0:B0 (PCI Bus 0) in order of connection or DVI/HDMI output port number if using onboard graphics instead of discrete graphics cards.

If both CPUs are installed onto your motherboard, then there would be no need for SLI because connecting two GPUs would not increase performance any further from just having one.

In order to enable SLI, you would need to buy a second GPU and connect the power supply for both cards together and then install them into your motherboard in a similar fashion as if it were one card (A0:B0 or DVI/HDMI).

The dual graphics cards will use one of two methods to trade data back-and-forth between each other on what is called an "SLI bridge." The first method uses PCI Express lanes which are split by using ferrite cores that act as traffic cops.

This takes up less space than the alternate option which splits up groups of four PCIe lanes through a small printed circuit board with sixteen connectors on it.

How Much Faster Is SLI For Gaming?

One of the most common questions that gamers ask is how much faster would they be able to play games if they had two graphics cards instead of one. The answer depends on a few factors, including what kind of computer you have and which type of SLI configuration your running (SLI or CrossFire). Below, we will examine how the different configurations vary in their speed.


This configuration consists of four graphics cards in the same computer plugged into separate PCI Express slots and with a minimum requirement of two monitor output connectors for up to six monitors all configured as 2560x1600 resolution screens.

It offers more graphical detail than Dual SLI because it supports up to 12 monitors simultaneously on a system that can be run on any modern motherboard design by plugging secondary GPUs into near PCIe slot counterparts.

Unlike Dual SLI, this setup does not need extra power from an additional PSU due to its greater capability and freedom for customizations such as higher refresh rates (144Hz) using NVIDIA's ULPS technology which is unavailable via Nvidia's Surround multi-monitor mode.

Dual SLI:

This configuration consists of two graphics cards in the same computer plugged into individual PCI Express slots, but only one monitor output connector for less screen estate than Quadfire.

It offers good graphical detail because it supports up to six monitors simultaneously at 2560x1600 resolution as long as all screens are properly configured.

This system can be run on any modern motherboard or desktop case design by plugging the secondary GPU into another PCIe slot near its primary counterpart.

However, this setup does not provide nearly enough horsepower for some high-end games such as Skyrim with an ENB preset, or the Battlefield series at maximum settings.

Why do I need to use SLI if my computer has a built-in graphics card? 

One reason you might use SLI is for an integrated graphics card. If your computer has both onboard and PCI express slots, it's usually best to plug in the high-powered card as close to the CPU as possible for better performance.

It also can help avoid some system crashes when using demanding software like games or video editing programs by spreading out processing power more evenly between two cards instead of loading all that work onto one piece of hardware.

The other major reason is that newer computers often have built-in graphics chipsets which do not support DirectX 12 technology required for many modern games--a game will only run properly if they're connected through SLI rather than just the motherboard’s GPU (graphics processing unit).

That said, we’ve outlined a number of drawbacks to utilizing this setup. First and foremost, it's expensive; you need two powerful cards to see much improvement in performance over one card alone.

econdly, these types of setups are more difficult to upgrade as your needs change because adding another card means replacing both at once or finding an old used card on eBay.

The good news is that most new gaming PCs come with dual GPUs preinstalled—if yours doesn't, you can purchase a graphics card to upgrade it.

What Is Needed To Run SLI?

  • To run SLI, you need two video cards.
  • The second video card needs to be of the same level as your primary GPU.
  • You can also choose different models that are from the same manufacturer and generation (i.e., NVIDIA GTX 1080 Ti) or upgrade down a model series (i.e., GeForce GTX 1080).
  • In order to install both graphics cards in one computer system, it's best if they're identical models with identical power connectors so they'll fit into matching slots on the motherboard without blocking each other off. If not, use an adapter bracket such as this EVGA Graphics Card Adapter Bracket Pair. Make sure the intake and exhaust vent are spaced correctly by positioning them vertically. Do not place them in a horizontal arrangement, as this will restrict airflow.
  • Once your graphics card is installed in the PCI-E slot, plug the power cables into both cards and connect them to a compatible PSU (600W minimum). Turn on your computer system and you're ready for gaming.

SLI - Master-Slave Configuration


The SLI configuration provides high availability and load balancing. It also supports failover due to a host or storage failure with minimal impact on the applications that use it.

A pair of physical devices are configured as master and slave: computers, disks in a RAID array, network switches, etc. The primary unit has two functions: (a) respond to user requests for data, and (b) monitor its partner's status.

If the secondary device fails, then the primary takes over all responsibilities without interruption to end-users from either loss of service or downtime while reconfiguring itself automatically as needed .

If at any time there will be only one computer available (the original secondary), then we say that this system is in ' single-system image' or S.

