Exclusive: First ASUS P9A-I/C2550/SAS/4L Review

ASUS P9A-I-C2550-SAS-4L-Overview
ASUS P9A-I-C2550-SAS-4L-Overview

When we first heard of the ASUS P9A-I/C2550/SAS/4L we were admittedly excited. Here is a motherboard with a low power (14w) TDP Intel Atom C2550, quad gigabit Ethernet and onboard connectivity for up to 18 drives, all in a mITX package. Since we first published our preview article of the three ASUS Avoton motherboards weeks ago, we have been getting countless e-mails regarding the question of when they would arrive. Five days before my wedding, I got a note from ASUS that the ASUS P9A-I/C2550/SAS/4L hit North American shores and within 48 hours I was able to get one.

Test Configuration

We used what is likely to be a common configuration for these platforms. Essentially, with the network and storage configurations afforded to the motherboard, this is being positioned as a cold storage platform.

  • Motherboard/ Processor: ASUS P9A-I/C2550/SAS/4L with embedded Intel Atom C2550
  • RAM: 2x 2GB Kingston ECC 1600MHz UDIMMs, 2x 4GB SK.Hynix ECC 1600MHz UDIMMs, 2x 8GB Micron ECC 1600MHz UDIMMs
  • Storage: 16x Western Digital Red 4TB drives, 2x Seagate 600 Pro 256GB SSDs
  • Power Supply: PicoPSU 150XT, Seasonic 650w (with hard drives)
  • OS: Ubuntu 14.04 LTS, Windows Server 2012 R2, CentOS 6.5

We did not have a chance to run our full PCIe card suite with this platform due to time constraints but will do so later in July 2014.

The ASUS P9A-I/C2550/SAS/4L

Looking at the ASUS P9A-I/C2550/SAS/4L it is clear that the platform is very tight on space. The mini-ITX form factor allows for a 6.7″ x 6.7″ motherboard. The ASUS P9A-I platform has space for two full-length DDR3 DIMM slots. There are a rare few 16GB ECC UDIMM modules available so practically this is allows for 16GB of 1600MHz ECC memory in 2x 8GB configurations.

ASUS P9A-I-C2550-SAS-4L-Overview
ASUS P9A-I/C2550/SAS/4L Overview

Before we get to all of the onboard components, the ASUS P9A-I platform also has a PCIe x8 slot that runs at PCIe 2.0 x4 electrical speeds. This is great since it does provide additional configuration options either for additional network or storage.

ASUS P9A-I-C2550-SAS-4L-PCIe Slot
ASUS P9A-I/C2550/SAS/4L PCIe Slot

Next to the PCIe slot is a M.2 NGFF storage port for newer solid state disks. One should be cautious though as the M.2 connector is standard but the lengths of M.2 form factor drives are not. Our Crucial M550 128GB drive did not fit due to length for example.

ASUS P9A-I-C2550-SAS-4L-M2 Slot
ASUS P9A-I/C2550/SAS/4L M.2 Slot

The large heatsink just below the memory slots is for the processor. The ASUS P9A-I/C2550/SAS/4L uses an embedded Intel Atom C2550 processor with a 14w TDP. ASUS also has a similar SKU with the eight core Intel Atom C2750. Next to the small heatsink is a 4-pin CPU power connector and two SATA ports. One of the SATA III ports is disabled if the M.2 connector is used. In this area we can also see a total of six 4-pin fan headers which is plenty for this platform.

ASUS P9A-I-C2550-SAS-4L-Processor-Power-Fan
ASUS P9A-I/C2550/SAS/4L Processor Power Fan

Likely one of the standout features of the ASUS P9A-I/C2550/SAS/4L are the dual Marvell 88SE9485 controllers. These controllers each have two SFF-8087 SAS connectors and can directly connect 8 SAS or SATA drives each. That means one has 16 SAS/ SATA ports, 1 SATA port and one SATA or M.2 port available for an easy path to connect up to 18 drives. These Marvell controllers are fairly popular but do consume 5.5w each.

ASUS P9A-I/C2550/SAS/4L-Marvell SAS
ASUS P9A-I/C2550/SAS/4L Marvell SAS

In terms of the rear I/O panel there is a legacy VGA and two USB ports which is great for KVM carts or devices like a Lantronix Spider KVM. Next to this are LED status indicators and a physical power button. Atop of the USB 2.0 ports is a LAN port for the built-in iKVM solution.

