M2 pci e 3.0 x4

Hi guys i posted this thread in motherboards, but then realised its probably more appropriate here, so apologies for double post, don't know how to delete my old thread:My motherboard has this feature http://www.asrock.com/news/index.asp?id=2121

I was going to sell my 240gb sandisk extreme pro and buy a Samsung sm951 m.2 ssd. This would give me speeds up to 1700+ on the write and 1500+ on the read as opposed to my current 500+.

My question is, will this steal pci e 3.0 lanes / bandwidth from my gpu?
If so, will it limit gpu performance?
Can this be used as a boot drive? (as i want to remove all my drive cages and other ssds). The big one is 512gb which is enough for me.
I have i7 4790k
Thanks for the help guys!

found my answer, kind of disappointing:
"But there is a problem. On the Intel Z97 platform PCI Express 3.0 is only supported by the microprocessor itself. The CPU has 16 PCI Express 3.0 lanes that can be used to connect a graphics card in PCIe 3.0 x16 mode or reconfigured as 8+8 lanes (to support a dual-GPU configuration) or 8+4+4 lanes (to support a multi-GPU or multi-PCIe devices configuration). As a result, once an SSD in plugged into the Ultra M.2 slot, the bandwidth between central processing unit and graphics processing unit is cut-down by half. Therefore, while the end-user gets additional SSD performance, he/she may lose some GPU performance because of insufficient bandwidth between it and the CPU."

as of:
http://www.kitguru.net/components/m...m-2-ssds-with-ultra-m-2-but-there-is-a-catch/

ok,
ive now found information to suggest that halving the gpu bandwidth doesnt actually make a difference. you wouldnt however be able to sli, as nvidia has an 8 lane minimum restriction on their cards. This plus 2 cards in sli would force 8 x 4 x 4, as opposed to 8 x 8 in sli, or 8 x 8 1 gpu, 1 ultra m.2.

http://www.anandtech.com/show/8045/asrock-z97-extreme6-review-ultra-m2-x4-tested-with-xp941/11

Still undecided though halving gpu bandwidth just feels wrong in a gaming rig lol
it also looks a bit sketchy as to whether it can be used as a boot drive, it all depends on whether asrock update (or have updated) their bios to allow this

Hi

The answer to this question depends on your motherboard and your settings.

For example my motherboard (the MSI X99 SLI Plus) has bios settings that drastically affect the speed of the SSD.

If I set the M2 slot to auto, then I get the full speeds as seen in the image below. I believe this connects the M2 slot straight to the CPU. If however I set the M2 slot from auto to PCIe, then it only gets 10gbit rather than 32 Gbit and I was seeing my speeds halved (I accidentally set it to PCIe originally). My motherboard does allow it as a boot drive, but only for Windows 8.