Anyone familiar with multi-GPU rendering has heard the termSLI.
As the mainstream monitor resolution has grown, the decades-old SLI technology hasnt been able to keep up.
So what exactly is the NVLink & how is it any different than SLI?
What is SLI?
AMD also has an equivalent solution namedAMD Crossfirewhich works in a similar fashion.
This technology was first introduced to the public in 1998 by a company named 3dfx.
It was later bought by Nvidia & rebranded as SLI.
Additionally, those GPUs need to be connected via an external SLI bridge.
This scaling technology uses 5 rendering modes to proportionally divide rendering workloads among available graphics cards.
What is NVLink?
It is also bi-directional and works as a mesh.
So theres no GPU hierarchy in this technique.
It uses a wired-based communication protocol for a significantly advanced and faster GPU interconnection.
For consumer-grade products, you might only connect 2 GPUs via NVLink.
NVLink vs SLI: Which One is Better for Multi-GPU Rendering?
This resolves the bandwidth bottleneck of SLI, allowing the system to pool resources.
Another noteworthy difference between NVLink & SLI is thattheres no master-slave hierarchyin NVLink.
As a result, users can finally get the combined VRAM pool of all the GPUs.
As a result, if youre using two 11GB cards, you wont get a 22GB VRAM configuration.
Youll only have the master GPUs 11GB VRAM available for usage.
Not only that, the physical interface of NVLink is vastly different than the SLIs.
As we can see, the NVLink connector isthree times widerwith way more pins than the SLI connector.
Infact, NVLinks connector looks almost like a little PCI Express connector.
This actually has an underlying purpose, to create a mesh web link among GPUs.
Speaking of connectors, another major difference between NVLink and SLI is the connector bridge & its pricing.
NVLink bridge can cost up to 600$ compared to a high-end SLI bridge priced at 40 bucks.
Now that weve established the technical differences between the two GPU scaling technologies, which one is actually better?
Well, obviously the newer, more advanced one.
Hence, the performance boost of NVLink is significantly higher than traditional SLI which is perfect for high-end workstations.
But the ones that worked, managed to perform exceptionally well.
![nvlink-vs-sli-connectors]](https://10scopes.com/wp-content/uploads/2023/03/nvlink-vs-sli-connectors.jpg)
Additionally, GTX 1080Tis SLI setup failed to perform better than a single GV100 card.
But the NVLink managed to offer a significantly lower render time compared to all.
Now lets change our focus from productivity to gaming performance.
Still, I noticed a substantial performance gain while using NVLink over SLI.
So gamers across the world should double their GPU purchase to get these noticeable benefits of NVLink, right?
Barely any new game or software has support for SLI or NVLink.
Furthermore, most games straight-up drop performance when I ran them in an NVLink or SLI setup.
Such a lack of optimization can introduceGPU artifacting issuesfor various workloads.
Not to mention, general consumers arent willing to spend over 3000$ alone for the GPU segment.
Adding additional graphics cards prevents the graphics cards from getting thenecessary GPU clearancefor optimal cooling.
As a result, the internal temperature will start to rise & theGPUs might start to overheat.
This was the final nail in the coffin of multi-GPU scaling for general consumers.
Although, it is still supported in professional-grade Nvidia products like Quadro GPUs.
Hence, NVLink isnt really dead, yet.
Frequently Asked Questions
Is NVLink dead?
From RTX 4000 series & forward, Nvidia is no longer supporting NVLink on the consumer-grade GPUs.
NVLink is now only available for the Quadro lineup.
What GPUs support NVLink?
How many GPUs can SLI support?
Nvidias SLI technology can support up to four graphics cards.
But NVLink has started to make traction among professionals who need a hefty chunk of VRAM.
Now you know all the essential differences between NVLink and SLI.
Feel free to ask any query in the comment section below.
