Can a Portable SSD Run AAA Games? We Tested Cyberpunk 2077 Over USB-C
Modern laptops ship with fast internal storage — but rarely enough of it. One AAA title can swallow 70–100 GB, and if you only have a 512 GB drive, you're choosing between Cyberpunk and your work files. The obvious question: what if you just installed the game on a portable SSD and played directly from USB?
We did exactly that. We installed Cyberpunk 2077 on a 20 Gbps portable SSD — the OSCOO MD100 — connected it to a laptop over USB-C, and ran the built-in benchmark. The result: an average of 59.29 FPS at 2560×1600 with Ray Tracing enabled, a min-to-max spread of just 8.85 FPS, and no stuttering whatsoever. Loading screens lasted roughly one to two seconds. In practical terms, the game was indistinguishable from running off internal storage.
Here's the full breakdown of what we tested, what we found, and where external SSD gaming does — and doesn't — make sense.
Why Would Anyone Game From an External SSD?
The scenario is more common than it sounds. A student with a 512 GB laptop and three AAA games they want to keep installed. A creative professional whose internal drive is already full of project files. Someone who games on both a desktop and a laptop and doesn't want to re-download 100 GB every time they switch machines. Or a Steam Deck owner who wants a bigger library than the internal storage allows.
The internet is full of forum threads asking whether this actually works. Most answers are speculative: "it should work in theory," "probably fine for older games," "USB is too slow for modern titles." Very few provide real benchmark data from a specific game on a specific device. That's what this test is — a concrete answer with numbers attached.
If you're also considering an internal NVMe upgrade for a handheld or laptop, our Steam Deck SSD upgrade guide covers that side of the equation.
What We Tested and How
We installed the full version of Cyberpunk 2077 (v2.31) on an OSCOO MD100 portable SSD and connected it to a laptop via USB-C. The game was launched and played entirely from the external drive — no internal SSD was used for game storage, caching, or shader compilation.
Test hardware:
| Component | Specification |
| External SSD | OSCOO MD100, USB 3.2 Gen2x2, 20 Gbps |
| GPU | NVIDIA GeForce RTX 5060 Laptop |
| CPU | Intel Core Ultra 9 275HX |
| RAM | 32 GB |
| OS | Windows 11 |
| Game version | Cyberpunk 2077 v2.31 |
| GPU driver | v592.01 |
Graphics settings:
| Setting | Value |
| Resolution | 2560×1600, Fullscreen |
| Preset | Ray Tracing: Low |
| Texture quality | High |
| DLSS | Auto (Transformer Model) |
| Ray Tracing | On (Local Shadows) |
| Frame Generation | Off |
We deliberately kept Frame Generation off. Enabling it would inflate the frame count and mask any micro-stuttering caused by storage latency — defeating the purpose of the test.
How Did It Actually Perform? FPS Benchmark Results
The built-in benchmark gave us these numbers:
| Metric | Result |
| Average FPS | 59.29 |
| Minimum FPS | 54.46 |
| Maximum FPS | 63.31 |
| FPS spread | ~8.85 |
The spread between minimum and maximum is the most telling figure here. An 8.85 FPS range means the frame rate held remarkably steady throughout the benchmark sequence, which includes driving, combat, crowd scenes, and environmental transitions — exactly the scenarios where a slow storage device would cause frame drops or hitches.
For context, a spread under 10 FPS is considered very stable in Cyberpunk 2077's benchmark. The game is running at the GPU's natural limit, and the external SSD is feeding data fast enough that storage never becomes the bottleneck.
What About Loading Times and Asset Streaming?
This is where most skeptics expect external SSDs to fall short. Two specific concerns come up repeatedly: long loading screens and texture pop-in during gameplay.
Loading times: Scene transitions and fast travel loading screens lasted approximately one to two seconds. This is fast enough that you barely register them — comparable to what you'd expect from an internal NVMe SSD at this performance tier. We did not observe any prolonged loading sequences that would suggest the USB connection was creating a bottleneck.
Texture streaming in open world: We spent extended time driving through Night City at high speed — the most demanding scenario for asset streaming, as the game needs to load textures, geometry, and lighting data for new areas in real time. We observed zero texture pop-in, no LOD (level-of-detail) transition artifacts, and no micro-stuttering during rapid movement. The city loaded seamlessly around the vehicle at all times.
