Asus H81 Series mDTX motherboard


Jun 2, 2013
ASUS Launches H81 Series Motherboards Based on Intel H81 Chipset

PC Perspective Review, August 23, 2013

On June 18, 2014 Asus enabled over-clocking for the Haswell chipset (including H81).

It appears (from Asus manual/documentation) that this mDTX motherboard was released by Asus in the last 6 months (3Q 2014).
This board would be suitable for those HP Pavilion Slimline s3000, s5000 and mDTX computer case owners desiring to upgrade to the latest Haswell processors (Windows 8.1 and future Windows 10 usage).
It would also fit the NCASE M1.

ASUS H81M-R/C/SI (bulk)
Dimensions: 190mm x 170mm

Two Expansion Slots:
PCI Express x16 slot: 1x PCI Express
PCI Express x1 slot: 1x PCI Express

NOTE Placement of PCI Express x 1 slot as First Connector --
So it is not lost when a Graphics card is added. Nice for 3-slot NCASE M1.

Asus H81M-R Manual

While this board is 13mm thinner than the 2007 AMD based mDTX form factor (203mm x 170mm), it does have 2 expansion slots.
It should be a suitable replacement for those Small Form Factor cases (mITX, mDTX, FlexATX).

The rubber support strip at the bottom left of the case should be moved and new contact adhesive (cement) applied to support the edge of the board.
How to Acquire this Board?
It appears it may be sold in the Serbian market ("R" suffix) for ~ $75 USD, since that is where I found it listed.

Contact Asus USA, Component (Motherboard)
Product Support: 1-812-282-2787
Closed in observance of major national holidays.
Monday – Friday, 5:30AM – 11:00PM PST;!contact-us/cw8z

Likely a Bulk motherboard purchase (system integrators, companies like HP) would be required.

IT winkle still has un-branded HP Slimline s3000 cases (ARCHES) for mDTX / mITX motherboards.
He advertises these for ~ $35 on eBay.
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Very cool, I'm curious as to why Asus doesn't sell this board on the aftermarket.

It seems to be perfect for builds that want to use the third expansion slot in the M1, I sincerely hope there will be more mDTX boards like this in the future.
For some Small Form Factor cases (2007-2010), with only 2-slots and designed for the AMD motherboards (203mm x 170mm) of that era,
the solutions are limited outside of the traditional 1-slot mini-ITX (170mm x 170mm).
The HP Pavilion Slimline s3000 case (ARCHES, ARCHES2) is one example.
Power Supply (FlexATX) was at top of case, and potentially top-heavy.
HP revised their design for the s5000 series of Pavilion Slimline cases.

They changed the power supply form factor (TFX) and moved it to the bottom of the s5000 case.
This case can actually fit a microATX (mATX) motherboard, but 2-slots are unavailable (under the TFX power supply).
The case is actually a very good fit for the various 3-slot FlexATX (226mm x 175mm)
"entry-level" Intel motherboards (H81 and B85 of the Intel Haswell/Broadwell series), BUT you still loose one PCI Express x 1 slot.
For those H81-series boards, the Asus H81M-A FlexATX motherboard is an inexpensive replacement.

*** There are Flexible slot extenders that could make that 3rd slot usable (Wireless LAN card), but not an ideal solution.
IDEALLY, for the upcoming Intel Skylake -- the Taiwan/China motherboard manufacturers could offer
a Flex ATX motherboard with the third slot (PCIe x 1) replaced with an M.2 connector.

For ASUS, their 2H 2015 design (H110) is very easy ... Start with the existing H81M-A board design and size.
Look at Intel's last H87 mATX board, DH87RL, Round Lake for some inspiration on back panel ports (video and I/O).
Take positive aspects from their Z97/H97 mini-ITX work.
Display Port and HDMI will be preferred back panel video connectors.

1. Replace the 3rd expansion slot with a M.2 capable slot (PCIe MiniCard/mSATA as a fall back).
2. Keep the existing (2) internal USB 2.0 headers (2x5) for existing Front I/O and Media Cards on legacy cases (total of 4 ports).
3. Add a USB 3.0 header (2 ports) for newer cases that have those ports on case front panel.
4. Have ability to easily add a Wi-Fi card (M.2 or PCIe Mini Card).
That would allow the M.2 slot, underneath the TFX power supply to supply a SSD or Wireless Card.
While I understand the issue of placing the M.2 slot on foil side of Asus Z97/H97 motherboards (mini-ITX),
avoid that design with FlexATX boards.
Work with SSD suppliers (newer chipsets) to reduce reported thermal issues with SSD (M.2 form factor).
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Well mDTX is more of an upgrade to mITX, not a smaller version of mATX. On those dimensions, 4 memory slots are near impossible to implement.
I see that Asus has recenly added a new H81M-P, motherboard, another 2-slot mDTX style !
This appears to be available in North America.

Asus H81M-P Manual (English)

uATX Form Factor : 7.5 inch x 7.0 inch ( 19 cm x 17.7 cm )
2 Expansion Slots: 1 x PCIe 2.0 x16; 1 x PCIe 2.0 x1

1 x PS/2 keyboard (purple)
1 x PS/2 mouse (green)
1 x DVI-D
1 x D-Sub
1 x LAN (RJ45) port(s)
2 x USB 3.0 (blue)
2 x USB 2.0
3 x Audio jack(s)

1 x USB 3.0 connector(s) support(s) additional 2 USB 3.0 port(s)
2 x USB 2.0 connector(s) support(s) additional 4 USB 2.0 port(s)
1 x LPT header
1 x COM port(s) connector(s)
2 x SATA 6Gb/s connector(s)
2 x SATA 3Gb/s connector(s)
1 x CPU Fan connector(s) (1 x 4 -pin)
1 x Chassis Fan connector(s) (1 x 4 -pin)
1 x 24-pin EATX Power connector(s)
1 x 4-pin ATX 12V Power connector(s)
1 x Front panel connector(s)
1 x Front panel audio connector(s) (AAFP)
1 x Internal speaker connector(s)
1 x Chassis Intrusion connector(s)
1 x 14-1 pin TPM connector
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