Surely, you can install two or more RAMs into your system to maximize dual-channel memory and performance; it’s not that simple for a GPU. You can’t just install two graphics cards in your system and use the total VRAM.
Whether you use SLI or Crossfire, there are some protocols and requirements you must fill up to use those properly.
I’ll explain the SLI Technology and whether you need the same GPU to use SLI.
What is SLI?
SLI (Scalable Link Interface) technology connects two matching Graphics Cards to render better by sharing the workload across the unified multi-GPUs in a system. You can use multiple Graphics Cards in one system to extend the VRAM and the performance with SLI.In 1998, a company titled 3DFX released its VOODOO II Graphics Card with SLI technology. At that time, SLI was elaborated as Scan Line Interleave until Nvidia took over this technology.
Since the release of SLI, two technologies have been used to divide the workload between GPUs that are AFR & SFR. The AFR (Alternate Frame Rendering) splits the frames into even & odd numbers to share the workload between two GPUs.
Furthermore, the SFR (Split Frame Rendering) is a newer workload-sharing technique that lowers the latency while using SLI between Graphics Cards.
But the question remains: is SLI technology available for all GPU pairs?
The answer is a straight NO if you are thinking of pairing two different model GPUs. Because SLI is only available among the GPUs with identical GPU chips.
Check out the easiest way to check if GPU is working properly.
Why Do You Need Identical GPUs to Use SLI Technology?
You need the exact chipset-based Graphics Cards to use the SLI technology on your system. And the VRAM amount should be the same for adequate utilization of GPUs.
Although you can use SLI with two identical chipset GPUs of 8 GB VRAM & 12 GB VRAM, you’ll actually have a total of 16GB VRAM instead of 20GB.
Take the example of an RTX 2080 & an RTX 2080Ti with chipsets TU104 & TU102 due order. I couldn’t use these two cards for SLI because they own different chipsets.
Likewise, enabling SLI in BIOS between RTX 2060 GPU of 6 GB and RTX 2060 of 12GB won’t give you 18 Gigs total memory SLI support. Instead, it will work as 6 + 6 = 12 GB. But the good thing is that you can SLI with the same series graphics card, even from different vendors.
As an example, an ASUS ROG Strix GeForce RTX 3090 OC Edition graphics card is SLI compatible with EVGA GeForce RTX 3090 XC3 ULTRA GAMING card because they have the GPU chipset in common.
Eventually, you must have the RTX series GPUs to SLI because Nvidia doesn’t allow GTX series GPUs to be SLI Compatible. But it doesn’t indicate all RTX is SLI compatible either. SLI-compatible GPUs have SLI bridge connectors to sync.
Apart from these apparent conditions, some crucial and technical requirements are discussed briefly in a further section of the article.
Read more on what is Idle GPU temp?
What Are The Requirements for SLI on a Computer?
There are some add-ons and precautions, except for the requirements of an identical GPU Chipset. Skipping additive advice will affect your desired performance and hardware.
Your motherboard must support the SLI technology. And must have at least a 2X PCI-E x16 slot. For more than dual GPU SLI, enough PCI-E x16 slots are required in your motherboard. You can’t use any HUB to add more GPUs for SLI purposes.
Plus, the PSU(Power Supply Unit) must be above the gross maximum requirement according to the GPUs’ watt consumption. For instance, to use two RTX 3090 in your system, you’ll need up to 1200 watts, as each of the 3090 cards has a 750W requirement.
Since your rig will consume a hefty amount of watts, heat production is massive in such cases. You’ll definitely need proper ventilation with an overblown cooling system.
And most importantly, you’ll need an SLI bridge to connect two or more GPUs. The SLI bridge is a particular component required to attach to a unique mount other than the PCI-E x16 fin. Such a specific mount point is usually situated on the opposite side of the PCI-E x16 mount. You’ll spot this mount on the alternate edge of the power connection port.
