World's Thinnest Portable SSD: Lexar Muse Is Just 3.8mm Thick

An SSD Thin Enough to Double as a Cheese Knife

At IFA in Berlin, Lexar unveiled a portable solid-state drive called the Muse, billing it as the "world's thinnest." At its thickest point, it measures just 3.8mm — and tapers down to a mere 1mm at the outer edges. This nearly blade-like form factor makes it a genuinely unusual entry in the portable storage space. As one reviewer quipped, it's thin enough to "moonlight as a cheese knife."

Achieving this level of thinness wasn't accidental. The Muse uses a custom ultra-thin PCB paired with high-density NAND flash chip stacking to squeeze up to 1TB of storage into a profile that's almost imperceptible — whether it's in your pocket or attached to the back of an iPhone.

Built for iPhone Video Shooting

The reason Muse needed to be this thin comes down to its core use case. The drive is designed to slip inside a wallet-style case on the back of an iPhone Pro or Pro Max, enabling users to record ProRes 4K 120fps video directly onto the drive.

For professional video creators, shooting high-bitrate ProRes footage on an iPhone puts enormous demands on both storage capacity and write speeds — the built-in storage fills up fast. Muse's approach is to make external storage "invisible" by tucking it behind the phone, a considerably cleaner solution than the various bulky external recording rigs on the market. One reviewer highlighted this by comparing it to their own DIY workaround, underscoring how much more elegant Muse's form factor is.

ProRes is Apple's professional video codec, known for its high bitrate and low compression, preserving rich color detail and dynamic range — it's an industry standard in Hollywood post-production. Starting with the iPhone 13 Pro, Apple supported ProRes recording, but the bitrate is enormous: 4K 120fps ProRes footage can consume several gigabytes per minute. This far exceeds what most consumer-grade SSDs can sustain in continuous writes. While Apple's internal storage is fast, it's capacity-limited — a 256GB model can fill up in under an hour at high-bitrate settings. That's exactly why professional creators need external storage, and how to keep that storage from getting in the way of handheld shooting is the engineering problem Muse aims to solve.

Performance: Capable, But Not Class-Leading

On the speed front, Muse offers sequential read speeds up to 1000MB/s and write speeds up to 1050MB/s. For direct recording of ProRes 4K 120fps video, that's "quite impressive" — more than sufficient to handle the real-time write demands of high-bitrate footage.

Of course, compared to desktop-class or flagship portable SSDs optimized for raw performance, these numbers aren't at the top of the charts. But given that Muse prioritizes extreme thinness and portability over high-load workstation duties, the trade-off is reasonable. Its goal is to let you capture high-bitrate video anywhere, anytime — not to win benchmarks in a lab.

The Trade-Off: A Proprietary Pogo Pin Interface

The ultra-thin design does come with a notable compromise. Because the chassis is simply too slim to accommodate a standard USB-C port, Muse uses a proprietary Pogo pin connection to interface with the iPhone or a computer.

This means sacrificing universality. One reviewer noted bluntly that when it comes to exporting files, the proprietary connector "can be a bit of a hassle" — you can't just plug it into any device the way you would with a standard USB-C drive. You're dependent on a dedicated connection structure. For the primary use case of recording video while attached to the back of an iPhone, the Pogo pin approach is actually more elegant; but the moment you step outside that scenario, the interface's limitations become apparent.

Pogo pins are spring-loaded electrical connectors that maintain contact through an internal spring mechanism. They're commonly found in applications that require repeated connections while keeping a low profile — smartwatch charging docks, factory test fixtures, and some tablet keyboard connectors. Their advantage is an extremely flat contact point that requires no slot or latch; just press and it conducts. The trade-off is that the connection relies on physical pressure rather than a locking mechanism like USB-C, so outside a dedicated cradle or case, they can't interface directly with arbitrary devices. Apple's own MagSafe ecosystem uses a similar concept for magnetic charging, but data transfer demands far greater contact stability — which is exactly why Pogo pin solutions have an inherent weakness when it comes to general-purpose connectivity.

A Form Factor Worth Watching

Setting aside the specs, what makes the Lexar Muse genuinely interesting is what it represents: as smartphone photography continues pushing toward professional video, how external storage can integrate into the shooting workflow with minimal physical footprint is becoming a real design challenge.

Muse's answer is extreme thinness and body-hugging integration — at the cost of a proprietary interface and a steeper learning curve. It's not a universal drive for everyone; it's a purpose-built tool for a specific mobile video creation workflow. Whether this "razor-thin" SSD form factor will kick off a new era in portable storage is something only the market and real-world use can ultimately confirm.