For years now, Nvidia has maintained that it's dual-GPU solution, SLI, is to be available only on motherboards that use its nForce chipsets. The release of Intel's forthcoming Core i7 processors (the new Nehalem architecture) poses some problems, though. Intel is moving the memory controller into the CPU with the Core i7, obviating the need for a north bridge.
The X58 motherboards that accompany the Core i7 launch later this year will be, at first, the only supporting platform for Intel's new CPU, and it will have enough PCIe lanes to provide two x16 graphics slots.
Nvidia's hand is sort of forced. There's no real need for an nForce chipset, yet if SLI is not supported on X58, their fastest enthusiast dual (or triple, or quad) graphics solutions won't work on what is sure to be the fastest CPUs around. The company has said it doesn't plan to make chipsets that work with the X58's Quickpath Interconnect (QPI), we assume due to unfavorable licensing terms.
Nvidia's solution? Enable and certify SLI on X58 boards—even with no nForce chip on board. Standard X58 motherboards are eligible for SLI certification. A dual-card SLI setup would have two PCIe x16 lanes, a board with three PCIe slots would have one x16 and two x8 slots, and four PCIe slots would be four x8s.
Of course, Nvidia would still love to sell some motherboard chips, and they'll find a way to do so on X58 motherboards. In three-slot and four-slot enthusiast level boards, Nvidia will sell the nForce 200 chip to board vendors essentially just to use as a PCIe switch—it will connect to the "Tylersburg" south bridge on X58 motherboards and switch one or two of the PCIe x16 lanes to two x16 lanes.
So how does this work? X58 motherboard makers will submit each board model to Nvidia for certification, which will take place in its Santa Clara lab. This is a for-pay certification program, not free—vendors must display the SLI logo on their boxes and marketing materials, and Nvidia hasn't disclosed what the certification fee will be.
It may be a single up-front fee, a per-board royalty, or some combination of the two. Nvidia has said that not all board makers will be offered the same licensing options and prices. In other words, big guys like Intel might have to pay a lot more for the same certification work, while a big valued OEM partner like Dell may get more generous terms.
Once the board is certified, Nvidia will provide an approval key to the vendor which must be embedded in the system BIOS. The graphics drivers look for this key, and if they find it, they enable SLI in the drivers.
This is good news, overall. AMD/ATI maintains that it will allow Crossfire on X58 boards (and insists there is no licensing or certification fee). With Intel likely to have the fastest desktop processor on the market and chipsets that may optionally support both SLI and Crossfire, that certainly removes some headaches for PC enthusiasts.
Still, it raises some questions. The tech press has often been told that Nvidia will not certify SLI for anything other than their chipsets because there is secret technology within their nForce chips that helps make SLI faster and more robust.
We have been told time and time again that, simply put, SLI wouldn't work well without nForce technology. With SLI on X58 boards that have no nForce chip on them, we can see that it most certainly isn't true. Perhaps certification is necessary to maintain a certain level of quality, but it is most definitely technically possible for SLI to work on boards with no Nvidia technology in them at all.
The broadcast and PW Shortcut features built into nForce chipsets are not entirely necessary now that PCIe Gen 2 has made peer-to-peer writes a standard feature. So why stop at X58 chipsets? Why not support other current motherboards with this certification program?
The X58 motherboards that accompany the Core i7 launch later this year will be, at first, the only supporting platform for Intel's new CPU, and it will have enough PCIe lanes to provide two x16 graphics slots.
Nvidia's hand is sort of forced. There's no real need for an nForce chipset, yet if SLI is not supported on X58, their fastest enthusiast dual (or triple, or quad) graphics solutions won't work on what is sure to be the fastest CPUs around. The company has said it doesn't plan to make chipsets that work with the X58's Quickpath Interconnect (QPI), we assume due to unfavorable licensing terms.
Nvidia's solution? Enable and certify SLI on X58 boards—even with no nForce chip on board. Standard X58 motherboards are eligible for SLI certification. A dual-card SLI setup would have two PCIe x16 lanes, a board with three PCIe slots would have one x16 and two x8 slots, and four PCIe slots would be four x8s.
Of course, Nvidia would still love to sell some motherboard chips, and they'll find a way to do so on X58 motherboards. In three-slot and four-slot enthusiast level boards, Nvidia will sell the nForce 200 chip to board vendors essentially just to use as a PCIe switch—it will connect to the "Tylersburg" south bridge on X58 motherboards and switch one or two of the PCIe x16 lanes to two x16 lanes.
So how does this work? X58 motherboard makers will submit each board model to Nvidia for certification, which will take place in its Santa Clara lab. This is a for-pay certification program, not free—vendors must display the SLI logo on their boxes and marketing materials, and Nvidia hasn't disclosed what the certification fee will be.
It may be a single up-front fee, a per-board royalty, or some combination of the two. Nvidia has said that not all board makers will be offered the same licensing options and prices. In other words, big guys like Intel might have to pay a lot more for the same certification work, while a big valued OEM partner like Dell may get more generous terms.
Once the board is certified, Nvidia will provide an approval key to the vendor which must be embedded in the system BIOS. The graphics drivers look for this key, and if they find it, they enable SLI in the drivers.
This is good news, overall. AMD/ATI maintains that it will allow Crossfire on X58 boards (and insists there is no licensing or certification fee). With Intel likely to have the fastest desktop processor on the market and chipsets that may optionally support both SLI and Crossfire, that certainly removes some headaches for PC enthusiasts.
Still, it raises some questions. The tech press has often been told that Nvidia will not certify SLI for anything other than their chipsets because there is secret technology within their nForce chips that helps make SLI faster and more robust.
We have been told time and time again that, simply put, SLI wouldn't work well without nForce technology. With SLI on X58 boards that have no nForce chip on them, we can see that it most certainly isn't true. Perhaps certification is necessary to maintain a certain level of quality, but it is most definitely technically possible for SLI to work on boards with no Nvidia technology in them at all.
The broadcast and PW Shortcut features built into nForce chipsets are not entirely necessary now that PCIe Gen 2 has made peer-to-peer writes a standard feature. So why stop at X58 chipsets? Why not support other current motherboards with this certification program?
