M.2 and PCI-e performance

[NirvashOne]

unsure of where to post this, but I read somewhere that if you use an M.2 option, it degrades you PCI-e x16 capabilities.

So if i opted for an M.2 drive would it drop my GPU performance because it uses the pci-e bus? sorry for the stupid question

but i can't find an answer. and i'm building a new rig come tax season and am weighing out my options.

[Oshino Shinobu]

If you've only got 1-2 GPUs, you don't need to worry about it. PCIE x8 won't bottleneck any card. 

[NirvashOne]

ok cool, i really only plan on one gtx 980 so this clarifies things

[MrSuperb]

unsure of where to post this, but I read somewhere that if you use an M.2 option, it degrades you PCI-e x16 capabilities.

Not all M.2 modules actually use PCIe, but rather just mSATA

[NirvashOne]

ok more specifically i plan on using a GB Z97X-UD5H-BK

[harrynowl]

I believe use of the M.2 slot downgrades one of the 3.0 x16 slots to x8 (or 2.0 x16). In multi GPU setups I believe this limits you to x4 x8, or maybe x4 x4.

 

No performance hit at x8

[DirkW]

It always depends on that specific board's design.

 

Whether the PCIe lanes for the M.2 (if it is even really connected via PCIe and not SATA) are taken from the 16 PCIe 3.0 lanes from the CPU or the 8 PCIe lanes from the chipset (e.g. Z87/Z97).