Nowadays there are loads of small form-factor (SFF) systems featuring fairly high performance, there are also fanless PCss that can offer performance of regular desktops. Unfortunately, SFF and fanless worlds rarely intersect and passively cooled compact desktops are extremely rare. Yet, they exist. Recently Atlast! Solutions introduced its Sigao Model B, which packs Intel's 10-core Comet Lake CPU into a fairly small fanless chassis.
The Atlast! Sigao Model B is based around Intel's 10-core Core i9-10900T processor as well as an Asus H470-I Mini-ITX motherboard. The CPU features a 35W TDP and has a base clock of 1.9 GHz as well as a maximum turbo frequency of up to 4.6 GHz, though we would not expect the processor to hit very high clocks in a fanless system powered by a 200W PSU. The motherboard comes with all the essentials, including Wi-Fi 6 and Bluetooth module, two Gigabit Ethernet ports, three display outputs (DisplayPort, HDMI, USB 3.2 Gen 2 Type-C), one USB 3.2 Gen 2 Type-A connector, four USB 3.2 Gen 1 Type-A ports, and 5.1-channel audio.
The Sigao measures 12.6 x 12.6 x 3.4 inches (320 × 322 × 87.5 mm) without feet, so while it is definitely not as compact as Intel's NUC or Apple's Mac Mini, it can still be considered a small form-factor PC.
Atlast! builds its fanless systems to order, so it can equip its Sigao Model B with up to 64GB of DDR4-2666 memory, one Samsung 970 Evo Plus M.2 SSD with a PCIe 3.0 x4 interface and up to 2TB capacity, and two 2.5-inch HDDs or SSDs.
The motherboard has a PCIe 3.0 x16 slot and the system can accommodate a single slot wide add-in card using a riser, though finding a decent mini-ITX 75W single slot graphics card with passive (or even active) cooling is close to impossible, so it is unlikely that the system can be equipped with a standalone AIB. Unfortunately, the motherboard also lacks a Thunderbolt 4 port for an external graphics solution, so it looks like the Sigao Model B has to rely on Intel's built-in UHD Graphics 630 based on the previous-generation architecture. Meanwhile, if the Asus H470-I motherboard gains Rocket Lake-S support, it should be possible to install a more up-to-date CPU with Xe Graphics featuring leading-edge media playback capabilities.
The Atlast! Sigao Model B is not cheap at all. Even the basic model featuring a Core i9-10900T, 16GB of RAM, and a 250GB SSD costs €1,922 ($2304) with taxes and €1,602 without ($1,920), which is quite expensive even by SFF standards. But a desktop PC that brings together compact dimensions and passive cooling is hard to come by, so its price seems to be justified for those who want both features.