ASUS P9X79 WS X79 LGA 2011 Sandy Bridge-E Workstation Motherboard Review


Today we are looking at the ASUS P9X79 WS which is a workstation motherboard built around Intel’s X79 chipset and the LGA 2011 Sandy Bridge-E processors. Unlike the previously reviewed ASUS P9X79, this is a higher-end part, with a lot more functionality built-in. Unlike the base model, the ASUS P9X79 WS contains workstation-centric features such as additional PCIe slots and dual Intel network controllers that provide a lot of extra versatility. All of this versatility does mandate that the ASUS P9X79 WS is a big board measuring up to SSI CEB size specs. In this review, we will look at some of the features that make the board unique.

Test Configuration

One thing I wanted to do with all LGA 2011 reviews was to test stability using the maximum number of DIMMs. Frankly, one of the most compelling features of the LGA 2011 and its Intel Xeon and Intel Core i7 CPUs, single socket desktop platform is the ability to utilize up to eight DIMMs, which is something a user would have previously needed a dual socket system or a single socket AMD G34 platform to do.

  1. CPU(s): Intel Core i7-3930K and Intel Xeon E5 8-core 16 thread CPU
  2. Motherboard: ASUS P9X79 WS
  3. Memory: 32GB (8x 4GB) G.Skill Ripjaws X DDR3 1600
  4. Drives: Corsair Force3 120GBOCZ Vertex 3 120GB
  5. Chassis: Norco RPC-4220
  6. Power Supply: Corsair AX850 850w 80 Plus Gold
I will mention that I used a lot of different cards with this board including three 10GbE adapters, a four port GbE adapter, a six port GbE adapter, two LSI SAS controllers and a Mellanox dual port Infiniband adapter. All of the cards worked without issue which was nice. I am keeping this test to 32GB of RAM solely because I know a lot of my readers will use a similar setup with VMware ESXi 5.0 free edition which has a 32GB RAM limitation at present.


