Z97M OC Formula PCIe 3.0 use

You?™re correct that the Samsung SSD SM951 would require an M.2 to PCIe 3.0 adapter for full performance, especially if the motherboard?™s M.2 slot is limited to PCIe 2.0 or fewer lanes. The SM951, whether in AHCI or NVMe mode, needs at least four PCIe 3.0 lanes to perform at its maximum potential.

To address your concern about the PowerColor Radeon R9 285 and the SM951 working simultaneously at their full capacities, you need to check the PCIe lane distribution on your motherboard. Most consumer-grade motherboards have a total of 16 PCIe 3.0 lanes from the CPU, typically allocated as follows:

x16 for a single GPU, or
x8/x8 for dual GPUs, or
x8/x4/x4 for a GPU and two other PCIe devices.
If you?™re running a single GPU, the R9 285 will usually occupy x16 lanes. Adding the SM951 via a PCIe adapter would typically use 4 additional lanes, but this setup depends on the motherboard chipset and how it shares lanes between devices.

Check your motherboard manual for specific lane allocation when multiple PCIe slots are populated. Some boards reroute lanes dynamically based on the devices installed.
GPU Placement: Install the R9 285 in the primary PCIe x16 slot. This ensures the GPU gets the full 16 lanes (or 8 if lanes are shared).
SM951 Placement: Use a secondary PCIe x4 slot for the SM951 (via an adapter). If the board lacks a dedicated x4 slot, an x16 slot that shares lanes with the primary GPU can often operate in x4 mode.
As for additional storage like a SATA 6Gbps SSD/800GB-MU-2.5Inch, SATA drives https://serverorbit.com/solid-state-drives-ssd/sata-6gbps-ssd/800gb-mu-2-5inch operate independently of PCIe lanes and use the motherboard?™s SATA controller. You can connect this SSD to any available SATA port without affecting PCIe bandwidth.

I just read that the read/write speed tests were performed on PCIe 3.0 x4 lanes so x8 is obviously more than enough to maximize the SM951- AHCi or NVMe. YAY! bring on the 3D XPoint

Over clocking the CPU or not does not change the amount of PCIe 3.0 lanes provided by the CPU.

I would not suggest over clocking using the BCLK when using an SM951, they are sensitive to the PCIe buss speed and need it to be very close to 100MHz.

The specs of the different capacity SM951s are somewhat different.


Capacity    Read            Write

128GB       2050MBs     600MBs

256GB       2150MBs     1200MBs

512GB       2150MBs     1500MBs

http://www.storagereview.com/samsung_sm951_pcie_m2_ssd_review

And as an afterthought, I should be getting those 2K read and 1.4K write speeds?(the SM951 will  be OS hard drive.)

Basic reality first, all the PCIe 3.0 lanes on a Z97 board, or any other Intel 9, 8, and 7 series chipset board are provided by the processor.

Next, all the Intel processors that you can use in a Z97 board, or the others mentioned above, provide 16 PCIe 3.0 lanes. The X99 and X79 platforms provide more PCIe 3.0 lanes.

Given the way the PCIe 3.0 lanes are allocated, as soon as you use two cards that use PCIe 3.0 lanes, even if only one lane was used by one of the cards, the video card will get eight PCIe 3.0 lanes.

The same is true in your case. If an M.2 slot uses two or four PCIe 3.0 lanes, the video card will be allocated eight PCIe 3.0 lanes.

The general consensus and reality of video cards using PCIe 3.0 lanes, is that eight lanes will not limit the performance of any current video card. You R9 285 is not a high end card, so will definitely not be limited by being allocated eight PCIe 3.0 lanes.

Your board only has two PCIe 3.0 slots, PCIE1 and PCIE3. Video card should be in PCIE1, the SM951's adapter card in PCIE3.