Multi-GPU setups have always been the dream of PC enthusiasts, which allows them to experience next-generation performance before the next generation rolls around while at the same time making their PC look like a powerhouse churning out “mad” frame rates.
Pooling graphics card resources and getting visuals in 4K or even 8K has made enthusiasts stuff their PCs with more and more graphics cards.
But just stuffing your PC with more cards will not do the job, and you need some technology for all the GPUs to talk to each other, and that’s where SLI and Crossfire come in.
Everyone and their mother knows about the multi-GPU configuration from Nvidia called Scalable Link Interface or SLI.
However, Team Red’s flavor of the same technology is called Crossfire. So, in this article, we will be talking about What Crossfire is and how it is different from Nvidia’s SLI.
What Is AMD CrossFire?
AMD’s Crossfire is the technology that allows two AMDs GPUs to be used in tandem, thereby pooling their resources and increasing the gaming performance of the PC. However, there are certain limitations, and you cannot just pool any graphics card willy-nilly.
For CrossFire to work, you need two AMD graphics cards from the same architectural generation. However, you are free to mix and match when it comes to clock speeds and memory size. So, in theory, you can Crossfire an RX 550 with an RX 580 and get some performance increase.
How Does AMD CrossFire Work?
Suppose you have two Nvidia GPUs like the GTX 1070 and the GTX 1080. You cannot SLI them as they are not compatible with each other.
While Nvidia only allows you the freedom to pick between different card vendors and clock speeds but restricts you to the same graphics card.
Meanwhile, AMD’s multi GPU solution is a lot more “loosey-goosey” and, in my opinion, more consumer-friendly. As long as you have two AMD graphics cards that belong to the same architecture family, you can go crazy.
Pair the lowest-end AMD GPU with the flagship one, and they are going to work as expected. Unlike SLI, you also do not need a connector to pair them together as crossfire cards can communicate using the PCI slots.
What Crossfire does is that it pools the resources of the two AMD GPUs and combines the processing power of the GPUs in a Master-Slave configuration. This means that one card will act as the Master card while all the following cards will serve as the slave cards.
The Master cards will receive the processing output from the slave cards and create the resulting image. There are two modes of graphics cards in Crossfire that work with each other.
Split Frame Rendering
In Split Frame rendering, every card is assigned the work on different parts of the frame to be rendered and sent to the master card to be compiled.
The master card, after compiling the resulting frames, display the images on the screen. Crossfire’s one-way graphics card pools its resources and gives you more performance.
Alternate Frame Rendering
Another graphics rendering technique done by cards in Crossfire is alternate frame rendering. As the name suggests, this type of rendering renders every alternative successive frame.
The Slave-Master configuration remains the same; however, each card renders separate frames and combines them to form the image you see on the screen.
The Results And Gains
The results and gains of a multi GPU setup using Crossfire can be somewhat complicated as not all games run at double the performance, nor do you get double the frame rates.
There is a lot of testing and coding required for a game to scale properly on setups like these, and developers know that a tiny subset of the population is rocking multi GPU configurations; therefore, they do not even bother with doing the necessary work.
In some cases, games even perform worse in Crossfire which is why one needs to keep their expectations realistic, and due diligence is required before shelling out the money for multiple GPU setups.
I have taken the liberty of including some benchmarks from “Hardware unboxed” in some popular titles with the RX 480 in single card and crossfire configurations. All games were played at 1440p in Ultra quality settings.
List of CrossFire Compatible Cards
Here is the list of CrossFire compatible cards from AMD. Keep in mind that you should run only those cards in Crossfire that belong to the same architectural family.
- Radeon RX Vega 64
- Radeon RX Vega 56
- Radeon RX 590
- Radeon RX 580
- Radeon RX 570
- Radeon RX 560
- Radeon RX 480
- Radeon RX 470
- Radeon RX 460
- Radeon R9 380X
- Radeon R9 295X2
- Radeon R9 290
- Radeon R9 280X
- Radeon R9 280
- Radeon R9 270X
- Radeon R9 270
- Radeon R7 265
- Radeon R7 260X
- Radeon R7 260
- Radeon R7 250X
- Radeon R7 250
- Radeon R7 240
- Radeon HD 7970
- Radeon HD 7950
- Radeon HD 7870
- Radeon HD 7850
- Radeon HD 7770
- Radeon HD 7750
- Radeon HD 6990
- Radeon HD 6970
- Radeon HD 6950
- Radeon HD 6870
- Radeon HD 6850
- Radeon HD 6790
- Radeon HD 6770
- Radeon HD 6750
- Radeon HD 5970
- Radeon HD 5870
- Radeon HD 5850
- Radeon HD 5830
- Radeon HD 5770
- Radeon HD 5750
- Radeon HD 4870 X2
- Radeon HD 4850 X2
- Radeon HD 4890
- Radeon HD 4870
- Radeon HD 4850
- Radeon HD 4830
- Radeon HD 4770
- Radeon HD 4670
- Radeon HD 4650
- Radeon HD 4550
- Radeon HD 4350
- Radeon HD 3870 X2
- Radeon HD 3870
- Radeon HD 3850 X2
- Radeon HD 3850
- Radeon HD 3650
- Radeon HD 3470
- Radeon HD 3450
What Is Hybrid CrossFireX Technology?
AMD’s Hybrid CrossFireX Technology allows the discrete AMD GPU and AMD APU to form a crossfire and pool their resources, thereby increasing the graphical performance of the machine. This feature can be handy to the people who primarily used APUs before getting themselves a discrete GPU.
This technology effectively lets you Crossfire without needing double GPU configuration if you own an APU. In the good old days, I used to rock an A8 APU and did most of my gaming on there.
