Overview

The ASRock X299E-ITX/ac is a Mini ITX motherboard built around Intel's LGA2066 socket and the X299 chipset. It supports Intel Core X-series processors (Skylake-X and Kaby Lake-X) and accommodates up to 128GB of DDR4 memory across two DIMM slots. This board is one of the very few Mini ITX options ever made for the X299 platform, making it a niche but essential choice for compact high-end builds.
Equipped with one PCIe 3.0 x16 slot, two SATA 6Gbps ports, one Ultra M.2 (PCIe 3.0 x4), and a secondary M.2 slot (SATA only), the board offers reasonable storage flexibility for its size. Onboard 802.11ac Wi-Fi and Bluetooth 4.2 add wireless convenience. The VRM uses an 8-phase digital design, and the CPU power is supplied via an 8-pin plus a 4-pin EPS connector, ensuring stability under heavy loads.
Positioned in the enthusiast-to-workstation segment, this motherboard is ideal for users who insist on Mini ITX but need the core-count and PCIe lane advantages of the X299 platform. It's a rare product that fills a very specific gap, and its availability now comes mainly from remaining stock or second-hand channels.

Compatibility Guide

  • CPU socket: LGA2066 – compatible with Intel Core i7/i9 X-series (Skylake-X Refresh, Kaby Lake-X).
  • Memory: Dual-channel DDR4 UDIMM (non-ECC) only, up to 128GB (32GB per DIMM).
  • Form factor: Mini ITX (170×170mm) – fits all Mini ITX cases.
  • PCIe: Single PCIe 3.0 x16 slot – no multi-GPU support.
  • Storage: 2× SATA 6Gbps, 1× Ultra M.2 (PCIe 3.0 x4), 1× M.2 (SATA).
  • Power: ATX 24-pin main, plus 8-pin and 4-pin EPS CPU connectors. A PSU with dual EPS outputs is required.
  • Recommended PSU: 750W or higher (850W+ for overclocked builds with high-end GPUs).

Product Info

The ASRock X299E-ITX/ac launched in 2017. Current pricing is around ¥65,702 (approx. $450 USD) via Yahoo Shopping as of September 2026. The chipset is Intel X299, socket LGA2066, and the form factor is Mini ITX. It features 2 DDR4 DIMM slots (max 128GB), one PCIe 3.0 x16 slot, and a combined storage interface of SATA and M.2. It occupies a niche position in the high-end segment: it is the only Mini ITX motherboard for the X299 platform, making it irreplaceable for specific compact builds.

Best Use Cases

  • Compact workstation builders: If you need a high-core-count CPU (e.g., Core i9-10980XE) in a small chassis, this is essentially your only choice. The trade-off is limited expandability, but the raw CPU performance in a Mini ITX package is unmatched.
  • Enthusiasts repurposing older high-end hardware: Pairing this board with a used Core i7-7820X or i9-7900X can deliver competitive single-threaded performance at a relatively low cost. Ideal for budget-conscious builders who want X-class features.
  • Not for: Gamers wanting PCIe 4.0/5.0, users planning dual-GPU setups, or anyone needing DDR5 memory. Also avoid if you require multiple PCIe expansion cards (capture cards, audio interfaces).

Things to Consider

The ASRock X299E-ITX/ac is a highly specialized product. Its biggest limitation is the single PCIe slot – you cannot add a sound card, capture card, or additional NVMe adapter without a riser and external enclosure. The M.2 slots share PCIe lanes with the CPU, so lane distribution matters. Also, the LGA2066 platform is now several generations old; sourcing a new CPU can be difficult, and used market prices vary. The power connector requirement (8+4 pin EPS) may not be supported by all PSUs, so check your power supply's EPS cable count before purchasing. Overclocking headroom is decent but limited by the small PCB and VRM cooling compared to larger X299 boards.

FAQ

Q: Can I use a Core i9-10900X with this motherboard?
A: Yes, it's compatible. However, check the BIOS version – older boards may need an update. Consult ASRock's CPU support list for the exact stepping.
Q: What are the main case fitting concerns?
A: The 8+4 pin EPS connectors are located near the top edge of the board, so ensure your case has enough clearance for the cables. Also, consider CPU cooler height limits typical of Mini ITX cases.
Q: Does this board support PCIe 4.0 graphics cards?
A: The physical slot is PCIe 3.0 only. A PCIe 4.0 GPU will work but run at 3.0 speeds. In most games and applications, the performance difference is negligible.