3 - The quest for pins | Multi-GPU support

The quest for pins

Though we all learned to love Socket LGA 775. It just doesnt have enough pins to for that CPU based memory controller, so this is the main reason why Socket LGA1366 is introduced. The socket is called LGA1366, and as you can always decode from the name pretty easily, has 1,366 pins and thus connections to the motherboard.

Read this well if you purchase a Core i7 processor, then you will have to purchase a new mainboard as well as the two sockets are not compatible in any way shape or form. Intels X58 chipset therefore, is the first (and currently only) chipset to support this processor. There is however a horrible rumor that yet another LGA socket will surface later in 2009, socket, LGA 1160 for mainstream processors. We feel this is getting a bit tricky, and hopefully Intel will stick to just one new Socket, Socket 1366.

Since the traditional FSB as we know it is a thing of the past, we have to mention the new QPI, the Quickpath interface, a point-to-point interface. The X58 can have two QPIs and can directly connect to two processors on a multi-socket motherboard. It's a fact that when used with a single Intel Core i7, one QPI is actually unused as you are only using one physical processor. Also good to know, the X58 chipset provides 36 PCI-E 2.0 lanes for single 16-lane, dual 16-lane or quad 8-lane graphics setups. and yes, both ATIs CrossFire multi-graphics and NVIDIA's SLI will work, though SLI support is limited to certain approved and certified by NVIDIA motherboards.

2-way, 3-way and 4-way ATI CrossFireX or NVIDIA SLI configurations

Since we touched the topic NVIDIA SLI support, let's dig right into that one right away a little deeper as this feature definitely made the biggest rumble over the past month whenever the name "X58" surfaced somewhere.

Initially everybody expected that NVIDIA would have its nForce 200 chip to be embedded into the motherboard by board manufacturers, allowing SLI support on X58 motherboards. Over the past year though it became more and more apparent that X58 would get native support, yet under a stringent set of restrictions set by NVIDIA. Mainboard manufacturers can submit their X58 board to NVIDIA and get them certified. Once certified the combo of a BIOS and NVIDIA GeForce Forceware driver will open up SLI support on the consumer side of the experience. So that's native SLI support with a few restrictions. The native SLI support actually doesn't sound too restricted, as motherboards with as few as two PCIe x16 slots and as many as four PCIe x16 slots will be able to support an array of SLI configurations, including a 3-Way SLI and even a fourth graphics card for a PhysX boost. Ironically, the DX58SO mainboard tested in this review is not SLI compatible as it is not SLI certified.

What if a motherboard vendor doesn't want to be restricted and go for multiple x16 v2.0 PCI-Express slots ? Well in theory NVIDIA also gets to sell silicon to board vendors in the form of the nForce 200 chip that acts as a switch between the Tylersburg Southbridge and provides dual PCIe x16 lanes. But since that's more expensive to do from a pure silicon point of view, then theres an extra 5 USD per mainboard to pay for a NVIDIA certification fee, don't expect to see that happening a lot.

Mind you that SLI licensing arrangement will ONLY affect the high and (read expensive) X58 motherboards. No other TBA Intel chipsets will get SLI support anno Q4 2008.

So be careful with this information. The danger here is that not all X58 mainboards are SLI capable. In fact the Intel reference mainboard at hand here today did not support SLI mode. Investigate carefully of you want to opt SLI if your X58 mainboard will support it, most of them will get certified though. We expect most mainboards vendors to get you at least a three PCI Express x16 slots solution to enable 2-way, 3-way and 4-way ATI CrossFireX or NVIDIA SLI configurations. ASUS, EVGA, MSI, Gigabyte, and DFI, have all licensed NVIDIA SLI technology for their new lineup of motherboards.

1,366 pins are needed for Core i7, we didn't count them though.