A question about PCIe based M2's

[Teemsan]

I have a motherboard with an onboard surface slot for M2 - the M key variety. The board is a Gigabyte GA H97 D3H

http://www.gigabyte.com/products/product-page.aspx?pid=4962#ov

So I know that my M2 slot runs through the PCIe lane and not SATA III, giving me potentially the higher 10 Gb/s data transfer rate. It would reduce my PCIe x16 slot to x8, but I'm fine with that.

My confusion is regarding the use of both my SATA III drives and M2 at the same time.

I know with my SATA Express connection it uses two of the SATA lanes, making those 2 unavailable while using the SATA Express slot. So is this also the case with M2? Even though it is PCIe based, will it also make those same two SATA slots unavailable? I'm thinking it wouldn't, but I want to check on that before I go with an M2.

 

[i7Baby]

If it was a sata M.2 slot then you'd lose some sata ports - usually 2.

pcie m.2 you lose 2 pcie lanes.

 

[Teemsan]

Thanks i7Baby

pcie m.2 you lose 2 pcie lanes.

leaving me with my 6 SATA III slots still available, correct? Sorry if I'm being redundant, but I want to make absolutely sure before I drop my cash on the M2,
thanks

 

[i7Baby]

Yes. The mobo manual should explain it in detail.

 

[Teemsan]

Yes. The mobo manual should explain it in detail.

I checked the manual. Here's what it shows

That block diagram is confusing to me because I can't tell whether it's saying M2 or "switch" to either one of SATA Express or 2 SATA 6 Gb/s. OR is it saying M2 "or" SATA Express "or" 2 SATA 6 Gb/s - as in a choice of one only of the three.

Then for a written explanation it says:

That info seems conflicting to me. The top says "1 M.2 PCIe connector" and then the part below says "The SATA III 4/5 connectors will become unavailable when an M.2 SSD is installed"

So my confusion was: if the M.2 is listed as PCIe based, then why would it knock out the two SATA III ports that are used by SATA Express???? Makes no sense to me

But if you say that a PCIe based M.2 will still allow full use of the available 6 SATA III's then I'll take that on faith.

 

[The Original Ralph]

similiarly, in the Asus Z97M-Plus board, two sata ports are lost or dis-abled when, when there is any M.2 device installed in the M.2 socket, even if Sata is selected under PCH Storage in Bios (there's a choice there to select "Auto", "SATA" or "M.2" and i was hoping to be able to leave a M.2 SSD installed in the M.2 Socket but be able to isolate it and recapture the two sata ports when i changed the settings in BIOS - no love.

But Asus is equally less than clear in their manual, simply stating the M.2 "shares bandwidth" with sata ports 5 & 6, not that the M.2 disables those two ports. I suspect they describe it that confusingly to keep sales by not making it clear.

 

[i7Baby]

There are sata M.2's and pcie M.2s.

Most M.2 SSDs are currently sata. These lose a couple of sata channels/ports when installed.

The other M.2s are pcie. They lose a couple of pcie lanes when used. The Samsung is about the most common so far - https://www.ramcity.com.au/buy/samsung-xp941-256gb-m.2-pcie-x4-80mm-ssd/MZHPU256HCGL-00000

 

[Teemsan]

There are sata M.2's and pcie M.2s.

Most M.2 SSDs are currently sata. These lose a couple of sata channels/ports when installed.

The other M.2s are pcie. They lose a couple of pcie lanes when used. The Samsung is about the most common so far - https://www.ramcity.com.au/buy/samsung-xp941-256gb-m.2-pcie-x4-80mm-ssd/MZHPU256HCGL-00000

Yes I'm aware of the difference as I mentioned it in my op.

My M.2 is PCIe. you can see from the link in my op to the mobo on the Gigabyte website it's listed as "... an onboard M.2 slot, providing users PCI-Express connectivity for SSD devices."

And form the documentation in the manual (the pic in my post above) under Storage Interface > Chipset it shows "1 x M.2 PCIe connector".

Is there a way to de-select my best answer, as I don't wont others who may read this thread to get false information