No SLI connector on the GTX 1060. Image credit: PurePC via VideoCardz.com. 

Graphics specialist NVIDIA (NVDA 3.71%) is expected to launch its next generation mid-range desktop graphics processor, known as the GeForce GTX 1060, later this month. Over the last week or so, there have been quite a few leaks about the 1060, revealing many of its details.

Interestingly, graphics card focused website VideoCardz.com, has another tidbit about the 1060 that's worth taking a closer look at.

No SLI for the 1060

Apparently, website PurePC leaked some images of NVIDIA's own GeForce GTX 1060 card design (likely to be marketed as the GTX 1060 Founders Edition). VideoCardz observed that the images of the 1060 show a lack of what is known as an SLI connector.

SLI, for those of you unfamiliar with the term, is NVIDIA's technology to allow a user to add multiple graphics cards to a system in order to boost performance beyond what a single card can deliver. Multiple cards are physically connected to each other using what NVIDIA is called an SLI Bridge.

Without a physical connector on the 1060, multiple 1060 cards cannot be connected by an SLI bridge.

The business rationale

If the GeForce GTX 1060 is priced at around $299 as rumors suggest, and if the leaks are correct in that it offers performance equivalent to a GeForce GTX 980, then it's not hard to see the business case for not including SLI on the 1060.

When the company announced its flagship GeForce GTX 1080, it said that the performance of this card was faster than two GeForce GTX 980s in SLI. So, NVIDIA's argument is likely to be along the lines of, "if you want the performance of two GeForce GTX 1060s in SLI, just buy a GeForce GTX 1080."

NVIDIA's gross profit margin percentage on the sale of a single GeForce GTX 1080, rather than two GeForce GTX 1060s, is almost certainly higher. Not only is a single 1080 card almost certainly cheaper to manufacture than dual 1060s, but NVIDIA's Founders Edition 1080 sells for $699 -- about $100 more than what two 1060s are rumored to sell for.

The technical rationale

Although it's easy to see why NVIDIA would prefer to sell customers one 1080 over two 1060s, there's also a good technical rationale for trying to push customers to get a single 1080 over dual 1060s.

NVIDIA recently killed off support for three-way and four-way SLI, which the company claimed was due to the fact that "it is becoming increasingly difficult for these SLI modes to provide beneficial performance scaling for end users."

Indeed, even two-way SLI is a challenge to extract performance from. In TechPowerUp's review of the GeForce GTX 1080 in two-way SLI, the site reported a performance increase of 52% at 4K resolution over a single GeForce GTX 1080 across its test suite. Stripping out games that don't scale with SLI yielded an average of 71% uplift over a single 1080 at 4K.

When SLI works, it's nice, but when games can't utilize multiple GPUs, the extra money spent on additional graphics cards goes to waste and could have been better spent buying a faster, single graphics processor.

In other words: NVIDIA likely sees SLI as only making sense when one needs performance that a single high-end graphics card simply cannot deliver.