SLI Bridges


SLI Bridges also known as a connector, SLI Cable, or SLI Bridge. These are used to connect graphics cards in a system with two slots for more than one card.

SLI Bridges allow the GPUs of an SLI system (in computers) to be connected together so that they can share data and thus process images on them both at once. This allows better use of processing power by utilizing each GPU's own memory but also uses up more valuable PC resources such as RAM.

The downside is lower performance per slot when using only one video card due to the inherent bandwidth limitations placed upon any single PCI Express connection versus what dual-slot systems offer.

Due to how much faster it would run if there were no bottleneck between the GPU's processors, SLI bridges are commonly installed into a system with two slots for more than one card.

This way, the GPUs are plugged into SLI Bridges and connected together through a data cable to allow each of them accesses to all of the system's resources.

The bandwidth limitations on any single PCI Express connection versus what dual-slot systems offer is an inherent problem that SLI bridges can't overcome; they do not increase performance per slot when only using one video card due to this limitation.

Any improvement from running in SLI mode comes as much from having some available extra processor power at your disposal as it does from your hard drive being able to serve up data faster since there is less work for it to do simultaneously across both graphic cards' processors than if you were just utilizing one GPU by itself.

There are three types of SLI Bridges:

  • Standard Bridge: This is a traditional bridge included with motherboards that support SLI up to 1920×1080 and 2560×1440@60Hz.
  • LED Bridge – SLI bridges are necessary for high refresh rate monitors and can only work if the GPU supports this as well.
  • High-Bandwidth Bridge or SLI HB Bridge  – This is an Nvidia exclusive bridge recommended for monitors up to 5K and surround gaming, but can be used in a 2-way configuration. An SLI HB Bridge is not available in 2-way configurations, so it’s only sold for 3 or 4 way setups.

Power Requirements


The power requirements for SLI are not as demanding. Users will need a minimum of 450 watts, but it is recommended to have at least 550 wattages per card if you want the full benefits of your graphics cards.

If you're using one or two GPUs in your system then that should be more than enough, and some users may even require less depending on their usage patterns.

Types Of SLI Modes

SLI mode

A mode for running two or more video cards in an Nvidia SLI configuration. This is the only mode that allows both cards to be used simultaneously and independently during operation.

Auxiliary SLI Mode

Enables GPU switching from one graphics card to another, typically done on laptops with multiple GPUs installed but not configured as a single system (e.g., laptop built around dual GeForce GTX 960M).

In this case, it may enable much higher performance levels than either of those individual devices can provide when utilized alone because they are able to run in parallel on separate parts of the screen rather than alternating every other frame between them like would happen under standard SLI operating rules.

Cinematic SLI Mode

This was the type of mode used for the first two Wipeout games. It does not use both cards simultaneously but instead alternates frames between them, simulating a dual-monitor display by having one GPU render an entire frame before passing it to the other card to do likewise with its own frame so that they end up alternating in sync and synced with your monitor's refresh rate.

This can allow higher resolutions than standard SLI because each card is rendering half of the screen rather than every other single frame as in regular SLI Mode.

however, this will also divide available framerate bandwidth into halves meaning that overall performance may be lower if you're only interested in high resolution and maximum frame time stability.

  • Context Priority: One or more GPUs are allocated priority to the currently active window, which may be a video game or program.
  • In this mode, all GPUs are rendering frames in turn with idle time spent waiting for their input to become available again. In other words, if one GPU is running at 100% utilization then SLI will by default not boost it further but instead allocate that output to a second card idling on 0%.
  • A potential upside of context priority is that it can allow higher resolutions than standard SLI because each card is rendering half of the screen rather than every other single frame as in regular SLI Mode; however, this will also divide available framerate bandwidth into halves meaning that overall performance may be lower if you're only interested in high resolution and maximum frame time stability.


SFR is the same single GPU running in SLI mode but with some form of vertical sync enabled. This can be more demanding on both GPUs and your system than standard SLI because it must render every other frame twice to avoid frame time stability issues.

However, this also makes SFR less prone to micro stuttering when compared to regular SLI Mode which may benefit those sensitive or noticing that issue during gameplay.

SLI compatibility

SLI compatibility has not been proven at all for processors such as AMD's Ryzen series CPUs while NVIDIA does have a history of supporting Intel's Core iX family including their upcoming Coffee Lake release too (unlike AMD) so if you're looking forward to trying it out new technology like these then there are tradeoffs and considerations worth bearing in mind before deciding on which hardware manufacturer you go with.


Multi-Monitor splits GPU rendering between multiple screens to increase framerate and decrease latency from display output; this can cause less processing power than going with one monitor but has been shown to have positive effects in certain games like Overwatch where it reduces input lags when compared against using just one screen too in certain situations.

