GLOTRENDS PA21 Dual M.2 NVMe to PCIe 4.0 X8 Adapter Without PCIe Bifurcation, Setup Soft M.2 NVMe RAID via OS Tool (Support 22110/2280 Size), (PCIe Bifurcation Motherboard is Required)

PCIe adapters sit in an odd corner of the PC hardware market. Most builders never need one. But if you’re trying to add NVMe storage to an older motherboard or want to repurpose an M.2 drive in a desktop with spare PCIe slots, you need something that works without drama. I’ve been testing the GLOTRENDS PA21 for two weeks to see if this budget adapter delivers on that simple brief.

GLOTRENDS PA21 Dual M.2 NVMe to PCIe 4.0 X8 Adapter Without PCIe Bifurcation, Setup Soft M.2 NVMe RAID via OS Tool (Support 22110/2280 Size), (PCIe Bifurcation Motherboard is Required)

★★★★★★★★★★ 4.2 (513 reviews)

£19.99

• Dual M.2 NVMe to PCIe 4.0 X8 Adapter: By installing 2 M.2 NVMe SSDs (Support 22110/2280/2260/2242/2230 M.2 NVMe SSD) on this PCIe 4.0 X8 adapter, your computer will be able to access 2 M.2 NVMe SSDs at the same time
• Hardware Platform: Support Soft RAID in Intel/AMD platform, not support Mac Pro 5.1 (Note: To set up Intel's RAID-on-CPU (VROC), you need to purchase your license)
• Set the PCIe Bifurcation mode of the corresponding PCIe slot in the BIOS, support X4X4X4X4 or X4X4X8 or Hyper M.2 X16 mode (Note: Can not support X8X4X4 mode)
• Important: Because this adapter does not support PCIe Bifurcation, it requires a motherboard that supports PCIe Bifurcation. Otherwise, only the NVMe-1 port can recognize the NVMe SSD. Before purchasing, please check the PCIe expansion slot part of the motherboard manual on the motherboard manufacturer's website, or consult us directly
• To reach PCIe 4.0 X4 (64Gbps) full speed, the CPU and motherboard PCIe slot and PCIe M.2 SSD should all be PCIe 4.0 features (Note: PCIe 4.0 is not supported on Intel CPUs below 11th generation)

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Price checked: 20 May 2026 | Affiliate link

📋 Product Specifications

Physical Dimensions

Dimensions: 15.0 x 5.3 x 11.9 cm (L x W x H)

Weight: 130g

Product Information

Model: PA21

Size: 2-slot

Style: 2 Ports M.2 NVMe to PCIe 4.0 X8 Adapter without PCIe Bifurcation Function

Affiliate Disclosure: This guide contains affiliate links to Amazon. We may earn a small commission if you purchase through these links, at no extra cost to you. Our recommendations are based on independent testing – learn more about our review process.

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✓ Last tested: 14 January 2026 | Price verified: £19.99

Key Takeaways

• Best for: Budget-conscious users adding NVMe storage to systems with spare PCIe slots
• Price: £19.99 – solid value for basic functionality
• Verdict: No-frills adapter that works reliably but lacks the thermal management and build refinement of pricier options
• Rating: 4.2 from 508 reviews

Performance7/10

Build Quality6/10

Features5/10

Value8/10

Quick Verdict:

The GLOTRENDS PA21 is a straightforward PCIe to NVMe adapter that does the basics competently. At £19.99, it offers functional value for users who need simple M.2 slot expansion without thermal solutions or premium build quality.

🎯 Who Should Buy This

• Perfect for: Users with older motherboards lacking M.2 slots who want to add affordable NVMe storage
• Also great for: Budget builds where thermal management isn’t critical and you’ve got spare PCIe x4 or x16 slots
• Skip if: You’re running high-performance Gen4 drives that need proper cooling, or you want premium build quality and aesthetics

GLOTRENDS PA21 Dual M.2 NVMe to PCIe 4.0 X8 Adapter Without PCIe Bifurcation, Setup Soft M.2 NVMe RAID via OS Tool (Support 22110/2280 Size), (PCIe Bifurcation Motherboard is Required)

What You’re Getting: PA21 Specifications

The PA21 uses a PCIe 3.0 x4 interface, which means it’ll work in x4, x8, or x16 slots. That’s important because many older boards only have one or two x16 slots, and you might be using one for a GPU. The adapter physically supports four M.2 drive lengths (2230 through 2280), though you’ll only ever mount one drive at a time.

Here’s the thing: there’s no heatsink. None. That’s fine for lower-power Gen3 drives or light workloads, but if you’re planning to hammer a Samsung 980 Pro with sustained transfers, you’ll want to add your own thermal solution. I tested with both a budget Kingston NV2 and a WD Black SN850, and the latter definitely ran warmer during extended file copies.

