# Motherboards, CPU trays, switch trays

Part ID: 4.04 · Layer 4 (Servers, racks & integration)

The non-GPU trays in a rack — CPU-only compute trays, host motherboards and the switch trays carrying scale-up switch silicon — built by the same board makers as the GPU trays.

This part covers the trays that round out a rack-scale system alongside the GPU baseboard (4.03): CPU-only compute trays for control and orchestration nodes, conventional server motherboards, and switch trays that carry the scale-up switch silicon (3.01) linking GPU trays together. The same ODM tier that builds GPU baseboards builds these, joined by motherboard specialists who don't necessarily compete for GPU-tray business. AI racks need more of this category than a conventional data center rack: a rack-scale cabinet carries dedicated switch trays purely to fan out the scale-up fabric, a tray type that barely existed before rack-scale GPU systems. For investors, this is a lower-margin, higher-volume counterpart to the GPU baseboard — less differentiated, more competitive — so the interesting question is less "who wins" and more whether a builder's exposure here dilutes or complements its GPU-tray economics.

**AI delta:** Rack-scale GPU systems require dedicated switch trays purely to fan out the scale-up fabric between GPU trays, a tray category that has little equivalent in conventional servers.

## Companies

| Company | Role | Confidence | Ownership | Ticker | Note |
|---|---|---|---|---|---|
| ASRock Rack | manufacturer | inferred | public | 3515.TW |  |
| ASUS | manufacturer | inferred | public | 2357.TW |  |
| Gigabyte | manufacturer | inferred | public | 2376.TW | the same ODMs plus |
| MiTAC (Tyan) | manufacturer | inferred | public | 3706.TW |  |
| MSI | manufacturer | inferred | public | 2377.TW |  |

Confidence tags: disclosed = company/filing statement; reported = trade press or partner list; inferred = taxonomy lead.