I then saved up enough to get myself an HD 6570. I wish I knew I could Crossfire them before as I was not very computer literate back then; however, I do remember getting more performance than the benchmarks suggested, so maybe it happened automatically.
Anyways, I digress. I did manage to get some numbers for you, which are straight from some online sources. So, an AMD A8 APU was paired with an HD 6670, and as a result, the performance was doubled by precisely 123%.
I take these numbers with a grain of salt; however, even if you got a fraction of this performance, then kudos to AMD for the Hybrid CrossFire technology.
CrossFire Vs SLI: Similarities And Differences
Let us first discuss the Similarities between CrossFire and SLI. First and foremost, both of these technologies allow you to have multiple GPU setups. You can have two, three, and even four graphics cards on your PC.
The Second similarity between them is that both work in the same Master-Slave configuration. One GPU acts as the Master while the remaining act as the slave, and there is only one-way communication between the Master and slave.
The last similarity between the two is the rendering modes discussed earlier, called Split frame rendering and Alternate frame rendering.
Now onto the differences between CrossFire and SLI. The first and the most significant difference between the two is that Crossfire allows you to mix and match GPUs from the same architecture type while SLI only allows for Multi GPU configuration of the same graphics card. So, an AMD RX 570 can be Crossfire with an AMD RX 580, while you will need two GTX 1070s for an SLI configuration.
The second difference is the connector. SLI requires a connector called “SLI bridge” for the GPU to communicate between them, while CrossFire uses the PCI express for inter GPU communication. So, getting yourself another AMD card is enough, and you will not need anything else to use Crossfire.
Next, SLI requires particular motherboards with SLI certification to work, while CrossFire is available on most motherboards. Even business class motherboards are seen carrying around a crossfire certification.
CrossFire also allows for APU compatibility using Hybrid CrossFireX technology, while SLI does not support APU, effectively letting its resources go to waste.
The final difference lies in that SLI supports games to be played in windowed and full-screen mode, while CrossFire only does Full-screen mode.
Some Major Problems With Multi-GPU use?
Multi-GPU setups can make sense for some people who want to experience next-generation performance right now; however, there are a lot of problems associated with it which has forced many enthusiasts to go back to single cards configuration.
First and foremost, the biggest problem is that not every game supports a multi-GPU configuration. There is a lot of testing and coding required from the developer to make their game multi-GPU compatible.
However, many developers do not bother with it as only a small subset of people use such configurations. This is why many games do not scale well to multi-card setups and, in some cases, even perform worst.
Another problem with multi-GPU setups is the law of diminishing returns which sets as you add more and more GPUs to your system.
Adding more GPUs to your system will not multiply the graphics performance of your PC, which is why according to many enthusiasts, multi-GPU setups are dubbed as a waste of money. NVLink tries to solve this problem; however, that is a topic for some other day.
What’s Next For AMD CrossFire?
The future of CrossFire is currently uncertain as AMD has confirmed that Crossfire is no longer a focus for the way back in 2019. So does this mean that Multi-GPU setups and configurations are dead?
Well, not necessarily because Nvidia has released the NVLINK, which tries to solve most of the problems of SLI. One of the biggest problems they solved was increasing the bandwidth cap from 2 GB to 150 GB and allowing for two-way communication in cards, negating the concept of master-slave card configuration.
If Nvidia’s NVlink is popular with the consumer and renews interest in multi-GPU setups, then AMD will work on their flavor of NVlink, which does almost the same thing along with some of the advantages already present in Crossfire. If AMD succeeds in doing this, we might see a resurgence of multi-GPU setups in the enthusiast space.
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This wraps up everything I wanted to say about Team Reds’ flavor of multi-GPU solutions. CrossFire is undoubtedly a more consumer-friendly solution, not only for the enthusiasts but also for 16-year-old me who was running his games with an APU and an AMD GPU without even knowing sometimes.
Even though CrossFire can be great sometimes, it has many problems common to multi-GPU configurations, so right now, I would say that it is better to avoid such configurations and stick to a more powerful single GPU.
However, you never know; we might see a resurgence of Crossfire, and AMD might even be working on an upgraded version of this technology, so all we need to do is sit and wait and hope for the best.
Frequently Asked Questions
#1 – Is dual GPU dead?
This depends on who you ask. There has been a decline in dual GPU setups; however, Nvidia’s NVlink might revive them if they become more popular in the enthusiast space. In my opinion, it is safe to say that dual GPUs are in a coma.
#2 – Does CrossFire double VRAM?
No! CrossFire does not double your VRam. Only the VRam from the Master GPU is accessed during the workload, so if you have two GPUs with 8Gb Vram each, only 8 Gb is available to you during gaming.
#3 – What is Hybrid CrossFire?
Hybrid CrossFire allows your AMD GPU and AMD APU to work in tandem or Crossfire. This allows the two to pool their graphical resources and gives you more performance.
#4 – Can You run 2 GPUs without SLI?
You cannot run two identical Nvidia GPUs without an SLI bridge. However, if you own two AMD GPUs from the same architectural family, you can run them in Crossfire as they communicate through the PCI express.
#5 – What is CrossFire ready?
CrossFire ready is usually written on motherboards and AMD GPUs as a certification to show that they are compatible and ready to be used in crossfire mode.
#6 – How do I turn off CrossFire?
Head to “AMD Radeon settings” by right-clicking on your desktop. Go to the “display settings.” In the left menu, click on “AMD Crossfire” and click on “disable AMD Crossfire,” and you are done.
#7 – Can I CrossFire AMD with Nvidia?
No, You cannot CrossFire AMD with Nvidia. You can only CrossFire AMD cards with other AMD Cards.
#8 – What is the benefit of CrossFire?
By using CrossFire, you can pool the graphical horsepower of multiple AMD GPUs in your computer, which will allow you to play your games on higher resolutions and frame rates.