The ASUS P9X79 WS motherboard is a SSI CEB size motherboard which is not uncommon in the server and workstation market, but is larger than the standard ATX, and smaller, form factors many consumers are accustomed to with Intel Core i7 systems. SSI CEB motherboards are 12″ x 10.5″ whereas a standard ATX motherboard is 12″ x 9.6″. That 0.9″ does not seem significant, but we will see a reason why it matters later. One note is that as far as mounting holes go, I was able to use standard ATX mounting points. This means if one has an ATX chassis that has enough depth, everything *should* work fine. One also has to remember that for single-socket solutions, the Sandy Bridge-EP LGA 2011 platform uses significantly more room than a LGA 1155 (Ivy Bridge/ Sandy Bridge) board because the expansion possibilities are much greater than on the lower-end platforms.
ASUS P9X79 WS Overview
ASUS P9X79 WS Overview
The LGA 2011 socket is physically larger and eight DDR3 DIMM slots take up a lot of space. There is a decent amount of room around the socket. Very large heatsinks on the Intel Xeon or Intel Core i7 CPU and memory may interfere with each other.
I have to note that the 8-pin CPU power connector is located at the top of the board near the rear I/O panel. This can be a very busy area as there is a motherboard mounting point in that corner, the rear I/O shield and also many watercooling loops have hoses running in that area. It can be a bit awkward to have the 8-pin power connector in that spot in tight cases or cases that become tight where large radiators and/ or fans are attached above the board. Not a big deal, but it is probably my biggest gripe thus far.
ASUS P9X79 WS 8-pin Power Connector
ASUS P9X79 WS 8-pin Power Connector
One can see that unlike the standard ASUS P9X79 board, the WS version does have additional heat pipe cooling for the VRMs and other components. For those using the Intel Core i7-3930K C2 stepping or Intel Xeon CPU, one can make the fastest single CPU ESXi 5.0 machine with VT-d by using a board like the ASUS P9X79 WS.
ASUS P9X79 WS CPU Socket
ASUS P9X79 WS CPU Socket
Aside from the eight DIMM slots, the ASUS P9X79 WS has six PCIe x16 (four split 32 PCIe lanes through the use of PCIe switches, and two x4 electrical) slots which help take advantage of the massive PCIe bandwidth that the LGA 2011 platform offers. One exciting thing is that the LGA 2011 platforms will support PCIe 3.0 when the specs become final, so these slots will double bandwidth potential over PCIe 2.0 over time. Those x4 slots will effectively have the same throughput as today’s PCIe 2.0 x8 slots. ASUS supports both AMD Quad Crossfire X and NVIDIA Tri-SLI on this board, and after testing a ton of server cards in this board, it does look like one can get a lot of flexibility from the board’s expansion slots.
ASUS P9X79 WS PCIe 3.0 Slots
ASUS P9X79 WS PCIe 3.0 Slots
In a configuration similar to the ASUS consumer LGA 1155 line (for Sandy Bridge and Ivy Bridge CPUs), the P9X79 WS has eight SATA ports in the lower right portion of the board. These ports all run parallel to the PCB which makes cable management easier, especially with front-of-chassis drive bays. The light blue ports are SATA II 3.0gbps and the white ports are SATA III 6.0gbps, all six of which hang off of the Intel PCH. The two dark blue ports are SATA III 6.0gbps ports that hang off of a Marvell 9128 PCIe controller. These two Marvell ports allow for a SSD caching feature, similar to what Intel offers, but ASUS has wrapped it in a more user-friendly design. One can use the SSD caching feature to hang a SSD and a traditional spindle disk off of the ports and software will intelligently put commonly used files on the SSD for a speed boost. I am a big fan of this type of software both on desktops and in servers so it is good to see.
The huge PCH heatsink really does show the fact that Intel was originally expecting the X79 chipset to support eight SAS 2 6.0gbps ports and a RAID engine, but that support was pulled just before launch. Some vendors are enabling this functionality, but I would be wary as Intel obviously pulled this feature for a reason. One can see on the bottom edge of the board below that ASUS provides an internal USB header, which is great for USB key authenticated software and running things like VMware ESXi/ Linux off of a USB drive.
As was mentioned earlier the SSI CEB motherboard size is slightly larger than a standard ATX board (0.90″ wider.) I had installed this board originally in the 4U Norco RPC-4220 chassis with no issue. When I moved to the much smaller mid-tower Corsair Carbide 500R I found that the board fit, but the supplied ASUS SATA cables were too large to fit anywhere other than the top SATA ports (see the below picture.) I did manage to figure this out shortly thereafter but it was a bit frustrating. Simple word of warning, make sure the chassis you chose can fit SSI CEB motherboards if you purchase a ASUS P9X79 WS. I did not check the Carbide 500R’s specs (only mATX and ATX compatibility are listed) and paid for it with a few minutes of troubleshooting.
SATA Clearence ASUS P9X79 WS and Corsair Carbide 500R
SATA Clearence ASUS P9X79 WS and Corsair Carbide 500R
The rear I/O panel has dual PS/2 ports for legacy backward compatibility. As a forward looking feature the P9X79 WS has four USB 3.0 ports (two on the rear panel and front panel USB 3.0 connector for the other two alongside its  eight USB 2.0 ports (as part of the thirteen total the board supports.) One of the USB 2.0 ports is used for a feature called BIOS flashback that one can use when one needs to re-flash the BIOS. Specifically the BIOS flashback feature uses standby PSU power to perform the flash, without other components installed. I found this to be very useful the one time I tried it for the original ASUS P9X79 review.
ASUS has put a big emphasis on using Intel gigabit NICs on their consumer and Intel Xeon boards, and the P9X79 WS has two Intel Gigabit NICs one Intel 82579V controller and one Intel 82574L. I strongly prefer (as do many others) Intel to Realtek NICs so this is a big plus, especially with the Intel 82574L being one of, if not the most well supported gigabit NIC around. 7.1 audio is provided by the Realtek ALC898 and two features ASUS is pushing throughout its X79 line, dts UltraPC II and dts connect. Both of these features from DTS Inc. more or less serve to take an audio source and up mix it to 7.1 or take a 7.1 source and mix it for headphones, stereo speakers and the like. The ASUS P9X79 WS also includes S/PDIF optical out port, the importance of which is probably diminishing slightly due to the prevalence of HDMI interfaces.
ASUS P9X79 WS Rear IO Ports
ASUS P9X79 WS Rear IO Ports

Aside from the PS/2 ports, ASUS also includes rear I/O and an internal header for IEEE 1394a Firewire ports which some users will need others will not. Personally, I would not prioritize Firewire over other features these days. One big point for those users looking at that rear panel and thinking something is missing, there are no eSATA ports available on the rear panel. ASUS does include a PCI bracket if someone does need connectivity in the rear of the chassis. I would have liked to see ASUS drop the Firewire ports in favor of adding Bluetooth and/ or WiFi.


Probably the most interesting piece of software is the UEFI interface that ASUS provides. For those accustomed to standard BIOS that have been used for decades, the ability to use a mouse is welcome. I did find though that using a mouse was almost necessary as navigating by keyboard was not as slick as old AMI, Phoenix, and Award BIOS implementations. The UEFI interface provides a simple mode (called EZ mode) that shows things like boot order, and lets a user change profiles between a power saving profile, balanced profile, and performance profile.


