PCI Express and MB Question

byronape

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Nov 13, 2012
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Ok, so I've been scanning the forum for a while and have about given up looking for the exact answer I'm looking for.

So I'm an IT pro looking to get back into PC gaming. Since I've only been engrossed in the business end of computers for some time, I'm a bit out of touch with the modern graphics parlance.

I'm looking at MBs to go with either a Ivy Bridge or Haswell i5 k line (for overclocking). I'm considering the Ivy Bridge because I can get it for a good price from a "business" source... but that's only barely relevant to my question.

I'm seeing reasonably priced boards that offer 1 x16 slot and another x16 slot but with text saying that it will run at x8 if there are two cards installed. I'm assuming that it cuts both cards down to x8 since it will be sharing the bandwidth on the MB, or that the second card just runs at half speed. For someone that doesn't demand the highest frame rates for the most cutting edge games, is there any real value in getting a MB with two x16 slots that both run at full speed when both slots are used? Is that even an option? I wasn't planning on getting a GPU that costs more than $200 since I'm working within a budget, if that matters.

Hope this isn't coming off as a hopelessly noob question, but I couldn't find exactly what I was looking for. If someone has a good, technical explanation and wants to take a few minutes to look really smart, I'd love to see what you have to say.

Thanks!
 
Solution
If you're only getting one $200 card then the rest is redundant. Most mobos accomodate at least one card at pciex16. Some will accomodate 2 cards at that. X79 provides enough lanes to do 2 x 16. But for lga1150 you only get 1x16 or 2x8 because the cpus can only accomodate less pcie lanes. X79 can do 2x16 plus 2x8 if needed.
pcie 3.0 lanes provide a fast enough data rate that all todays graphics cards will never use that much data. In fact x8 is more than OK for them all.
If you're only getting one $200 card then the rest is redundant. Most mobos accomodate at least one card at pciex16. Some will accomodate 2 cards at that. X79 provides enough lanes to do 2 x 16. But for lga1150 you only get 1x16 or 2x8 because the cpus can only accomodate less pcie lanes. X79 can do 2x16 plus 2x8 if needed.
pcie 3.0 lanes provide a fast enough data rate that all todays graphics cards will never use that much data. In fact x8 is more than OK for them all.
 
Solution
well unless the board has a plx chip to give the 2 full x16 and then witch I think your down two socket 2011 but if you stick with a z77/z87 board your stuck with split pci-e slots [1x16/2-8x8] I'm not 100% if there is a socket 1150/1155 that has a plx chip on it.

I'm running a x87 board and a i5 4670 and I don't see were its hurting me as of today.. so good luck