Question 1

Can this fit in an ATX case, say the phanteks eclipse?

Accepted Answer

I've actually asked Phanteks the same thing. So basically you can't use the "holes" to bring up the power cable  into the MB, also  Sata and Video card power cable...just because this card is to wide and it's overlapping the "grommets" . I've checked the pictures you might be able to get the cables from power supply from bottom case, also from HDD side , but i suspect it will be messy in term of cable management. PS ive orderd the case P400S for the same E-atx specs...

Question 2

Does this board support hdmi connection?

Accepted Answer

The motherboard doesn't have any onboard video connections because the Threadripper platform does not have an integrated GPU.  In other words, you need a separate video card that has an HDMI port (i.e. most of them nowadays.)

Question 3

Does this board support IOMMU?

Accepted Answer

Hello Ryan Carpenter, Thank you for contacting us with your question. We apologize that we are unable to provide you with direct technical assistance; however, we recommend contacting the manufacturer for any compatibility questions. Support Phone: 1-510-739-3777 You may be able to chat with someone who may assist you with your question. Hope this information is helpful. Have an Eggcellent Day! Newegg.com

Question 4

As I looked up its dimension, it is not significantly different from an ATX motherboard and the screw position look the same to me. Any one knows if this mother board can fit into an ATX case?

Accepted Answer

In the the name of page is "Extended ATX AMD Motherboard". It's an E-ATX MB, if you case is built for only ATX motherboard it probably won't fit, or you shouldn't take a chance. I believe E-ATX MB cases need to accommodate another PCI slot. Do a search on "ATX vs E-ATX", the internet will answer.

Question 5

Has anyone tried to network boot one of these? The BIOS manual mentions PXE in passing but doesn't explicitly state support, no mention of iSCSI at all.

Accepted Answer

The motherboard has support for PXE as mentioned under its Manageability features.

Question 6

Will ASUS X399 platform motherboards support the new AMD Threadripper 2nd Gen Ryzen CPUs like the “2900WX, 2950X etc.”? and will the motherboard post with the new CPU out of the box?

Accepted Answer

Enter an ansHello, you mean 2990WX?
Yes, ASUS X399 Platform motherboards are all Ready for AMD Threadripper 2nd Gen Ryzen CPUs support. If your motherboard do not post with the new Threadripper 2nd Gen Ryzen CPU out of the box, you will need to update the BIOS. 
All ASUS X399 Platform motherboards have USB BIOS Flashback support. USB BIOS Flashback is the easiest BIOS flashing method that only require a USB storage and power supply. No CPU , memory or other hardware required.
wer to this question.

Question 7

With all of this tech why is the LAN speed still only 1GB?

Accepted Answer

Because hardly anyone has 10GB-capable networks in the real world?

Question 8

Is there away to break out the u.2 connector to normal sata ports?

Accepted Answer

This board has M.2s not U.2s.

There isn't a way that comes with this product, and would be needed to get 3rd party.

The M.2 ports on this board are somewhat awkward.  The primary requires removing the northbridge heatsink to place your drive, which lays parallel to the mainboard and has a thermal contact pad with said sink.  The secondary is plain ol dangerous to stick your chip drive in as it has only the support of the pins itself and is at risk of snapping off if you move cables or are not careful.  I suggest avoiding using the second port.

Overall though, I'm pretty pleased with this board.

Brand	ASUS
Model	PRIME X399-A

CPU Socket Type	sTR4
CPU Type	Amd ryzen threadripper processor

Number of Memory Slots	8x288pin (DDR4)
Memory Standard	DDR4 3200(O.C)/ 3000(O.C)/ 2800(O.C.)/ 2666/ 2400/ 2133
Maximum Memory Supported	128GB
Channel Supported	Quad Channel

PCI Express 3.0 x16	4 x PCIe 3.0 x16 (single@x16, dual@x16/x16, triple@x16/x16/x8 mode)
PCI Express x4	1 x PCIe 2.0 x4 (max at x4 mode)
PCI Express x1	1 x PCIe 2.0 x1

Serial ATA (SATA)	6 x SATA 6Gb/s
M.2	1 x M.2 Socket 3, with M key, type 2242/2260/2280 storage devices support (SATA & PCIE 3.0 x4 mode) 1 x M.2 Socket 3, with M key, type 2242/2260/2280/22110 storage devices support (SATA & PCIE 3.0 x4 mode) 1 x U.2 port
SATA RAID	0/1/10

ASUS PRIME X399-A sTR4 AMD X399 USB 3.1 Extended ATX AMD Motherboard

Learn more about the ASUS PRIME X399-A

Customer Reviews of the ASUS PRIME X399-A

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Warranty, Returns, And Additional Information

Warranty

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Manufacturer Contact Info

RJ45	1 x RJ45
USB 3.1	1 x USB 3.1 Gen 2 (teal blue) Type-A 8 x USB 3.1 Gen 1 (blue)
USB Type-C	1 x USB 3.1 Gen 2, Type-C
S/PDIF Out	1 x Optical
Audio Ports	5 Ports

Onboard USB	2 x USB 3.1 Gen 1 connector(s) support(s) additional 4 USB 3.1 Gen 1 port(s) 1 x USB 3.1 Gen 2 front panel connector 2 x USB 2.0 connector(s) support(s) additional 4 USB 2.0 port(s)
Other Connectors	1 x 3-pin Cover fan (COV_FAN) connector 1 x Q_Code 2 x RGB Header(s) 1 x M.2_FAN connector 1 x CPU Fan connector(s) 1 x CPU OPT Fan connector(s) 3 x Chassis Fan connector(s) 1 x AIO_PUMP connector 1 x W_PUMP+ connector 1 x Front panel audio connector(s) (AAFP) 1 x System panel(s) 1 x 5-pin EXT_FAN (Extension Fan) connector 1 x Thermal sensor connector(s) 1 x Power-on button(s) 1 x Clear CMOS button(s)

Form Factor	Extended ATX
LED Lighting	RGB
Dimensions (W x L)	12.0" x 10.6"
Power Pin	1 x 24-pin EATX Power connector(s) 1 x 8-pin ATX 12V Power connector(s) 1 x 4-pin ATX 12V Power connector(s)

Onboard Audio
Audio Chipset	Realtek ALC S1220A
Audio Channels	8 Channels

Onboard LAN
LAN Chipset	Intel i211AT
Max LAN Speed	1Gbps

Item#: N82E16813119006