What type of CPU would I need to 3 way-SLI 980 ti's?

[Jake458]

would an i7 4790k be enough?

 

[rowdymoody]

Yes.

 

[ONKI]

4790k will be enough but best results be on an extreme series processor

 

[Jake458]

whats an extreme series processor?

 

[ONKI]

http://www.futuremark.com/hardware/cpu

 

[Joseph DeGarmo]

For 3-way SLI, an X99 motherboard and Haswell-E CPU is highly recommended. Running 3-way SLI on a Z97 motherboard requires three available PCI-E x16 slots and a PLX chip. The i7-4790k only supports 16 PCI-E lanes and can only run the cards in x8/x8 mode on a normal motherboard. Getting a motherboard with a PLX chip, which simulates 32 PCI-E lanes, such as an ASRock Z97 Extreme 9, will cause high latency, which can be frustrating. For 3-way SLI, an i7-5820k supports 28 PCI-E lanes and will let the cards run in x8/x8/x8 mode, which is acceptable. An i7-5930k supports 40 PCI-E lanes and will make the cards run in x16/x16/x8 mode, which is even better. So in your case, an i7-5820k will be enough.

 

[rhysiam]

Just for the record, you can't actually run SLI on a card in anything less than a x8 PCIe slot. Nvidia disables it. Ironically you can run SLI on x8 x8 PCIe 2.0 slots, but you cannot run on a PCIe x4 slot... SLI will be greyed out in that situation (even though they're basically the same bandwidth). Crossfire will work in a x4 slot.

Not that it really matters because it's not a great idea anyway... but it's worth noting for others. Even with lower tier cards where a x4 PCIe 3.0 slot would probably provide plenty of bandwidth, you can't do it.