TPU writes the most affordable version of Intel's Haswell-E, the Core i7-5820K, will have a narrower PCIe lane than the more expensive Core i7-5930K and Core i7-4960X variants. The latter models will offer 40 PCIe lanes whereas the 5820K will have just 28 lanes.
This means there won't be much difference for multi-GPU configurations between the Core i7-5820K and the LGA1150 Haswell platforms.
On motherboards with, say, three PCI-Express 3.0 x16 slots, the i7-5930K and i7-5960X will let you run two slots at full x16 bandwidth, and a third slot at x8. On systems with the i7-5820K, the second slot won't go beyond x8, and the third one will cap out at x4. On boards with four slots, one of them will run out of bandwidth. The trade-off for this narrower PCI-Express interface is the fact that you're getting six "Haswell" cores, twelve logical CPUs enabled with HyperThreading, about 12 MB of L3 cache, and a quad-channel DDR4 memory interface, at a price-point not too far off from the Core i7-4790K.