EVGA X99 Classified Motherboard Review

The Hardware Asylum Multi-GPU index is a portable set of data we can use to determine the multi-gpu potential of any motherboard.  A higher index number indicates a favorable condition for multiple graphics cards while a lower number indicates a hindrance in one of our leading indicators.  Since the Index is not dependent on system architecture it can be applied to any motherboard regardless of processor or chipset generations.

Index: 5.5
Optimized: 2x
Max Support: 5x

Index: 4.25
Optimized: 3x
Max Supported: 4x

NVidia SLI
AMD Crossfire

As indicated by the PCI Express layout chart there are a total of five 16x PCI Express slots on this motherboard with all five using bandwidth earmarked for video cards.  The configuration is rather unique because you are given a choice of bandwidth allocations depending on your system configuration.

The five 16x slots all use bandwidth directly from the CPU.  This configuration changes if you are using a 28-Lane processor where slot #4 is disabled completely and slot #7 loses some bandwidth.  I found the overall layout to be a little strange.  Slot #1 is the typical primary graphics card slot and will use 16x lanes of bandwidth provided you don’t populate slot #3.  Slot #5 (which is rather far away) is the second primary slot and shares bandwidth with the upstairs neighbor (slot #4).  The strangeness starts when running 3-way and 4-way SLI where you have 8x slots all the way down except for slot #5 which remains at 16x.

For best video performance you will want to populate slots #1 and #5 with video cards.  For proper quad card configurations you'll populate slots #1, #3, #5 and #7.

While researching the Multi GPU Index I successfully loaded windows with five video cards installed.  These included five HD 4850's which might be rather dated in the GPU world but remains as the only 4-way capable GPU with a single slot cooler.  While I consider the X99 Classified to be optimized for dual card configurations you do have the ability to construct a five card super computer provided you use single slot coolers.