Beyond the UEFI interface, ASUS provides a suite of software including AISuite II  and ASUS Fan Xpert+. Plenty of details can be found on ASUS’s site, but the highlights from this software are the abilities to:

  • Monitor system information from fan speeds, temperatures, voltages, clock speeds and etc. and set alerts.
  • Overclock the CPU if desired either manually or using a CPU auto tuning feature. The base clock can be increased too by a small amount as 100MHz to 103MHz base clocks are generally obtainable from a 100MHz base. One can also change the CPU multipliers.
  • Set the EPU power saving profiles and features. The EPU is a feature of ASUS motherboards meant to intelligently reduce power consumption.
  • Set and test fan speeds using Fan Xpert+. This can be useful if one wants to set thresholds and test them for quieter idle fan speeds ramping up as the workload increases.

Overall I found these utilities to be fairly useful and given the minimum of 8 threads one has with the LGA 2011 platform, performance is not an issue with these having fairly low CPU requirements. One should note that best practice will be to install each utility and driver individually as ASUS does include a small amount of bloatware with their automated installation.


Breaking this board down, I would have to recommend the ASUS P9X79 WS  over the standard P9X79 if one wanted to build a big platform. VMware workstation and Hyper-V virtualization solutions are going to be an increasingly interesting option for developers as one can fill this board up with 64GB of RAM and have more virtual machine RAM available than with ESXi 5.0 which is limited to 32GB total. I would urge ASUS to look at trying to fit the board in an ATX form factor and to come up with a plan to phase-out the Firewire functionality in favor of Bluetooth and possibly WiFi. The number of users with mobile devices that are both Bluetooth and WiFi enabled probably outnumber those that have Firewire devices several-fold at this point. With that being said, having so many PCIe x16 physical slots is great and the board has lots of expandability options and nice software features. I do think the board is expensive, but a platform like this costs three times as much for a common CPU and memory configuration versus a LGA 1155 board, so a motherboard that is 50% more does not seem too onerous. Buyers know that it is a lower volume platform, and more complex as one can easily see eight DIMM slots. At sub-$400 I think the board is still priced fairly.

ASUS P9X79 WS Summary
ASUS P9X79 WS Summary


  1. going to order one of these this week. raid card compatibility is key. might try vmware workstation with 64gb as thats a great idea patrick

  2. Please do more of these reviews. Everyone else does gamer reviews. Some people just want a stable and expandable system.

  3. Ordered one this morning. Can’t wait for it to get here. i7-3930k or wait for a Xeon? What cooler to use? Can I use 8x8Gig unbuffered ecc?

  4. Great looking board. Black & white with some blue sticks out. ASUS should make a 64gb memory kit in the same colors for their boards.

  5. You mentioned the Carbide 500R, did work in the end? You have a picture but didn’t mention in the test configuration.

  6. Can you review of motherboards that can used for gpu computing. preferably more than 4 GPUs cause gaming boards already allow 4GPUs. There are boards with 7 or 8 PCIe slots but they don’t allow all of them to be used with GPUs they become unstable.

    A review of such boards and testing them how many max GPUs do they allow would be great.

  7. How does 64gb ram work on asus p9x79 ws board?

    I am trying to figure out, searching online but couldn’t find any answers.
    Basically, do you really have to have all 64gb (8x8gb) sticks from the same set to work?
    If I get 2 sets of 32gb (4x8gb), will it work?
    Now second question will be, probalby with 1 set of 64gb, I am able to use XMP?
    With 2 sets I can’t? But they are exactly same memory, just 2 different sets at 32gb per set
    Please help me clear the confusions

  8. Generally it is OK not to use a 8x8GB kit and instead use 2x 32GB (2x4x8GB) kits or 8 16GB (2x 8GB) kits. If you can, match the kits. A lot of memory manufacturers sell the same sticks just in different quantities to meet different capacity needs.

  9. Did you actually try this board with a Xeon CPU? I am considering this combo for an audio workstation.
    What type/brand of SATA cables worked in the bottom ports on the the Corsair case.

  10. I really like the features of this motherboard, including the Firewire and serial port internal headers, both of which I’ll use for compatibility with other devices.

    Having on-board wireless capabilities would have been a potential security risk.

    It might not be for everyone, but for me this is the closed to an ideal motherboard that I’ve been able to find for the current system build I’m looking at making.

  11. Hello Patrick. as I’m trying to discover a 64GB 8 Dimm kit or 32GB for that matter that is 8 piece and fast & stable for P9X79/i7-3960X based system…

    As I can’t seem to find answers that share a common ground…

    As you suggest Generally it is OK not to use a 8x8GB instead use 2x4x8GB

    is contradicting The Corsair point of view… Perhaps that’s because they don’t have 8x set but isn’t it true that less Dimm slots filled is less strain on the CPU and the memory controller?


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