How does the PCI lanes on an i5 4690k work?

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Kizachu

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Just need an understanding of the 16 CPU lane cap when running 970 SLI's with an SSD etc in the PCI slots on my MSI gaming 5 mobo

So if I buy a 4690k i5 which had a lane cap of 16 meaning I've used up all the lanes with my 8x8x channel 970's. Will I be able to install an SSD into the PCI slots, or a sound card, or even a network card?

Also my Gaming 5 motherboard has an M.2 Sata slot, does that count into the max PCI lanes the 4690k can do?
 
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Leaps-from-Shadows
According to the board's web site, that board supports 16/0/0, 8/8/0, and 8/4/4 for SLI/CF. That means the third PCIe x16 slot is connected to the CPU's PCIe lanes.

If you put anything in the third PCIe x16 slot, it will downgrade the other two slots' lanes to 8/4.

You would be better off using an M.2 SSD, which has its own PCIe 2.0 x2 lanes from the Z97 chipset. You won't get peak SSD performance (you would be stuck at "only" 700-800Mbps), but you also won't cause problems with your SLI setup. The M.2 SSD with those lanes will still be faster than any SATA SSD. Note that SATA5 and SATA6 will be disabled when using the M.2 port.

The manual doesn't mention about anything sharing with the PCIe x1 slots. There probably is some...
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Supernova1138

Supernova1138

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Your CPU has 16 PCI-E lanes that can be split to run two PCI-E x16 slots at x8 speed, that's where you put your video cards. If you want a PCI-E SSD, that will use the chipset PCI-E lanes, which are separate, those use the slots not wired to the CPU's PCI-E controller, refer to the motherboard manual if you don't know which is which.

Either way, you're going to hit a bottleneck on high performance SSDs on your platform while running SLI. The Z97 chipset's PCI-E lanes only run at 2.0 speeds and are limited in quantity, which is why M.2 is limited to 10Gbps. To get the most out of a high performance SSD, you'd need to use the CPU's PCI-E lanes, and that isn't an option while running SLI.
 
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Kizachu

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The motherboard only has 4 x1 slots and that third x16 PCIE 3.0 slot. So you're saying if I were to use a x4 SSD in that third one its still possible with the SLI configuration despite my 16 lane cap because itll use my available chipset lanes instead?
 
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Supernova1138

Supernova1138

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The third PCI-E x16 slot closest to the bottom should be connected to your chipset, with the top two connected to your CPU. You could connect an SSD to the bottom PCI-E x16 slot while you have two graphics cards and it would work. However, your SSD will likely be bottlenecked as the chipset PCI-E lanes aren't fast enough to keep up with the throughput of a high performance PCI-E based SSD.
 
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Leaps-from-Shadows

Leaps-from-Shadows

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Jan 10, 2011
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According to the board's web site, that board supports 16/0/0, 8/8/0, and 8/4/4 for SLI/CF. That means the third PCIe x16 slot is connected to the CPU's PCIe lanes.

If you put anything in the third PCIe x16 slot, it will downgrade the other two slots' lanes to 8/4.

You would be better off using an M.2 SSD, which has its own PCIe 2.0 x2 lanes from the Z97 chipset. You won't get peak SSD performance (you would be stuck at "only" 700-800Mbps), but you also won't cause problems with your SLI setup. The M.2 SSD with those lanes will still be faster than any SATA SSD. Note that SATA5 and SATA6 will be disabled when using the M.2 port.

The manual doesn't mention about anything sharing with the PCIe x1 slots. There probably is some though. Sound and network cards would likely work as long as they are x1 cards.
 
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