Workstation Review: @Xi MTower CX

The Xi MTower CX workstation is a powerful over-clocked system in a curious cube-like case.

The Xi MTower CX workstation is housed in a rather distinct Corsair Carbide Series AIR240 case, which has no externally accessible drive bays. Image courtesy of @Xi Computer.

Xi Computer The Xi MTower CX workstation is housed in a rather distinct Corsair Carbide Series AIR240 case, which has no externally accessible drive bays. Image courtesy of @Xi Computer.

Last year, California-based @Xi Computer Corporation (pronounced “at-ex-eye”) shipped us an updated version of its over-clocked tower PCIe workstation. This time around, the company sent us something different. Unlike traditional towers, which are typically tall and narrow, the Xi MTower CX workstation that arrived at our test lab was nearly a cube. And its shape proved to be just one of its unique qualities.

Housed in a Carbide series AIR240 case manufactured by Corsair, the Xi MTower CX measured 10.2x15.6x12.6 in. (WxDxH) and weighed in at 23 lbs. The front panel is split almost equally down the center. Six air intake grilles with the @Xi logo in the center fill the left side and conceal a radiator with a pair of 120mm fans, while a nearly blank panel occupies the space on the right. An illuminated power button sits nearly centered in the blank panel, flanked by a reset switch and hard drive activity light to its left, with microphone and headphone jacks and a pair of USB 3.0 ports to the right. There is no provision for any front panel drive bays—the first time we have ever seen this (or the lack thereof) on anything other than a mobile workstation.

The front panel air grilles appear to wrap around onto the top of the case where they conceal a second pair of 120mm fans. Removing the top panel reveals three SSD (solid-state drive) bays with removable plastic trays. Removing a cover on the rear panel exposes three similar bays for 5.25-in. hard drives. There is yet a fifth fan behind the rear panel.

The rear panel also provides a PS/2 mouse/keyboard port, two USB 2.0 ports, a USB BIOS flashback button, two USB 3.1 ports, four USB 3.0 ports, two RJ45 network jacks, an optical S/PDIF out port and five audio jacks including line-in, line-out/front speaker out, microphone, center/subwoofer and rear speaker out. The NVIDIA graphics card in our evaluation unit also provided four DisplayPorts, a DVI-I connection, and a 3D stereo jack.

Xi Computer The rear panel of the Xi MTower CX workstation provides lots of expansion options. A removable panel reveals three 5.25-in. drive bays. Image courtesy of David Cohn.

While built-in Wi-Fi is something not typically found in workstations, the Xi MTower CX breaks that rule as well. The ASUS X99-M WS motherboard provides 802.11 a/b/g/n/ac and supports dual-band frequencies of 2.4 and 5GHz as well as Bluetooth 4.0. Three tiny jacks on the rear panel provide connections for a small external antenna with a 30-in. cable that you can place on top of the computer or on your desk.

Abundant Options

The Xi MTower CX has a base price of $1,199. That buys you a quad-core Xeon CPU, 4GB of RAM, an entry-level NVIDIA NVS graphics card, 500GB hard drive, keyboard and mouse. But as we have come to expect from @Xi, there are lots of options. For example, you can choose any of eight different CPUs and our evaluation unit was equipped with an eight-core Intel Xeon E-1660 v3 Haswell processor. Although this CPU typically runs at 3.0GHz, with a maximum 3.5GHz turbo speed, ours came over-clocked to 4.1GHz and cooled using a Cooler Master sealed water cooling system with its dual fan radiator concealed behind the front panel (adding $1,399 to the system price).

Instead of a solid panel, the left side of our Xi MTower CX case included a clear plastic window, providing a view of the inside. The internal space is split by a backplane, which aligns with the division of the case’s front panel. You can remove the left side panel to access the half housing the motherboard and the right side panel to access the power supply and a fair amount of empty space. Due to the power demands of our system, @Xi included an 850 watt Rosewill Glacier 850M 80 Plus Bronze certified power supply, which added $65 to the overall cost.

The motherboard includes a single LGA2011-v3 processor socket flanked by four DIMM (dual in-line memory module) slots. Although the system supports up to 64GB of unbuffered or ECC memory, our unit came with 16GB, installed as a pair of 8GB Corsair Vengeance LPX 2666MHz modules (adding $109).

There are also three PCIe X16 3.0 expansion slots and one PCIe 2.0 slot. @Xi offers a choice of 17 different NVIDIA graphics boards. Ours included an NVIDIA Quadro M5000 GPU (graphics processing unit) installed in one of the PCIe 3.0 slots. Based on NVIDIA’s latest Maxwell architecture, the Quadro M5000 features a 256-bit interface and provides 8GB of dedicated GDDR5 memory and 2048 CUDA (compute unified device architecture) parallel processing cores while delivering a bandwidth of 211GB/sec. Because the M5000 consumes up to 150 watts, it requires an auxiliary power connection. Its thickness also means that it blocks the adjacent PCIe 2.0 slot, with the board’s optional 3D stereo connector routed to the adjacent rear panel bracket. The M5000 added $1,659 to the system price. The Xi MTower CX can accommodate up to two Quadro boards, or one GPU and an NVIDIA Tesla board.

Storage choices include conventional hard drives of up to 4TB as well as solid state drives ranging from 250GB to 2TB. For our review, @Xi included a 256GB Samsung M.2 PCIe 3.0 solid state drive ($229) hosting the operating system and a 1TB 7200rpm Seagate Barracuda SATA drive for data storage (a $29 upgrade from the base configuration).

