External vs. Internal SSDs: The Big Picture
An external SSD connects over USB or Thunderbolt outside your PC, while an internal M.2 NVMe SSD plugs directly into the motherboard, and choosing between them means balancing peak speed, portability, upgrade complexity, and how you game, edit, and move large files day to day.
If you want maximum raw speed for a new gaming or content‑creation build, a PCI Express M.2 drive such as the WD Black SN8100 (PCIe 5.0) or SN850X (PCIe 4.0) is still the performance king for internal storage, with each earning a Lab Award for topping their respective benchmark classes. But if you need workstation‑class performance you can move between machines, the LaCie Rugged SSD Pro5 on Thunderbolt 5 stands out as the fastest external SSD tested across a pool of more than 60 drives benchmarked over five years. In short: builders chasing frame times should lean internal; creators juggling multiple systems should eye Thunderbolt 5 storage.
Spec Showdown: Thunderbolt 5 External vs. PCIe M.2 Internal
Before diving into workflows, it helps to line up how a cutting‑edge Thunderbolt 5 external drive compares with the fastest PCIe 4.0 and 5.0 M.2 SSDs on paper, based on interface speeds and how our referenced labs test them.
| Spec / Metric | LaCie Rugged SSD Pro5 (External) | WD Black SN8100 & SN850X (Internal M.2) |
|---|---|---|
| Form factor / connection | External SSD using Thunderbolt 5 interface | Gumstick‑size PCIe 4.0/5.0 M.2 NVMe SSDs for motherboard M.2 slots |
| Peak real‑world sequential throughput | Rated above 6,000MBps read/write over Thunderbolt 5 (about 80Gbps) in current systems | PCIe 4.0 tops out around 7,400MBps read and 7,000MBps write; PCIe 5.0 a little above 14,000MBps for both |
| Benchmark coverage | Crystal DiskMark, PCMark 10 Storage, and Blackmagic Disk Speed Test used to rank fastest external SSD | Benchmarked as secondary data drives in dedicated PCIe 4.0 and 5.0 testbeds, with a formal internal SSD test methodology |
| Gaming‑focused testing | Also measured with a gaming‑centric 3DMark Storage benchmark alongside productivity tests | Included in a suite of internal NVMe benchmarks across more than 100 drives since 2020 |
| Market recognition | Winner of a Lab Award for fastest external SSD after testing 60+ drives over five years | Both SN8100 (PCIe 5.0) and SN850X (PCIe 4.0) earn inaugural internal SSD Lab Awards, now also sold under the Sandisk brand |
External SSD Performance: When Thunderbolt 5 Shines
Thunderbolt 5 storage pushes external SSD performance closer to high‑end internal drives. Recent Thunderbolt 5 SSDs are rated for more than 6,000MBps sequential reads and writes, or about 80Gbps, even though they do not yet reach the 10,000MBps theoretical ceiling because of system bandwidth limits. The LaCie Rugged SSD Pro5 leads this pack, taking a Lab Award after topping a dataset built from more than 60 external drives tested over five years using Crystal DiskMark, PCMark 10 Storage, and Blackmagic Disk Speed Test. One clear takeaway from that testing is that “fast connectivity is king” for external SSD performance, with USB4, Thunderbolt 4, and Thunderbolt 5 drives climbing far above older USB 3.2 options in real‑world throughput.
For workflows, that speed matters most when you stream large contiguous data: 4K/8K editing, raw photo catalogs, or frequent full‑system backups. Sequential tests directly measure these large file transfers and show how Thunderbolt 5 cuts waiting time for archive jobs, video timelines, and project swaps between machines. External drives are also benchmarked with PCMark 10 Storage for everyday file moves and app launches, and with a gaming‑centric 3DMark Storage test for load times. If you want a drive that can shuttle between desktops, laptops, and maybe a studio Mac while still performing like a scratch disk, the Pro5‑class Thunderbolt 5 SSD is the clear pick over an internal upgrade.
Internal NVMe Benchmarks: PCIe 4.0 vs. 5.0 in Real Use
Internal M.2 NVMe SSDs still have a raw‑speed edge because they sit directly on the PCI Express bus. PCIe 4.0 drives now reach about 7,400MBps sequential reads and 7,000MBps writes, while PCIe 5.0 models such as the WD Black SN8100 push a little above 14,000MBps in both directions. Those numbers translate to snappier level loads, quicker large‑game installs, and faster local project opens than even the fastest Thunderbolt 5 external options can usually match. The SN8100 and PCIe 4.0 champion SN850X earned the first internal SSD Lab Awards after standing out in a benchmark pool of more than 100 internal drives tested since 2020.
These M.2 SSDs are tested as secondary data drives in dedicated open‑frame systems that separately target PCIe 4.0 and 5.0, with a published methodology for internal NVMe benchmarks. Beyond peak speeds, newer PCIe 4.0 and 5.0 sticks have improved efficiency through updated NAND designs and DRAM‑less controllers, helping them run cooler and reduce thermal throttling and the need for large heatsinks. For gamers and power users, that means consistent performance during long play sessions or heavy compile jobs. If your priority is the fastest possible in‑box experience with minimal cables and you are comfortable popping open a case, a WD/Sandisk M.2 drive is the smarter choice than an external Thunderbolt unit.
Shared Limits, Use‑Case Trade‑offs, and How to Decide
Both external Thunderbolt 5 drives and high‑end PCIe M.2 SSDs face the same headwind: an ongoing shortage of RAM and flash memory has pushed storage prices up and slowed the release of new products. That shortage, combined with fewer fresh consumer launches, has even slowed wider PCIe 5.0 adoption along with a cooling DIY market. So your decision is less about chasing the “next big thing” and more about fitting today’s proven speed leaders to your actual workloads.
Think in terms of where the drive will live and what it will do most. External Thunderbolt 5 storage excels when you routinely move terabytes between machines or need a single work drive for desktops and laptops, with strong performance across program loading, file transfer, and creative work as reflected in PCMark 10 Storage and Blackmagic sequential metrics. Internal NVMe drives shine when they stay inside one PC and drive game load times and daily responsiveness, backed by structured M.2 SSD testing on dedicated platforms. If you are uncertain, ask yourself whether you value portability or in‑case simplicity more; the answer will usually point you clearly toward one camp.
- Buy the LaCie Rugged SSD Pro5 if you edit large video projects on multiple machines and want Thunderbolt 5 storage you can carry between them.
- Skip the LaCie Rugged SSD Pro5 if your drive will never leave one desktop and you care most about raw in‑case speed per port used.
- Buy the WD Black SN8100 if you own a PCIe 5.0‑ready system and want the fastest internal NVMe benchmarks your motherboard can handle.
- Skip the WD Black SN8100 if your board or laptop is limited to PCIe 4.0 and cannot benefit from its extra bandwidth.
- Buy the WD Black SN850X if you want a proven, award‑winning PCIe 4.0 M.2 SSD for gaming and creation without chasing bleeding‑edge standards.
- Skip the WD Black SN850X if you specifically need external SSD performance that works across several PCs without opening any cases.