SLI Features

 The following features are provided by SLI:

  • Physically Redundant - Data is mirrored to two or more devices for protection against hardware failure. A single point of hardware failure can be tolerated with no loss of data because the slave automatically takes over in this situation. This feature also allows the system administrator to focus on managing a smaller number of disks while satisfying demands for growth in disk space; when additional capacity is needed, an identical disk can simply be added as a replacement without interrupting operations from either end-users or other applications using that storage resource.
  • Load Balancing - SLI provides efficient load balancing since all operations execute on both units which means they can be balanced across the two units.
  • Parallel Processing - SLI allows operations to execute on both units in parallel, which makes it possible for a system with fewer than two disks to achieve higher disk throughput and lower response time by using I/O Bandwidth more efficiently or by processing requests from multiple applications simultaneously.
  • Hot Spare Disk(s) Protection - A hot spare is an extra drive installed into the enclosure that can "take over" if one of the other drives fails. If this happens, then SLI provides protection against data loss as long as there are at least three good disks in the storage pool when configured as RAID-50 (RAID level 50). In every other configuration, including RAID-0+spares, a failure of a single disk will lead to data loss.
  • Disaster Recovery Protection - SLI provides disaster recovery protection as long as there are at least three good disks in the storage pool when configured as RAID-50 (RAID level 50). In every other configuration, including RAID-0+spares, a failure of a single disk will lead to data loss."
  • Hardware Requirements: SLI works with any hardware that meets the minimum requirements below. However, it is recommended to have two or more "identical" systems connected together via either dual Ethernet connections on both ends for redundancy; Windows Server 2008 Standard Edition 64bit DVD and license key; Client computer running Microsoft Office 2007 Professional Plus 32 bit version installed from original media using CD/ DVD; Client computer running Microsoft Office 2010 Professional Plus 32x installed from original media using CD/DVD.
  • Software Requirements: SLI is a software-only solution that does not require any additional hardware. It can be deployed on Windows Server 2008 Standard Edition 64bit, Windows Vista Business or Ultimate Edition (32 bit and 64bit), as well as the latest versions of Linux distributions like CentOS, RedHat Enterprise Linux, Ubuntu 12.04 LTS Desktop x86_64 (Server version is available here).
  • The bandwidth requirement for synchronization between sites: 500Kbps per site with latency below 50ms over WAN.

Common reasons for using SLI

An SLI setup can be used for heavy-duty graphics processing. It is most commonly seen in gaming PCs, but it also has other uses such as the use of two or more GPUs to handle rendering tasks related to image and video editing.

The first reason one might want an SLI configuration is if they need a stronger GPU than what their single card can provide (a two-card setup). Another way to get better performance out of your PC with this type of configuration would be if you wanted live streaming capabilities on platforms like Twitch while playing games.

Note that this isn't very common unless you're really into saving time by not having to edit the footage after recording gameplay because everything will render directly from the source material without any additional work required.

Types of cards that can be used with SLI 

Different types of cards can be used with SLI.

  • Some video cards have a minimum requirement that there must at least two graphics card slots on the motherboard. This is known as 'SLI compatible'. If this requirement does not exist, then the computer will only run one slot which is SLiNcompatible or Nvidea duel GPU supported (DGP).
  • The other type of graphic card includes ones without any restriction in terms of number for use and they are also called "Non - SLI Compatible".

This means if you want to install multiple different graphic cards into your system, it has to be either DGP or SLI compatible. There's no way around this limitation unless you're getting some fancy custom computer.

For SLI Compatibility, what you need?

What you need to know for SLI compatibility:

  • The graphics card needs a power connector or an ATX motherboard. There are two main types of cards, either with three connectors (two PCIe and one dual-link DVI) or four connectors (three PCIe and one HDMI).
  • For those who have the most recent NVIDIA GeForce GTX 800 series in their systems, they will find that these come with the newer PCI Express standard which is required if using SLI.
  • For those who have a ZOTAC GeForce GTX 750 Ti, it has two HDMI ports that can be used for display outputs alongside DVI or DisplayPort connectors.
  • Cases also need to support dual graphics cards with extra power cables, more cooling fans as well as longer slots for mounting them all inside.
  • A higher-quality PSU is needed too - 500W should suffice but there will be no room left over after adding an additional card so make sure any new model bought exceeds its requirements by at least 20%.
  • Finally don't forget that drivers must work together across both GPUs before using SLI and that SLI performance is only as good as the slowest card.

When should I buy a new GPU instead of adding another one to the system?

