That's a P45 chipset, and only has 16 PCI-E lanes.
See: http://ark.intel.com/products/35133/Intel-82P45-Memory-Controller-Hub
One card is probably taking 8 lanes, the other two 4 lanes each, leaving none free.
Topic: ASUS P5Q deluxe - cannot get more then 3 GPUs to run (Read 3049 times)
One of my scrypt mining rigs has an ASUS P5Q deluxe mobo.
This board has 2 PCI-E X1 and 3 PCI-E x16 slots.
I have a GPU plugged directly into the primary x16 slot and two other cards on risers plugged into the x1 slots.
I'd like to plug in two more cards but, if I plug a riser into either of the other x16 slots, then the card on that riser is not seen and the card on one of the x1 slots is no longer seen. I have tried an assortment of different cards in the slots and this is always the case.
Are there any special tricks that I need in order to get more than three cards running on this mobo?
TIA
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