ASUS P9A-I/C2550/SAS/4L Rear I/O
ASUS P9A-I/C2550/SAS/4L Rear I/O

Perhaps one the best design decitions for ASUS was the use of the Atom SoC’s i354 quad port gigabit Ethernet NIC. ASUS uses the Marvell 88E1543 PHY much like Supermicro solutions. The drivers for this configuration are the standard Intel drivers and the i354 is now well supported. The decision to use the Intel i354 and Marvell PHY is one that is a premium solution but is proven to work well.

In terms of performance, the ASUS P9A-I/C2550/SAS/4L was in-line with our Intel Atom C2550 benchmarks. We have the C2550 in our previous STHbench.sh test script archive and it will be part of the Linux-Bench.com archive in the next few weeks as that is rolled out. One can see some examples of the processor against cloud options in the new Amazon AWS EC2 t2 instance benchmarks.

Management Features

The ASUS P9A-I/C2550/SAS/4L includes the ASMB7 management solution with provides features for remote monitoring and management. We did a deep-dive on the ASUS ASMB6 iKVM solution and it works very well. This motherboard has the next generation ASMB7 iKVM solution built-in. That ASMB6 article has much of the same functionality so it is a great place to get an overview of the ASUS management platform.

ASUS ASMB6 iKVM Remote Control - Remote KVM
ASUS iKVM Remote Control Example – Remote KVM

One management option that ASUS offers is ASWM Enterprise. We will do a full review of ASWM Enterprise in the near future. Here is a quick video on ASWM Enterprise:

Thermal Imaging and Power Consumption

For our thermal imaging tests we utilized our standard FLIR Ex series imager at 320×240 resolution with the MSX technology. This platform was extremely sensitive to power and our standard thermal testbed’s 650w Seasonic unit did not have enough load to start. We added a PicoPSU 150XT to the platform and everything worked well. One does need to be slightly careful not to oversize PSUs with these platforms.

ASUS P9A-I/C2550/SAS/4L Thermal Imaging
ASUS P9A-I/C2550/SAS/4L Thermal Imaging

Overall, results were excellent. All of the ICs stayed below required thermal limits. Just for fun, we did try cooling the system using 20db 40mm fans. This worked quite well and one fan on the CPU and another on the Marvell controllers managed to cool the system using 1.7w of power. In terms of power consumption, we saw a fairly 26.4w at idle using our Extech TrueRMS power meter (without drives.) During Linux-Bench multi-threaded runs we saw 30.2w maximum at peak. The platform benefits from having only two DIMMs but does have 11w of Marvell SAS controllers onboard.


Now for the really interesting part of the equation: price. ASUS sells the P9A-I/C2550/SAS/4L for $344. That is significantly less than buying a CPU, motherboard, 16 ports of SAS connectivity and a dual port NIC to augment onboard standard dual gigabit LAN. The other side to the equation is the operational costs which remain low due to power consumption. More DIMMs would have been good but there is no room for additional DIMM slots. Overall, this platform is going to be a strong contender for storage platforms especially with their low CPU requirements. It is certainly an interesting value proposition for those in the market for this class of embedded option and therefore receives very high marks.

This is certainly going to be a popular platform and we will give it an extended test when we get back from Bali!


  1. Congratulations in advance on your wedding!!! Turn off, tune out, and focus on what’s important (psst… it’s your Bride). 🙂

  2. I am just wondering WHERE they sell these boards for $344. I can get them through a local Aussie retailer for double that amount…. but that’s a massive extra slug for the privilege of buying it from a local supplier.

  3. What storage-specific benchmarks will you be throwing at this? I’m interested in things like iSCSI performance, software-raid reconstruction times, etc. Would be interested to run a similar suite against my existing (and probably over-spec’ed) Xeon-based storage unit.

    I’d be really surprised if this thing has enough oomph to support 10g networking, too.

  4. From this and the post in the forums he sounds like he went to the ASUS not retailer warehouse to get. Maybe takes some time to go through channel.

    I’ve always thought he has contacts at ASUS so he maybe got before we can buy.

    I’m interested in this and that Supermicro one with the LSI SAS.

  5. Brett – there are two threads in the forums. One says he is on honeymoon. Another asks for tests to run. Maybe post in the test one and see if he can run back to back on diff platforms?

