The Asus M5A99FX PRO R2.0 is an ATX form factor PCI Express 2.0 motherboard.We bought this board as part of  a hardware refresh. The AMD 990FX Chipset is designed to support up to 5200MT/s HyperTransport 3.0 (HT 3.0) interface speed and PCI Express 2.0 x16 graphics. It is optimized with AMD’s latest AM3 and multi-core CPUs to provide excellent system performance and overclocking capabilities.

Even though this board uses the AM3+ socket, we used an AMD Phenom II 965 BE processor with the board which provided a good platform for 64-bit Windows. The M5A99FX PRO R2.0 is positioned as a moderate cost upgrade for AMD users. AM3 processors feature DDR2/DDR3 memory controllers making the board acceptable for a strong upgrade.


  • PCIe x16 (pair)
  • PCIe x4 (pair)
  • PCe x1
  • PCI

The slots are well positioned for most mid-tower chassis when using full length display adapters.

Many motherboards today are full ATX but only have 6 slot positions available. This is due to the larger heat sinks being used with the chipsets. The AMD 990FX is a more demanding crossbar switch and it is loaded hard with a pair of graphics cards. Our old chassis has a bay above the graphics cards which will be ideal for long term use where it is easily accessed when an upgrade is desired.

Unlike the old M2NBP-VM CSM, the PCI Express x16 slot is clear of the SATA headers. We had an available BFG GTX 260 display adapter available that worked fine with this motherboard. Today more and more motherboards are now using the edge type connectors which make it easier to tuck cables under the motherboard tray. There is one SATA port close to the PSU connector to allow a DVD drive to be attached.

The blue slots are the x16 slots targeting graphics cards. The M5A99FX PRO R2.0 supports 4-way SLI and CFX when a pair of dual CPU cards are used. Such configurations need an extreme power supply in addition to a larger chassis.

The black slots are the x4 slots which are available however when loaded with a pair of graphics cards, heat may be a problem for some cards like network controllers or RAID cards.

Today motherboards for dual graphics cards are offering a slot between cards to allow adequate air flow to prevent overheating. Its very advisable to install this board and others like it in a chassis with adequate air flow. The only real need for faster performance is corporate servers where RAID cards with SAS 1200 adapters to large arrays of SSD drives. These $1000 adapters need PCI Express 2.0 or faster slots and the top models even have RAM slots on them for cache memory.

The board also requires a high capacity power supply with the EPS12V connector so that adequate power is available. Additional power may be required if advanced graphics cards are installed.


The 4 memory slots are standard for AMD processors. The M5A99FX PRO R2.0 can support up to 32 GB of DDR3 memory. DDR3 prices have continued to fall: 2048MB are down to $10, 4096MB are under $20 each. In 2015, 8192MB DDR3 sticks were below $50. 16384MB sticks have been noticed at near $150 each but its likely a BIOS update will be needed.

We tested the board with some Micron DDR3-1333 but there was a problem with the timing. We then tried 12288MB DDR3-1600 dual channel and the Phenom II X4 965 was able to select JEDEC DDR3-1600 which is the default speed for the integrated memory controller. The newer FX series processors can support DDR3-1833.


  • USB2 (14 ports, 6 mid-board)
  • USB3 (4 ports, 2 mid-board)
  • Ethernet 1000BASE-T
  • PS/2
  • Audio DTS 7.1

The IO shield is richer than previous motherboards we have used. USB3 is now slowly becoming prevalent however USB2 is still the mainstream for many products. Gigabit Ethernet is still standard however more and more servers are starting to use 10 gigabit Ethernet. Power consumption is still too high for use on a consumer motherboard.

There is no floppy controller on the M5A99FX PRO R2.0 as USB sticks have replaced it completely. The EIDE port is also now gone meaning SATA optical disks are needed in addition to hard disks and SSDs. Even the most recent Blue-ray drives can record to CD and DVD fine.

The blue USB 3.0 mid-board connector is sensitive to bent pins so users should be careful when inserting the front panel cable. Be sure the cable is perpendicular so that it connects properly. Suitable cables are seen on USB 3.0 designed chassis, which have the requisite USB 3.0 motherboard plug. On the IO shield the USB 3.0 ports are colored blue.

HDMI has pushed video card manufacturers to include audio on their products. The audio header is now increasingly a legacy port like the old PS2 ports for the keyboard and mouse.

While the latest video cards now use PCI Express 3, AMD realizes that such speed is unnecessary with graphics cards primarily as they are far from saturating the PCI Express 2 slots. For dual slot rigs the PCI Express 2 performance will remain viable for several generations of video cards even with dual GPU cards.


After overclocking the CPU and adjusting the memory timing the performance of the M5A99FX PRO R2.0 is impressive. Loading 175 GB of audio into iTunes was easily 5x faster compared to the M2N-VM CSM were upgraded from. The scanning for gapless information proceeded so fast it was amazing. Same hard disk, same server, same library.

Our Phenom II 965 BE is easily overclocked to be able to deal with the demands of a dual graphics card situation. The north bridge can be overclocked which can be very helpful when using dual graphics cards.

DDR3 is also less expensive making this board less costly to outfit with 8 GB or more memory. DDR3 prices have come down considerably. The G.SKILL memory we have is now less then a third what it was in Q1-2012.


The M5A99FX comes with a support DVD like all boards, but while the BIOS has the capability of setting the minimum fan speed to 100rpm, the AI Suite II tool can only go down to 600rpm. This is a problem with the low noise 140mm fans we use which operate as low as 400rpm at idle. The means the alerts in the log are overrun with fan speed problems.

The AI suite uses the .NET framework so it has a high startup impact so its not advisable to use it. The BIOS has all of the functionality and the manual is clear enough on how to configure it.

Using C++ and the component oriented model (COM) its possible to access the BIOS and not have such a high system impact.


Windows 10 is being delivered to Windows 7 and 8 users and Asus has been slow to update their OEM software. Windows 10 and DX10 motivate using a pair of dual GPU cards but this board only has a single EPS12V connector which does limit the power capability somewhat. Some more recent motherboard now have dual EPS12V connectors to provide more power. AMD also has higher power processors.