Motherboard Asus X99-M WS review – Worth the Wait?

jeshikat

Jessica. Wayward SFF.n Founder
Original poster
Silver Supporter
Feb 22, 2015
4,969
4,780
That should work. The top two slots will run in x16 / x16, then the bottom slot will be x8. At least with a 40-lane CPU.

The PCIe slot configuration does not have any effect on the SATA ports on this board, so the second drive will run at regular speed.
 

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King of Cable Management
Sep 26, 2015
775
759
Least appealing Asus WS board ever? Why doesn't this have 4 x16 slots?

4 x16 slots does absolutely nothing but take up real estate on the board, which is already getting a bit cramped on a μATX board. Electrically, you are going to have 40 PCI-e lanes and when you try to make lanes split between two connectors, you will need quick switches, adding complexity and degrading signal integrity a little. A set-up like the X99-M WS should conceivably benchmark (potential cold bug issues aside) better than the Rampage V board for up to three GPUs.
 

nox

Average Stuffer
Feb 10, 2017
81
52
hmmm one x2 m.2 slot isn't good. Even seeing two x4 m.2 slots on some mini itx boards now...
 

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King of Cable Management
Sep 26, 2015
775
759
Yeah, that's the aged X99 platform for you. X299 should be better with one or more M.2 slots connected directly to the CPU rather than being bottlenecked at the chipset.
 

Singular

Chassis Packer
Jan 25, 2016
15
13
First, the x99 platform its not for the mainstream, if you need more than 4 cores x299 its useless, there are atx and eatx x99 motherboards with more than one m.2 x4 slot, x99 its not aged its just not mainstream, for example a x99 deluxe II with a 40 lanes cpu, can give you enough room for 3 gpu and a m.2 slot full speed configuration with type c usb and wifi, the full package, even thunderbolt connections.
 

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King of Cable Management
Sep 26, 2015
775
759
If you share enough bandwidth, yes you can support a lot of devices. Keep in mind that all of the quick switches you would need add a lot of design complexity. There is always a compromise, and you need to take from something to give to another as those 40 lanes are only divisible in groups of 4-lanes (each group of 4-lanes has it's own PCI-e controller; they can be combined, but cannot be split). Also, in X99, you cannot do a hardware RAID of storage devices connected to the processor; there is no logic in the CPU for that and can only be done in software. The ideal X99 μATX board would be two x16 PCI-e 3.0 slots for GPUs and two x4 PCI-e 3.0 M.2 slots...no need for quick switches and a straight forward high performance design. But also keep in mind that enterprise users have other needs like high performance networking (take a look at this build to get an idea).

X299 is the successor to X99 and will support 6- to 10+cores Skylake-X processors (as well as the 4-core Kaby Lake-X). You are thinking Z270 with the limit to 4 cores. X299 will basically have the same amount of I/O from the chipset as Z270 does: 30 HSIO (flexible between PCI-e lanes, SATA, USB, Ethernet) and up to three Intel RST devices. Skylake-X will also have 44 PCI-e lanes directly from the processor, specifically to address high speed storage needs.

Also, the only X99 board that is ITX is the ASRock X99E-ITX/ac that only has one M.2 slot on it (it is x4 PCI-e 3.0, as they aren't using those lanes for additional PCI-e slots).