USB 3.2 Gen2x2 (20Gbps) - Reality Check¶
Who needs this information?
This page is only relevant if you are planning to buy the Magewell USB Capture HDMI 4K Pro capture card and want to achieve maximum 4K60 4:4:4 capture quality. If you are using a different capture card, you can skip this section.
Critical Finding
USB 3.2 Gen2x2 on laptops is "rare as hell" - Almost no laptops actually support it.
Key Facts¶
| Fact | Details |
|---|---|
| Gen2x2 on laptops | Extremely rare - no manufacturer explicitly advertises it |
| USB4/TB4 = Gen2x2? | No - Gen2x2 fallback is optional, most only fall back to 10Gbps |
| Apple Macs | Explicitly do NOT support Gen2x2 (confirmed by Magewell) |
| Desktop support | Available on motherboards with ASMedia ASM3242 controller |
Laptops - UNVERIFIED Claims¶
These laptops were claimed to have Gen2x2 support, but we could NOT verify this with official manufacturer documentation:
| Laptop | CPU | USB-C Ports (Official Specs) | Gen2x2 Status |
|---|---|---|---|
| Lenovo ThinkBook 16p G6 (AMD) | AMD Ryzen 9 8940HX | USB 3.2 Gen 2 (10Gbps) |  NOT Gen2x2 |
| Lenovo ThinkBook 16p G6 (Intel) | Intel Core Ultra 7/9 | Thunderbolt 4 / USB4 (40Gbps) |  Fallback unconfirmed |
| ASUS Zenbook Pro 16X OLED (UX7602) | Intel i9-12900H / i9-13900H | Thunderbolt 4 (40Gbps) | Fallback unconfirmed |
| MSI Creator Z16P B12U | Intel i9-12900H | Thunderbolt 4 (40Gbps) | Fallback unconfirmed |
| Acer Predator Helios 16 (PH16-71) | Intel i7-13700HX / i9-13900HX | USB4 / Thunderbolt 4 | Fallback unconfirmed |
| Gigabyte AERO 16 OLED | Intel i7-13700H | USB4 / Thunderbolt 4 | Fallback unconfirmed |
| ASUS ROG Flow Z13 (2025) | Intel / AMD (varies) | USB4 (40Gbps) | Fallback unconfirmed |
| Dell Inspiron 15 5515 | AMD Ryzen 5 5500U | USB 3.2 Gen 2 (claimed Gen2x2) | Discontinued |
Why 'Fallback unconfirmed'?
USB4/Thunderbolt 4 CAN support Gen2x2 fallback, but it's optional in the spec. Most implementations only fall back to 10Gbps for USB 3.x devices. Without explicit manufacturer confirmation or real-world testing, we cannot verify 20Gbps support.
Verified Gen2x2 Support - Desktops Only¶
Native USB 3.2 Gen2x2 is primarily available on desktop motherboards and PCIe add-in cards:
Motherboards with Gen2x2¶
| Platform | Controller Chip | Status |
|---|---|---|
| AMD TRX40 motherboards (2019+) | ASMedia ASM3242 |  Verified |
| Intel Z490 and newer motherboards | ASMedia ASM3242 | Verified |
| High-end AMD X570/X670 boards | ASMedia ASM3242 | Verified |
PCIe Add-in Cards¶
| Card | Controller | Status |
|---|---|---|
| ASUS USB4 PCIe Gen4 Card | ASMedia | Verified |
| Generic ASM3242-based PCIe cards | ASMedia ASM3242 | Verified |
Key Indicator
If a motherboard or card uses the ASMedia ASM3242 controller, it will support USB 3.2 Gen2x2 at 20Gbps.
Magewell USB Capture HDMI 4K Pro¶
What capture quality you get depends on your USB speed:
| USB Speed | Capture Quality |
|---|---|
| 20Gbps (Gen2x2) | 4K60 4:4:4 (full quality) |
| 10Gbps (Gen2) | 4K60 4:2:0 or 4K30 4:4:4 |
| 5Gbps (Gen1) | 4K30 4:2:0 or 1080p60 |
Magewell's Statement on Macs
From Magewell official documentation:
"A 20Gbps USB 3.2 Gen 2x2 interface is required for maximum performance but is not available on Mac systems. While recent Mac systems include a Thunderbolt 4 port capable of 40Gbps, these ports are not backwards-compatible to USB 3.2 Gen 2x2 at 20Gbps."
How to Verify Gen2x2 Support Before Purchase¶
- Look for explicit specs - "USB 3.2 Gen2x2" or "20Gbps USB" in official documentation
- Check for ASM3242 controller - In spec sheets or teardowns
- Contact manufacturer directly - Ask: "Does this USB port support USB 3.2 Gen2x2 at 20Gbps?"
- Search forums - Look for real user tests with Magewell or Gen2x2 SSDs on that specific model
Sources¶
Last updated: January 24, 2026