The answer is more complicated and nuanced. It depends on how you plan to use your PC, what you are doing with it, how much money do you have for upgrading, etc. But there are some general guidelines that can help in the decision-making process:

  • First thing is - if your current graphics card has been released more than a year ago (exceeding this time period will be even better), then chances are high that performance improvement by installing a second graphics card will not be noticeable enough and we may suggest getting new GPU instead of an additional video card.
  • The second consideration would be the pricing difference between two cards which could range from $60-$100. If you are on a tight budget, and the price difference is too large - then it might be more reasonable to get just one card.
  • The third thing that should help with your decision-making process would be how you plan to use your PC: if you are not playing games or running professional applications (e.g., CAD software) but rather do office work like browsing websites and editing documents - in this case, we could suggest buying a single video card for $200-$400 (depending on performance level required). But if gaming is an important part of your life and activities, even though there's only one chance in three that adding another graphics card will decrease lag time by up to 30%, we may advise getting a new GPU instead of a second graphic.

Which Graphics Card Support SLI

GeForce RTX 2080 Ti
GeForce RTX 2080 SUPER
GeForce RTX 2080
GeForce RTX 2070 SUPER
Nvidia Titan Xp
GeForce GTX 1080 Ti
Nvidia Titan X
GeForce GTX 1080
GeForce GTX 1070
GeForce GTX 980 Ti
GeForce GTX 980
GeForce GTX 970
GeForce GTX 960
GeForce GTX 950
GeForce GTX 780 Ti
GeForce GTX 780
GeForce GTX 770
GeForce GTX 760 Ti
GeForce GTX 760
GeForce GTX 690
GeForce GTX 680
GeForce GTX 670
GeForce GTX 660 Ti
GeForce GTX 660
GeForce GTX 650 Ti BOOST
GeForce GTX 480
GeForce GTX 470
GeForce GTX 465
GeForce GTX 460
GeForce GTX 460 SE
GeForce GTS 450
GeForce GTX 555 (OEM)
GeForce GTX 560 Ti (OEM)
GeForce GTX 560
GeForce GTX 550 Ti
GeForce GTX 590
GeForce GTX 660
GeForce GTX 560 Ti
GeForce GTX 545 GDDR5
GeForce GTX DDR3
GeForce GTX 570
GeForce 9800 GT
GeForce GTX 580
GeForce 9600 GT
GeForce 8500 GT
GeForce 8600 GTS
GeForce 8600 GT
GeForce 8400 GS
GeForce GTX 275X
GeForce GTS 150
GeForce GT 130
GeForce GT 120
GeForce GTS 250
GeForce GTX 285
GeForce GTX 295
GeForce GTX 295
GeForce 8800 ULTRA
GeForce GTX 280
GeForce 8800 GTX
GeForce 9800 GX2
GeForce GTX 260
GeForce 9400 GT
GeForce 9500 GT
GeForce 9800 GTX
GeForce 9800 GTX+

Frequently Asked Question

Question: What is SLI and how does it work?

Answer: A short "scalable link interface", a technique that enables two or more Nvidia graphics cards to be combined in the same computer system. This allows them to use their respective processing power on one large image, such as with photoshop.

By dividing up the workload, both of your GPUs can handle bigger tasks without slowing performance down.

Question: Is SLI only compatible with NVIDIA graphic cards?

Answer: No, AMD also has its own version called Crossfire which performs similar functions but uses different hardware components than SLI. However, if you have an AMD card then this would not affect compatibility between AMD Radeon video cards and other non-AMD parts installed into the system.

Question: What is the performance difference between a single GPU and SLI?

Answer: A system with one GPU can only handle tasks by using all of its computing power, while two GPUs in SLI mode divide up the workload to free up more resources for each task.

Therefore, if you have two similarly powerful cards then your graphics will be twice as fast when running at double speeds on both video output ports rather than just one port on a single card.

In other words, it's capable of doubling speed without any need for overclocking or upgrading existing hardware components such as RAM or processors that are already installed into the computer system.

Question: Is SLI compatible with all video games?

Answer: Many of the newer titles are built to support SLI, and there is a list of supported cards on Nvidia's website.

Question: What does SLi do for my GPU? Does it increase the speed or make it stronger?

Answer: A system with one GPU can only handle tasks by using all of its computing power while two GPUs in SLI mode divide up the workload to free up more resources for each task. In other words, it's capable of doubling speed without any need for overclocking or changing other settings.


SLI means "scalable link interface" which is a graphic card configuration in computers that allows the usage of two (or more) video cards for rendering graphics on one computer monitor.

You can configure your computer to use either an NVIDIA GTX 970, AMD Radeon RX 480, NVIDIA GTX 1070, or AMD Vega 64 as the primary GPU with at least one other from these options as secondary GPUs; GeForce 750 Ti - TITAN X Pascal Edition Titan V 12GB HBM Memory – Quadro P5000 32 GB GDDR Interno 500W 80 Plus Platinum Power Supply.

I hope you enjoyed this blog post and found it informative.