Although the case makes no provision for an optical drive, ­ @Xi sells external USB DVD-Writer and Blu-ray Writer drives for $69 and $119, respectively. But we found the identical drives from other online retailers at $24 and $80.

Blazing Performance

With its SSD, the @Xi workstation booted up very quickly. But its seven fans (including those on the GPU and power supply) and a case lacking acoustic damping results in a noisy system. The Xi MTower CX averaged 38dB at rest (compared to 29dB ambient background noise), increasing to 46dB during heavy compute loads (about equivalent to a typical office conversation).

Thanks to the NVIDIA Quadro M5000 GPU, the Xi MTower CX workstation performed great on the SPECviewperf benchmark, turning in some of the best results we have ever recorded for a single-socket workstation. On the AutoCAD rendering test, which clearly shows the benefits of multiple fast CPU cores, the Xi MTower CX blew us away, completing the test in 25.3 seconds—faster than any single socket workstation we have ever tested. And on the SPECwpc benchmark, the Xi MTower CX scored at or near the top on every component of this very demanding test.

For our SOLIDWORKS tests, we have recently begun using the SPEC SOLIDWORKS 2015 benchmark. This new evaluation performs nine graphics tests and two CPU tests. Although we have run this test on several mobile workstations, this marks the first time we have done so on a full-fledged workstation. While we therefore have nothing similar to compare it to, the Xi MTower CX turned in excellent results on this new real-world performance evaluation. For comparison’s sake, we included the SPEC SOLIDWORKS 2013 benchmark results on page 44.

Although Windows 10 Home is included in the Xi MTower CX base price, for our review @Xi pre-installed Windows 7 Professional Edition 64-bit, adding $179 to the overall cost. Customers can also purchase their system without an operating system or choose Windows 8.1, Windows 10 Professional, or one of eight different versions of Linux. A free one-year license to McAfee AntiVirus Plus as well as one-year usage of the SplashID 8 Pro password manager software is also included. @Xi rounded things out with a Logitech 104-key keyboard and Logitech USB 2-button wheel mouse, but here again, the company offers lots of other options.

The standard Xi warranty includes just one-year coverage on system parts and three years for labor. We always find this type of coverage a bit puzzling, since most of the actual components (hard drive, graphics card, etc.) come with their own three-year warranties. @Xi offers warranties up to five years, and included a full three year parts warranty on our system (a $129 option).

Once all of the extras were tallied, our evaluation unit priced out at $4,997. Considering that price is less than other over-clocked systems we’ve tested yet beat their performance, the MTower CX once again proves that @Xi delivers plenty of bang for your buck.

More Info


Single-Socket Workstations Compared

Xi MTower CX one 3GHz Intel Xeon E5-1660 v3 8-core CPU over-clocked to 4.1GHz, NVIDIA Quadro M5000, 16GB RAMBOXX APEXX 2 2401 one 4GHz Intel Core i7-4790K 4-core CPU over-clocked to 4.5GHz, NVIDIA Quadro K5200, 16GB RAMDigital Storm Slade PRO one 3.1GHz Intel Xeon E5-2687W v3 10-core CPU, NVIDIA Quadro M4000,



Direct Volta Pro one 4GHz Intel Core i7-4790K quad-core CPU, NVIDIA Quadro K5200,


Xi MTower PCIe one 3.7GHz Intel Core i7-5930K 6-core CPU over-clocked to 4.32GHz, NVIDIA Quadro K5200, 16GB RAMLenovo P300 one 3.6GHz Intel Xeon E3-1276 v3 quad-core CPU, NVIDIA Quadro K4000, 8GB RAM
Price as tested$4,997$5,806$6,187$4,441$4,985$2,072
Date tested1/25/161/30/1610/18/157/12/1512/13/1411/9/14
Operating SystemWindows 7Windows 7Windows 10Windows 7Windows 8.1Windows 7
SPECviewperf 12 (higher is better)
SPECapc SOLIDWORKS 2013 (higher is better)
Graphics Composite2.833.202.1611.248.826.29
RealView Graphics Composite3.644.112.7713.3210.036.88
Shadows Composite3.694.172.8013.3710.056.89
Ambient Occlusion Composite8.489.576.4428.0817.589.65
Shaded Mode Composite2.773.132.1011.258.956.17
Shaded with Edges Mode Composite2.903.282.2111.228.696.41
RealView Disabled Composite1.041.180.805.695.284.39
CPU Composite4.925.113.394.874.504.18
Autodesk Render Test
Time in seconds (lower is better)25.3041.8847.3350.8342.3364.08
SPECwpc v2.0 (higher is better)
Media and Entertainment3.843.523.67n/an/an/a
Product Development3.383.063.89n/an/an/a
Life Sciences4.193.654.46n/an/an/a
Financial Services2.591.542.55n/an/an/a
General Operations1.781.991.47n/an/an/a

Numbers in blue indicate best recorded results. Numbers in red indicate worst recorded results.

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About the Author

David Cohn's avatar
David Cohn

David Cohn is a consultant and technical writer based in Bellingham, WA, and has been benchmarking PCs since 1984. He is a Contributing Editor to Digital Engineering, the former senior content manager at 4D Technologies, and the author of more than a dozen books. Email at [email protected] or visit his website at

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