X99 OC Fomula & 3.1 OC Formula

On the topic of nVME I've heard of Samsung 850 / 950 or similar nvme drives but they seem to be PCI-e GEN 3 @ X4 but in the case of the M.2_1 @ x 2 GEN 2 PCI-e

fraz wrote: Hi, Yes that is the one M.2_1 - This means the OC Formula has the edge over the 3.1 in this particular respect if it is hard wired.   I'm not complaining just getting to the bottom of things.  In this slot 10 Gb/s is OK and also 10 Gb/s for the USB-C on the back panel. Regarding the 3.1 card which is 2 x USB 3.1 - This would connect into a PCI-e GEN 3 slot, would this be OK in any of the PCI-e slots? - GEN 3 slots go through the CPU PCI-e lanes don't they? The OC Formula / 3.1 also has 32 Gb/s M.2 so there is plenty of tech to use, enough for me anyway, I just ask all these questions to further the understanding. M.2_1 does use / disable 2 x SATA 3 ports. It's great having these boards even though they are a little older now. As long as there is enough tech to get a job done and use the computer then it will work really well, whether now or in years to come. Does 3.1 card go through CPU PCI-e lanes? - I thought it may due to it being GEN 3

On the X99 platform, the PCIe lanes provided by the CPU are PCIe 3.0/Gen3.

The USB 3.1 card may be connected to any PCIe slot connected to the CPU, or the single PCIe slot connected to the chipset. The USB 3.1 card instructions recommend using a PCIe slot connected to the CPU's PCIe 3.0 lanes, specifically the PCIE3 slot, since it is an x4 slot electrically.

But here is where the USB 3.1 card's specs matter. While the card uses an x4 physical interface, the electrical connection to the slot is x2. So it is only capable of connecting to two PCIe lanes, of any generation. That is a limitation of the ASMedia ASM1142 chip used on this USB 3.1 card. So connecting the card to a PCIe 3.0 slot, with two lanes being used, at 8Gb/s per lane, is 16Gb/s theoretical maximum data throughput. The card is rated for data rates up to 10Gb/s, due to the early version of the ASMedia USB chip used in this card, and the USB 3.1 spec at the time this card was designed.

I'm not sure what you mean by the USB 3.1 card being Gen3, but if you mean something like the latest USB 3.1 Gen3 spec, this card does not match the latest USB 3.1 spec. I believe you were thinking if the card used the PCIe 3.0 lanes from the CPU, that it would be capable of 20Gb/s. But for the reasons I described above, it isn't, sorry to say.

fraz wrote: OK no answers so I'll ask one question at a time -  - Please answer On ASRock X99 OC Formula 3.1 there is a PCI-e GEN 2 M.2 @ 10 Gb/s over x2 PCI-e chipset lanes. Is it possible to allocate this M.2 with x4 PCI-e lanes so it will perform @ 20 Gb/s? On the X99 OC Formula [non 3.1] the same M.2 is @ x4 straight out of the box. Please not I am not referring to the M.2 PCI-e GEN 3

No it is NOT possible. The M2_1 slot, like all M.2 slots, is hardwired to its interface. So this M.2 slot will always be PCIe 2.0 x2.

Guess what the other two PCIe 2.0 lanes in the X99 OC Formula/3.1 are used for? Yes, allocated for use by the USB 3.1 card, or other device in the PCIe 2.0 slot. Only a limited amount of resources available, even on X99.

If you want to use an M.2 SSD with a better interface, use an M.2 to PCIe slot adapter card in one of the PCIe 3.0 slots. The CPU you use may limit this, if it only has 28 PCIe 3.0 lanes.

Regarding the USB 3.1 card used with the X99 OC Formula/3.1, it was designed at the time that USB 3.1 meant 10Gb/s. Yes, the USB organization has changed what USB 3.1 means since then, but that does NOT mean the USB 3.1 card supplied with this board has changed too. If one of the "USB 3.1" ports could operate at 20Gb/s, then the specs would say so. Marketing would never miss a chance to highlight such a feature if it existed.

Hi,