The Polywell Poly Z390L2-i9 small-form-factor desktop looks like a brick of gold that you'll want to keep locked in a bank vault.
You won't need a vault because of the priceless value of the Polywell (starts at $689; $995 as tested) or its shiny gold exterior.
No, you'll need a locked vault because of the sheer noise the system makes from the moment it boots up until the moment you shut it down.
The Poly's cooling fan runs constantly and at great volume that obviates the chief advantage of a micro PC—the ability to keep it on the corner of your desk or tucked behind your monitor when you're short on space.
Perhaps with a less powerful and power-hungry CPU than the eight-core Intel Core i9-9900 in my review unit, the system would operate at a more reasonable sound level.
Polywell deserves props for getting a desktop Core i9 into a box this small, but given our review unit, we'd prefer a little less power in exchange for a lot less noise.
Swiss Cheese Design
The Poly Z390L2-i9 is available in either plain black or the attention-grabbing gold of my test model.
Each side of the case features a great deal of venting, and four of the six sides (all but the front and back panels) feature prominent ridges that lend the system the appearance of a huge heat sink.
The ridges also make the machine uncomfortable to pick up—the edges are painfully spiky.
The chassis measures 2.2 by 8.1 by 8.1 inches, which is certainly compact for a desktop but in the middle of the SFF spectrum.
The Lenovo ThinkCentre M720q Tiny is thinner and smaller at 1.4 by 7 by 7.2 inches, while the boxy Asrock DeskMini 310 is thicker but even more compact at 3.2 by 6.2 by 6.2 inches.
Though in the middle of the road in terms of size for a micro desktop, the Polywell is at or near the top for the number and variety of ports it offers.
A pair of USB Type-A ports sits on the front panel below the power buttons.
The rest of the ports are on the back panel.
You get one DisplayPort and two HDMI video outputs.
There are five USB 3.0 ports and two USB 2.0 ports along with a USB-C port; two Gigabit Ethernet ports; and two connectors for the included Wi-Fi antennas.
Also back here are three audio ports (line-in, line-out, and mic-in) and even a PS/2 port if you want to connect an ancient keyboard or mouse.
That's greater and more varied connectivity than you'll find on most full-size PCs.
Cramped Quarters
It should come as no surprise when I tell you that the Poly Z390L2-i9 doesn't provide much in the way of interior expansion.
Remove four screws, lift off the top panel, and you'll find two DIMM slots (both occupied in my eval unit), a free PCI Express x16 slot, and room for a 2.5-inch hard drive or SSD.
Though you'll see a full-length PCI Express slot here on the motherboard, under the hard drive bay, you can't use it.
Not even a low-profile card will work here, as there's no cutaway for the backplane of the card in the case, and the power-in jack's internal cabling would get in the way.
It's no major loss, I suppose—even with all the venting the chassis provides, the cooling fan on my sample ran constantly.
Adding a component that restricts airflow would only tax the cooling system further.
Beneath the cooling fan and heatsink under the hood lurks an Intel Core i9-9900, a 3.1GHz (5GHz turbo) "Coffee Lake" processor with eight cores, support for up to 16 threads, and a thermal design power (TDP) rating of 65 watts.
The system's 16GB of memory comes by way of two 8GB modules.
A 500GB PCI Express/NVMe solid-state drive loaded with Windows 10 Home takes care of storage.
Without a dedicated graphics card, the PC relies on the processor's integrated Intel UHD Graphics 630.
Keeping thermals in check for the above internals required an aggressive approach.
The cooling fan, which resembles Intel's stock fan for its mainstream CPUs, ran nonstop during the course of this review, whether the system was running benchmarks, streaming videos, or sitting idle.
As you'll see in the next section, the Z390L2-i9 turned in blazing performance, but the noise you're required to put up with isn't worth the trouble.
There's not a video cable long enough to keep the Poly out of earshot, which is too bad because it's an able performer.
Even before it proved its mettle in labs testing, it handled multitasking scenarios without any hiccups and smoothly streamed HD videos.
