ECS calls "SDGE" (Scalable Dual Graphic Engines) its motherboards that have two PCI Express x16 slots. These motherboards, however, can have three different architectures to host these two PCI Express x16 slots:

• Using SLI or Crossfire technology. In this case, each slot works at 8x when running under SLI or Crossfire modes.
• Using spare PCI Express x1 lanes to connect the second PCI Express x16 slto. While the first PCI Express x16 slot really runs at 16x speed, the second slot doesn't run at 16x. Its maximum speed will depend on how many lanes were used to connect this slot to the chipset. Besides having two x16 slots, these motherboards cannot run under SLI nor Crossfire modes.
• A new prototype presented by ECS where the two slots really run at 16x speed and where it is possible to have two SLI or two Crossfire video cards together in a system without using a chipset from nVidia or ATI. For example, a motherboard with SDGE technology based on an Intel chipset will allow you to run two SLI VGAs in parallel. In this article we will be discussing this third option, which is still a prototype. So all our references to "SDGE" within this article refer to this prototype and not to the other two architectures.

Basically SDGE motherboard will have two 16x PCI Express slots. These two slots are really x16 and not 8x as it happens on SLI motherboards when you enable SLI mode. To make these slots to work as SLI or Crossfire, however, ECS will need both nVidia and ATI to unlock their drivers to enable SDGE. This will be a very though job, but ECS said “we are working on that”. Let’s wait and see.

click to enlarge
Figure 1: SDGE technology overview.

In our opinion, this concept is very interesting if the user didn’t decide which way to go yet, ATI or nVidia. You can use two SLI cards from nVidia today and, in the future, change to two Crossfire cards from ATI without needing to replace the motherboard. Really interesting – but, as mentioned, unless ECS gets the unlocked drivers from both ATI and nVidia, this concept is useless.

Also, since the second x16 PCI Express slot is only activated thru an add-on card, as we will explain on the next page, the motherboard can be cheaper, which can be a very good solution for users on budget: you can buy a “normal” motherboard now and “upgrade” it to have SLI or Crossfire function later by installing an add-on card.