  6. This looks like it might be a great option for a home media server. I’ve been looking for a case like the NORCO RPC-4224 to use with this, but I can’t fit a full-depth case in my rack – need something no deeper than about 20″. Anyone know of a shallow-depth rackmount case with a ton of drive bays?

  7. I am looking for the exact same requirements in a home media case, and have not had any luck finding anything that fits my requirements. I’ve given up looking, and am just designing my own. Preliminarily, it looks like I can get 6 3.5″ drives* and a mitx mobo (using a picopsu) into a 1U case that is only 15″ deep. I’m still in the design phase, but once I get a final design I plan on posting the drawings for other people to use.

    *I’m aiming for a fanless case, but with active cooling I could probably fit 10-12 3.5″ drives.

  8. This looks perfect. Too bad it’s not available in the USA (although I suppose I could have it shipped, but the shipping would probably be more than the cost of the item). Hopefully someone here will start importing these or making a version for sale by US outlets.

  9. This is interesting but very pricey and I’d have to have a separate enclosure for the computer to drive it. I wonder why the price is so high relative to something like the Norco 4224?

  10. So, what are your storage requirements? I actually bought a 4224, and now I’m somewhat regretting it. I think I’d rather just have a couple of smaller ones, like 8-bay 2u’s, etc.

    The thing I’m really annoyed by the 24-bay case is finding a controller to drive all the bays.

    If this platform could handle, say, 8 drives in raid6-like modes, it’d be interesting to see how it fared w/ stuff like Ceph, etc.

  11. Assuming this ASUS board becomes available at retail sometime, it has 4 SFF-8087 connectors and an add-in board like the HighPoint RocketRAID 2680 SGL: http://www.newegg.com/Product/Product.aspx?Item=N82E16816115096 could be added to provide two more, so that takes care of the six drive connections. My plan would be to just set up JBOD and use DriveBender for storage pooling. To your point I don’t really need 24 bays worth of storage at the moment but since I keep outgrowing storage servers this setup should hold me for a while. Of course the whole thing is a pipe-dream if this board never comes to retail and if I can’t find a short-depth storage case that takes mini-ITX.

  12. Great looking motherboard.

    Are you going to test to one without SAS and the C2750 one??? Hope you do. I will order a few of these when they come available.

  13. This motherboard very good. I too want to see C2750 and non-sas versions. $344 great price. C2750 at $400 even better. Wonder how much less the C2550 no SAS is?

    Like review very much good.

  14. For anyone else who is seeking this info, I checked the manual on ASUS’s website and the M.2 port requires one of the 42mm length (aka “2242”) M.2 NGFF drives. For what it’s worth, when I did a search for 2242 SSDs I found there are currently not very many to chose from.

  15. Having a lot of problems with the mb and Debian. Drives (WD Red/Green mix) dropping out constantly. Set up as JBOD, so this isn’t a RAID issue per se. Curious if anyone else has similar problems. Hotplug also doesn’t work properly with recent Linux kernels, the mvsas driver is not exactly well-baked.

  16. Would love to see benchmarks posted. On my P9A-I , I am getting about 50% of the memory bandwidth of the Gigabyte and non-Asus motherboards. In particular, stream/triad is running at 50%.

    BIOS problem? Memory controller misconfigured?

  17. Hi – just wondering how this would compare to my current setup of xeon L3426 with Supermicro X8SIL-F with 10GB ram. I am also using a cheapo Highpoint SAS card to have more hard drives in JBOD.

  18. Hi Patrick – Sorry I should have clarified – in terms of performance what can I typically expect. Every now and again I use handbrake to reduce file size for media files, but the primary usage for the box is a NAS function. I believe the asus will have a much smaller footprint for power consumption.