Over-the-Top Performance
For our objective benchmark tests, I pitted the Polywell against four other consumer-grade SFF PCs, including the Core i5-based Azulle Inspire Mini PC and Lenovo ThinkCentre M720 Tiny, and the Core i7-based Intel NUC Kit (NUC8i7HVK "Hades Canyon").
I also included the Xeon-powered HP Z2 Mini G4 workstation, which comes loaded with 32GB of RAM and Nvidia Quadro P1000 graphics.
Productivity, Storage & Media Tests
PCMark 10 and 8 are holistic performance suites developed by the PC benchmark specialists at UL (formerly Futuremark).
The PCMark 10 test we run simulates different real-world productivity and content-creation workflows.
We use it to assess overall system performance for office-centric tasks such as word processing, spreadsheet jockeying, web browsing, and videoconferencing.
The test generates a proprietary numeric score; higher numbers are better.
PCMark 8, meanwhile, has a storage subtest that we use to assess the speed of the PC's storage subsystem.
This score is also a proprietary numeric score; again, higher numbers are better.
The Poly Z390L2-i9 turned in a positive result on PCMark 10, even edging the Xeon-based HP workstation.
However, it trailed the Intel NUC8i7HVK, which uses a high-end mobile Core i7 CPU.
I would trade the Core i9 for such a part, not so much for the performance but because a more efficient mobile processor might require a less aggressive cooling system.
The PCMark 8 Storage score was right-on for a PC with a solid-state PCI Express boot drive.
Next is Maxon's CPU-crunching Cinebench R15 test, which is fully threaded to make use of all available processor cores and threads.
Cinebench stresses the CPU rather than the GPU to render a complex image.
The result is a proprietary score indicating a PC's suitability for processor-intensive workloads.
With its eight cores and 16 processing threads, the Core i9 CPU was able to flex its muscle on Cinebench and allowed the Z390L2-i9 to cruise to an easy victory.
Cinebench is often a good predictor of our Handbrake video-editing trial, another tough, threaded workout that's highly CPU-dependent and scales well with cores and threads.
In it, we put a stopwatch on test systems as they transcode a standard 12-minute clip of 4K video (the open-source Blender demo movie Tears of Steel) to a 1080p MP4 file.
It's a timed test, and lower results are better.
The Polywell also posted a super-fast time in Handbrake, completing its taskwork minutes faster than the next closest competitor.
We also run a custom Adobe Photoshop image-editing benchmark.
Using an early 2018 release of the Creative Cloud version of Photoshop, we apply a series of 10 complex filters and effects to a standard JPEG test image.
We time each operation and, at the end, add up the total execution time.
As with Handbrake, lower times are better here.
Another media test, another first-place finish for the Poly Z390L2-i9.
It made quick work of our Photoshop test and easily finished with the fastest time.
Graphics Tests
3DMark measures relative graphics muscle by rendering sequences of highly detailed, gaming-style 3D graphics that emphasize particles and lighting.
We run two different 3DMark subtests, Sky Diver and Fire Strike, which are suited to different types of systems.
Both are DirectX 11 benchmarks, but Sky Diver is more suited to laptops and midrange PCs, while Fire Strike is more demanding and made for high-end PCs to strut their stuff.
The results are proprietary scores.
The Poly Z390L2-i9 posted decent scores for a system with integrated graphics, but finished well off the pace of the Intel NUC and its onboard AMD Radeon RX Vega M GH graphics, as well as the HP Z2 Mini G4 and its Nvidia Quadro P1000 graphics.
Without the ability to house a full-size graphic card, the Polywell won't be confused with a gaming PC.
Turn Down the Noise
At what cost blazing application and multimedia performance inside a SFF PC? The Polywell Poly Z390L2-i9 puts its Core i9 processor to good use, tearing through labs testing and multitasking scenarios with ease.
Well, not with ease exactly.
The system handily beat competing micro desktops, but needed its cooling fan to spin constantly in order to keep its thermals in check.
As configured, the Z390L2-i9 simply creates too much of a racket to keep on your desk—or anywhere near it.
The Bottom Line
The Polywell Poly Z390L2-i9 is a speedy performer—and wildly small for a Core i9 desktop PC—but you won't want to sit anywhere near it and its raucous cooling fan.
