Mini PCs: processing power and storage capacity in a tiny form factor

Article By : Brian Dipert

How much processing power and storage capacity can be cost-effectively squeezed into a tiny form factor while still adequately addressing thermal and other constraints?

Diminutive computers have always been of particular interest to me. Just how much processing power, storage capacity, and the like can be cost-effectively squeezed into a tiny form factor while still adequately addressing thermal and other constraints? Earlier this year, for example, I tore down (although I didn’t try out in advance) an early-generation Intel Compute Stick. Then there are the multiple generations’ worth of Apple Mac mini systems I’ve used over the years, both PowerPC- and x86-based, with a successor to the latter still sitting in its box and (so far) unused.

And then there are the multiple x86-based but Windows-powered systems I’ve successively placed into service, which are the primary focus of this particular blog post. First off was the Giada Cube-N3 that I’d bought for $124.99 in mid-2011, with dimensions of 7.64″W x 5.35″D x 2.17″H, and based on a 1.6 GHz Intel Atom 330 CPU paired with an NVIDIA Ion chipset containing a Geforce 9400M graphics processor core:

Giada Cube-N3

Next came Foxconn’s nT-i2847 bought in mid-2014 for $109.99, based on Intel’s 1.1 GHz Celeron 847 CPU and with dimensions of 7.48″W × 5.31″D × 0.98″H, and which remains my in-use Windows Media Center server to this day:

Foxconn nT-i2847 back

Foxconn nT-i2847 ports

Which brings us to today’s successor, the XCY X30 based on Intel’s 1.8 GHz (3 GHz peak) Core i7-4500U, which I recently acquired for $135 (as with the others, this is a “barebones” system whose price does not include RAM, an SSD, or an operating system license, mind you). Its dimensions are 5.35″W × 4.92″D × 1.69″H, and here are some overview shots:

XCYX30 mini PC front

XCY X30 back

XCY X30 side

Here’s the companion power supply:

XCY X30 power supply

I’ve currently got Windows 10 Professional installed on it (Windows 7 and 8, as well as Linux, are also supported … MacOS too?); here it is powered up:

And here’s the startup screen:

XCY X30 display

First off, let’s discuss CPUs. In my earlier coverage of the Foxconn nT-i2847, I noted that although on paper it would seem to be slower than its Giada Cube-N3 precursor (since it was running a CPU only 2/3 the clock speed and with half the virtual cores of the predecessor), the Celeron 847 actually ran rings around the Atom 330 thanks to generational architecture advancements. The same goes for the XCY X30’s Core-i7 4500U versus both its predecessors, as this table shows:

CPU Base clock speed Max turbo clock speed # of physical cores # of virtual cores Geekbench 5 score (single-core) Geekbench 5 score (multi-core)
Atom 330 1.6 GHz 1.6 GHz 2 4 86 199
Celeron 847 1.1 GHz 1.1 GHz 2 2 201 382
Core-i7 4500U 1.8 GHz 3 GHz 2 4 586 1229

Secondly, let’s discuss memory and mass storage. To begin, here’s an internal view of one side of the PCB both after initial removal of the bottom panel and after subsequent removal of front and rear panels:

XCY X30 inside

XCY X30 no panels

The XCY X30 accepts up to 8 GBytes of DDR3L SDRAM running at up to 1600 MHz (i.e. PC3-12800), in a 204-pin SoDIMM module form factor. Here’s a closeup of the memory socket:

SoDIMM socket

I picked up a used 8 GByte PC3-12800 SoDIMM off Ebay for $18.69, which works great:

SoDIMM front

SoDIMM back

The XCY X30 also supports two mass storage options, both of which can optionally find use at the same time. Here’s a closeup of the mSATA connector (at top) with a mini PCIe aka PCI Express Mini Card connector (useful, for example, with a Wi-Fi and/or Bluetooth adapter module) below it:

XCY X30 mSATA mPCIE

And here’s a closeup of the SATA data and power connectors on the motherboard, along with mounting holes for a SATA drive on the inside of the bottom chassis panel (stay tuned for what those other four holes, symmetrically located around the air flow vents, are for):

XCY X30 SATA connectors

XCY X30 bottom inside

My only to-date experience with integrated flash memory, aside from in the form of one or multiple components directly soldered on the PCB, was with the eMMC form factor found (for example) in my Acer Aspire One Cloudbook. mSATA, conversely, leverages the full SATA command set and bandwidth potential, just in a shrunk-down interface format, and is therefore capable of much higher performance. I picked up a brand new 500GB Samsung MZ-M5E500BW mSATA SSD on Ebay for $85; here’s what it looks like:

XCY X30 mSATA

XCY X30 mSATA back

And here’s what the SSD and memory look like when installed:

XCY X30 memory installed

While I still may someday also mount a SATA drive in the system, particularly if I try to turn it into a Hackintosh and therefore want to boot Windows and MacOS off different drives, for now I’m bothered by the fact that doing so would completely block those air flow vents. Conversely, I’ve taken a completely different tack … augmenting those same vents with an active fan to assist in keeping the circuitry inside cool. The mounting holes I mentioned before, along with available internal space, correspond to a 60×100mm fan, a StarTech-branded example of which I bought for $8.51 on Amazon. Here it is:

StarTech fan

StarTech fan back

And here’s the corresponding TX3 power-and-control connector for it on the motherboard:

XCY X30 fan connector

I’d fortunately earlier had a tiny M2 screw on hand to mount the mSATA SSD to the motherboard, but my M3 screws in inventory were all too short. Therefore, after first confirming that my screw dimension assumptions were correct via a $8.50 plastic gauge:

plastic gauge

plastic gauge back

I then picked up an $8.99 320-piece set of M3 nuts, bolts, and screws in various lengths, which included an Allen wrench and official-looking documentation:

screws package

screws

allen wrench certificate

allen wrench guarantee

Here’s what the fan looks like installed, from two different vantage points:

fan installed

fan outside view

Careful viewers may have already discerned that I’ve got the fan mounted upside-down from its usual orientation. Normally, it would blow air away from the CPU and out of the enclosure. But in this particular situation, it would be blowing the air downward , with what I believed would be questionable effectiveness. Instead, at least for now, I’ve chosen to use the fan to draw cooler ambient air inside and up toward the CPU and chipset on the other side of the PCB. Admittedly, however, the perhaps obvious downside to this approach is that I’ll need to make sure I’m not also pulling in dust and other particulates from whatever the computer’s resting on in the process.

Installation aside, how well does the fan work? To test cooling at full CPU utilization, I fired up a copy of HeavyLoad, which as you can see fully burdens all of the CPU’s physical and virtual cores when it’s running:

HeavyLoad

Task Manager

Resource Monitor

With the processor at rest, here’s what CoreTemp reports for junction temperature measurements:

Without the fan operating, full-load temperatures are ~25°C higher:

Conversely, with the fan on, full-load temperatures are modestly but noticeably lower:

As I continue experimenting with different fan orientations and more generally familiarizing myself more fully with the system, I’ll periodically report back my findings. Until then, I as-always welcome your thoughts in the comments!

Brian Dipert is Editor-in-Chief of the Embedded Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

Virtual Event - PowerUP Asia 2024 is coming (May 21-23, 2024)

Power Semiconductor Innovations Toward Green Goals, Decarbonization and Sustainability

Day 1: GaN and SiC Semiconductors

Day 2: Power Semiconductors in Low- and High-Power Applications

Day 3: Power Semiconductor Packaging Technologies and Renewable Energy

Register to watch 30+ conference speeches and visit booths, download technical whitepapers.

Leave a comment