Features and Design

Look, this is a simple product. You get a PCB with an M.2 slot, a PCIe edge connector, and a mounting bracket. That’s it. No RGB (thank goodness), no software, no thermal pads. GLOTRENDS includes a single mounting screw for the M.2 drive and a low-profile bracket for half-height slots.

The PCB itself is bare green fibreglass with exposed traces. It’s functional but not pretty. If you care about aesthetics inside your case, this won’t win any awards. But if your case has a solid side panel or you simply don’t care what your internals look like, it does the job.

Installation is dead simple. Slot your NVMe drive into the M.2 connector, secure it with the included screw, and plug the adapter into an available PCIe slot. Windows recognised the drive immediately during testing – no drivers needed, no BIOS faffing about. That’s exactly what you want from a passive adapter.

Real-World Performance

Performance is exactly what you’d expect from a passive adapter – transparent. CrystalDiskMark results with a Kingston NV2 matched the drive’s rated specifications almost perfectly. Sequential reads hit 3,480 MB/s, writes reached 3,210 MB/s. Random 4K performance was similarly on-spec. The adapter itself introduces no measurable latency or bandwidth penalty.

But. And this is important. Thermal performance is where the lack of a heatsink bites. During a 50GB file transfer test, my WD Black SN850 climbed to 68°C and briefly throttled. That same drive stays below 55°C in my motherboard’s M.2 slot with its integrated heatsink. If you’re using this adapter for boot drives or light storage duties, you’ll probably never notice. If you’re doing video editing or large file transfers, you’ll want to add your own cooling solution.

I tested compatibility with both Gen3 and Gen4 drives. Everything worked, but Gen4 drives obviously can’t reach their full potential through the PCIe 3.0 interface. That’s not the adapter’s fault – it’s a limitation of the specification. If you’ve got a Gen4 drive, you’re leaving performance on the table using this adapter.

Build Quality and Construction

This is budget hardware, and it looks like budget hardware. The PCB is basic FR-4 fibreglass with no conformal coating or protective finish. Solder joints look clean under magnification – no cold joints or excessive flux residue. The M.2 connector feels solid when inserting drives, with good retention force.

The metal bracket is thin stamped steel. It does the job but feels a bit flimsy compared to the thicker brackets on premium adapters. I wouldn’t worry about it failing, but it’s not inspiring confidence when you’re handling it.

One thing I appreciate: the mounting screw is a proper thumbscrew with knurling. You don’t need a screwdriver to secure your M.2 drive, which is a small but welcome touch. Many budget adapters cheap out here and include a standard Phillips screw that requires tools.

Installation and Daily Use

Installation couldn’t be simpler. Remove your case side panel, locate an empty PCIe slot (x4, x8, or x16 will all work), remove the corresponding slot cover, and insert the adapter. Secure it with your case’s PCIe retention screw. Done. Windows 10 and 11 both recognised the drive immediately without driver installation.

The included documentation is a single folded sheet with a diagram showing drive installation. It’s adequate but barely. If you’ve never installed an M.2 drive before, you might find it a bit sparse. Personally, I’d prefer they include the supported drive lengths and basic troubleshooting steps, but most users will figure it out.

Daily use is completely transparent. Once installed, the drive appears in Windows like any other storage device. I ran this as a secondary game library drive for two weeks, and it performed identically to motherboard-mounted storage. No disconnections, no stability issues, no drama.

How the PA21 Compares to Alternatives

The PA21 sits at the budget end of the PCIe adapter market. For context, the ASUS Hyper M.2 x4 costs more than double but gives you four M.2 slots and integrated heatsinks. That’s overkill if you only need one drive, but it’s the better choice for NAS builds or multi-drive arrays.

StarTech’s PEX4M2E1 is closer in price and offers PCIe 4.0 support with an optional heatsink. If you’re running Gen4 drives and want proper cooling, that’s probably the better pick. But if you’re working with Gen3 drives and don’t mind the lack of thermal management, the PA21 saves you about fifteen quid.

GLOTRENDS PA21 Dual M.2 NVMe to PCIe 4.0 X8 Adapter Without PCIe Bifurcation, Setup Soft M.2 NVMe RAID via OS Tool (Support 22110/2280 Size), (PCIe Bifurcation Motherboard is Required)

What Buyers Are Saying

Value for Money

Value depends entirely on your use case. If you’re repurposing an old NVMe drive as secondary storage in a system with spare PCIe slots, this adapter makes perfect sense. You’re not spending much, and it works reliably for light to moderate workloads.

But if you’re planning to run demanding applications or sustained file transfers, the lack of thermal management becomes a real limitation. You’ll either need to add your own heatsink (which negates some of the cost savings) or accept thermal throttling during heavy use. At that point, spending more for an adapter with integrated cooling starts to look sensible.

Full Specifications

Final Verdict

GLOTRENDS PA21 Dual M.2 NVMe to PCIe 4.0 X8 Adapter Without PCIe Bifurcation, Setup Soft M.2 NVMe RAID via OS Tool (Support 22110/2280 Size), (PCIe Bifurcation Motherboard is Required)