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Hello,

Planning my first ever SFFPC build as the Lenovo M715q didn't really live up with upgrade-ability expectations for the similar role. Thought that I might as well create a thread here ahead of time while I'm slowly ordering components to get some early comments (asked in the reddit component thread, but as I understand those are recycled). Goals for the build:

• Must fit in the backpack with ease as traveling on the go very often. Reasonable weight as well.
• All around functionality to exclude the need for other devices, mostly compiles, math CPU loads (R), light gaming once in a blue moon (think Xonotic, WC3, etc).
• APU to cut on the GPU power, space and weight requirements, no need for AAA+ gaming or something.
• Still some gaming or otherwise GPU work in mind, therefore AMD all the way due to performance and driver reasons (Linux).
• Ability to power up from the car cigarette lighter socket is a huge "nice to have" (EV driver here, you don't always get a café to sit, also CANbus development is much easier if you can actually sit in the car).
• Another "nice to have" is some sort of UPS, not meant to allow full power for hours like laptop, but rather survive an accidental power cord disconnect, switch sockets to another table, save all stuff and power off correctly in actual outage and so on.

Components in mind so far (will update with prices and links as time goes):

Part	Choice	Price, $	Comments
APU	Ryzen 7 4750G	$ 345.75 (9700 ₴)	Seems to be crème de la crème at the moment, 65 W TDP, somehow available for retail in Ukraine I probably don't want to know
Motherboard	Gigabyte B550I AORUS PRO AX	$ 197.11 (5530 ₴)	No-BS rear ports selection, apparently one of the best of B550I bunch when it comes to thermals, the chipset allows PCIe 4 on the main M.2 slot and the PCIe port and seems to give an upgrade path to a future Zen 3 APU before AM4 / DDR4 are outdated.
RAM	16Gb x 2 (32Gb Kit) DDR4, 3200 MHz, G.Skill Aegis, 16-18-18-38, 1.35V	$ 117.41 (3294 ₴)
Storage	Samsung PM981 NVMe M.2	$ 69.44 (76.56 €)	Recycled from the Lenovo, bought at compuram.de, no longer available there.
Case	M350 in silver	$ 35	Good reviews, no extras I won't use, front USB "pouch" usable for a 4G modem that won't stick out.
CPU cooling	Noctua NH-L9A-AM4	$ 39.73 (£ 29.92)	No real competition due to 37 mm height, everyone uses them as far as I see.
System fan 1	Noctua NF-A4x10 PWM 12V	$ 15.50 (£ 11.67)	Not sure if 20 mm will fit for the front panel mounting place.
System fan 2			Still deciding how to mount and whether I need it
	Anti-Vibration Silicone Washers	$ 1.22 (£ 0.92)
Power supply	picoPSU-160-XT + 192W mini-box's AC/DC	$ 89	12 V allows to cut redundant DC-DC conversions, including car power (15A fuse, 180W). 160W/200W peak must be enough without a discrete GPU to my amateurish mind and it's the highest power picoPSU anyway.
UPS	OpenUPS2		Fits the top bracket so can stay inside at all times, support for native battery monitoring code in Linux.
Display/Periphery for travel mode	Nexdock Touch	$ 269	Cuts the periphery clutter a lot (currently using a Kenowa 13" HDMI/USB powered display + Logitech K400+) allowing more laptop-like experience. Will also double as a terminal for RPI/SoC development and maybe for the phone as well. Also works as a power bank and a USB extender.

Current open questions:

• Can I mount a 20 mm fan for the front panel and should I?
• M.2 heatsink seems to be connected with the VRM one and that's directly above the UPS with the battery (LiFePO₄ but still), how can I utilize the second system fan connector to evacuate some heat from that part as there are no immediate mounting place?
• OpenUPS2 is rated at 5 A output which is puny 60 W @ 12 V. Going up for 24 V PSU raises it to 120 W on paper, but requires a lot of redundancy in the DCDC conversions as well as a new DCDC point in the car charger cable. MiniBox states this is because of the batteries being rated for 5A which probably rules out 120 W idea overall. There are however more discharge friendly batteries from A123 going up to 30 A, need to know if the 5 A limit is only due to the batteries and how far I can push it. Asked Mini Box about this in an email, waiting for their reply.