Thermal performance: After an extended gaming session, the MD100's surface temperature reached approximately 50–60°C. This is noticeably warm to the touch — warmer than typical idle or file-transfer use — but within the normal operating range for a portable SSD under sustained heavy read load. Most NAND flash operates safely up to 70°C before thermal throttling begins. We did not observe any performance degradation over the course of our testing, which suggests the drive maintained stable speeds throughout without hitting thermal limits.
Worth noting: if you plan to game from an external SSD regularly, avoid stacking it under objects or placing it in enclosed spaces. Airflow matters. The MD100's flat aluminum body acts as a passive heatsink, which helps — but physics still applies.
When Does an External SSD Fall Short for Gaming?
Being honest about the limitations is just as important as reporting the results. External SSD gaming works well in our test, but it's not a universal replacement for internal storage.
Bandwidth ceiling. USB 3.2 Gen2x2 provides up to 20 Gbps (roughly 2,000 MB/s) of theoretical bandwidth. A direct PCIe Gen3 NVMe connection delivers 32 Gbps, and Gen4 doubles that again. For current-generation games like Cyberpunk 2077, 20 Gbps is clearly sufficient — but future titles with larger texture packs and more aggressive streaming engines may push closer to this limit.
DirectStorage. Microsoft's DirectStorage API allows games to load compressed assets directly from an NVMe SSD into GPU memory, bypassing the CPU entirely. This technology only works with internal NVMe drives — external USB-connected drives cannot benefit from it. As more games adopt DirectStorage, the performance gap between internal and external storage may widen for those specific titles.
Competitive multiplayer. In single-player or co-op games, a one- or two-second loading difference is invisible. In competitive multiplayer, where loading into a match faster can matter, the slight latency overhead of USB may be noticeable — though this is game-dependent and unlikely to be a deciding factor in most scenarios.
The honest framing: External SSD gaming is not a replacement for internal storage. It's a supplement — a way to expand your usable game library without upgrading your laptop's internal drive. For single-player and story-driven games, it works remarkably well.
What Should You Look For in an External SSD for Gaming?
Not all external SSDs are created equal for gaming. The key variable is interface bandwidth.
USB 3.0 (5 Gbps): Roughly 500 MB/s in practice. Functional for older or less demanding games, but will cause noticeable loading delays and potential stuttering in modern AAA titles. Not recommended for this use case.
USB 3.2 Gen2 (10 Gbps): Around 1,000 MB/s. A meaningful improvement — playable for most games, though the headroom is tight for titles with aggressive streaming.
USB 3.2 Gen2x2 (20 Gbps): Up to 2,000 MB/s. This is the practical threshold for comfortable AAA gaming from an external drive. Our test used a drive at this tier, and it performed with no perceptible compromise.
USB4 / Thunderbolt 4 (40 Gbps): The most headroom, approaching internal NVMe speeds. Overkill for current games, but the most future-proof option.
Beyond raw bandwidth, two other factors matter. First, sustained read performance — cheap drives that use QLC NAND without DRAM cache may hit high peak speeds but slow down under sustained load, which is exactly what gaming demands. Second, the physical connection: plug the drive directly into a USB-C port on your laptop. Running through a hub or dock can introduce bandwidth sharing and latency that defeats the purpose.
The 20 Gbps tier is where the cost-to-performance ratio makes the most sense for gaming today. That's the tier we tested, and it's the tier we'd recommend as the practical floor.
The Verdict: Is External SSD Gaming Practical?
Yes — with the right drive. A 20 Gbps portable SSD handled Cyberpunk 2077 at 2560×1600 with Ray Tracing at a steady 59 FPS, one-to-two-second load times, no texture pop-in, and no stuttering. The game was functionally identical to running from internal storage.
It won't replace your internal NVMe for every use case. DirectStorage-enabled titles, competitive multiplayer, and future games with heavier streaming demands may still favor a direct PCIe connection. But for expanding your game library, sharing games between machines, or keeping your laptop's internal drive free for work — external SSD gaming is not a compromise. It's a genuinely viable option.
And it will only get better. USB4 adoption is accelerating, game engines are becoming more efficient with storage I/O, and portable SSD speeds continue to climb. The gap between internal and external is narrowing — and for most players, it's already narrow enough not to matter.
The test in this article was performed using the OSCOO MD100, a 20 Gbps portable SSD with USB 3.2 Gen2x2. Full test footage is available in our video.