  19. have you seen the Highpoint rocket 750 (40 ports)

    I have one in the supermicro mini-atx c2758 board with 30 drives , 24 2.5″ wd red 1tb and 6 ssd’s and icy dock 6 drive racks , ZFS for raid Ubuntu trusty 20TB runs under 100 watts loaded total as measured with my kill a watt
    root@myth-be-01b:/var/lib/mythtv/scripts# zpool status
    pool: pool1
    state: ONLINE
    scan: resilvered 229G in 3h2m with 0 errors on Tue Sep 16 06:03:49 2014

    pool1 ONLINE 0 0 0
    raidz2-0 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX11A74APDH6 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX11A74APUL2 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX21A74KNAT3 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX21A74KNLP5 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX21A74KNT2R ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A6415CS5 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A6415ET9 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A645U4PS ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A645UD53 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A645UL5P ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A645US34 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WX81A645UTCL ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WXA1A64FL5D7 ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WXA1A64FLR1X ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WXD1A64FA2LL ONLINE 0 0 0
    ata-WDC_WD10JFCX-68N6GN0_WD-WXD1A64FARH0 ONLINE 0 0 0
    mirror-1 ONLINE 0 0 0
    ata-KingFast_SZHYPO14061207B0206-part1 ONLINE 0 0 0
    ata-KingFast_SZHYPO14061207B0107-part1 ONLINE 0 0 0
    ata-TRO-SSD7-120GB_EL140725AS1475251-part2 ONLINE 0 0 0

    errors: No known data errors

    pool: pool2
    state: ONLINE
    scan: none requested

    pool2 ONLINE 0 0 0
    mirror-0 ONLINE 0 0 0
    ata-WDC_WD5000BEVT-00ZAT0_WD-WXNX08N14811 ONLINE 0 0 0
    ata-WDC_WD5000BEVT-22A0RT0_WD-WXA0AA9M6048 ONLINE 0 0 0
    mirror-1 ONLINE 0 0 0
    ata-KingFast_SZHYPO14061207B0107-part2 ONLINE 0 0 0
    ata-KingFast_SZHYPO14061207B0206-part2 ONLINE 0 0 0
    ata-TRO-SSD7-120GB_EL140725AS1475251-part1 ONLINE 0 0 0
    ata-WDC_WD5000BEVT-22ZAT0_WD-WXNX08S84875 AVAIL

    errors: No known data errors

    pool: pool3
    state: ONLINE
    scan: resilvered 12.1G in 0h2m with 0 errors on Thu Sep 25 19:09:52 2014

    pool3 ONLINE 0 0 0
    mirror-0 ONLINE 0 0 0
    ata-TRO-SSD7-120GB_EL140725AS1475667-part2 ONLINE 0 0 0
    ata-TRO-SSD7-120GB_EL140725AS1475614-part2 ONLINE 0 0 0
    mirror-1 ONLINE 0 0 0
    ata-KingFast_SZHYPO14061207B0107-part3 ONLINE 0 0 0
    ata-KingFast_SZHYPO14061207B0206-part3 ONLINE 0 0 0
    ata-TRO-SSD7-120GB_EL140725AS1475453-part2 AVAIL

    errors: No known data errors

  20. Hi Patrick,

    if you want to try the ASUS P9A-I with total 32GB of memory, please contact me.
    We distribute the Intelligent Memory 16GB ECC UDIMMs for this (and other) motherboards.
    The Atom C2000 series is one of the rare Intel CPUs supporting 16GB UDIMMs, while most other Intel processors have a ‘software limitation’ by the MRC in the BIOS to take maximum 8GB per module.
    On Non-Intel branded CPUs there is no such limitation…really strange.

  21. Please try this, I’ve always been interested, am about to buy memory for this board, and it would make an interesting article.

    Thorsten, if Patrick doesn’t bite give me a holler. I’d be happy to test it out 🙂

  22. Based on this review I bought the P9a-i.

    So far:

    Impossible to get it to boot off USB to install. Verified security disabled but no fix.

    Both Win 7 64 and 2012 R2 demand drivers during installation to proceed. None of the drivers provided on the disk nor on their website work.

    Was able to install Unbutu 14.04 without a hitch.

    Called ASUS support and they just blinked.

  23. Also having issues on openmedia vault which I believe is running a Debian kernel.

    Seems stable with 3 drives per sas cable but flakes out when I add more drives and raid is always having to rebuild . is there a better module than the nvsas? I noticed a nv94xx driver on Asus site. Is this the same thing? No specific build of it for Debian though. Thoughts?

  24. This motherboard is total trash. I bought one thinking thats its perfect for any type of nas or storage box you want to build. 4 nics + lom, onboard sas controller, fanlezs, etc = GOOD GOD DROOL!!!!!

    To bad this mobo does not work with anything, hates storage cards added to the pice slot, cant boot off usb, cold boot issues, wonky lom and a host of all other issues.

    Too good to be true = yup


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