Lastly, Direct X 12 or Vulkan API integration is natively required in games to utilize the SLI technology, as Nvidia stopped the SLI profile support officially on RTX 20 series and earlier ones on January 1, 2021.
So, new games are required to implement the SLI profile within the game. RTX 3060 came with an NVLink connection indicating the multi-GPU gaming is still on.
Since RTX 3090 doesn’t have SLI bridge data pins, you might think that NVLink is replacing the SLI technology. The doubt has been defogged in the following section.
Also read, how much GPU usage is normal for gaming?
Like SLI technology, the NVLink isn’t a full-fledged solution that can connect & sync between multiple Graphics Cards. It’s an updated version of an SLI connector.
Whereas an SLI bridge can only achieve 2 GB/s transfer speed, the NVLink hits up to a rate of 200GB/s.
But does it mean NVLink is replacing the SLI system?
No, it’s not replacing the concept of SLI so far. The branding SLI still stays the same as before. The only difference NVLink is bringing is the connection protocol of inter-GPU communication. Moreover, there is no such thing as a Master-Slave in SLI.
So, the NVLink is just a connector with a speedy transfer protocol. It isn’t actually replacing the SLI technology but enhancing it. To use this feature, your GPU must have the data pins needed for the NVLink connector.
Else you can dodge such complicated connections and choose AMD Crossfire technology, which serves the same purpose technically.
Does Crossfire Technology Work The Same as SLI?
As a counterpart of SLI technology, the ATi has released the Crossfire technology with the R400 series graphics. Later, the ATi company was taken over by AMD. The SLI technology serves a similar purpose but offers some flexibility.
While Nvidia locks things up to provide a consistent performance flow, AMD provides better flexibility.
For instance, AMD allows different cards from different vendors, models, series, and form factors that you can even Crossfire between integrated graphics with dedicated ones. The only requirement is architecture family matching between GPUs.
Moreover, the Crossfire technology does not need any dedicated connector like an SLI bridge or NVLink. Your motherboard’s PCI-e slot is enough for this operation, which is an excellent solution for a cleaner and more flexible setup.
Though Crossfire technology is the nemesis of SLI in the market, the purpose is the same. But AMD provides vast flexibility than Nvidia, which is a better approach from the perspective of budget users.
Because such consumers expect multiplying performance to be justified according to the expense, the further section will eradicate this uncertainty.
Does SLI Actually Multiply The Performance?
Technically, SLI does increase the performance of the graphics sector of a computer, but it can’t multiply on a significant level. You won’t achieve double or triple the overall performance as you add more VRAM.
Remember the power consumption rate discussed earlier?
More of the added Graphic Cards will consume lots of electricity and generate enormous heat but won’t perform accordingly. The performance-to-power consumption ratio is poor in this case.
In the worst-case scenario, the most recent GPUs can easily surpass the combined performance of two old-generation SLI-ed graphics cards.
Therefore, It’s not a worthy or cost-effective solution to gain performance because it adds a bit of thrust to performance but doesn’t justify the price and electricity cost.
Can I Play GTA V with SLI Technology?
The GTA V is one of the most optimized games that support SLI technology and is playable on a multi-monitor setup.
Can you dual GPU different GPUs?
You can use the dual GPU for a multi-monitor setup, but SLI requires the same GPU chip to operate.
How many GPUs Can you SLI?
You can SLI with 4 GPUs if your motherboard has four distinct PCI-E x16 GPU slots and SLI certification.
Does SLI improve FPS?
Although a handful of games increase FPS 2X. But most of the games increase FPS slightly.
How do I double my VRAM?
You can double your VRAM by replacing the old graphics card with a newer one of double VRAM.
Demand for SLI differs from user preferences because of its expensiveness; it is not a worthy solution in most cases. If money is not an issue, you can use this if you really crave performance.
Regarding such facts, Nvidia is slowly ditching this feature on the latest units and series of Graphics Cards. But Crossfire technology is still in a survival position because of the flexibility.
Comment below if you think it’s helping, and let us know if you still want to use SLI.