External USB SSDs ranked by price per terabyte, with the one thing the spec sheets bury: what the USB rating actually delivers. 9 portable drives compared, up to 2,100 MB/s. Updated July 31, 2026.
Cheapest portable SSD: Crucial X10 4TB Portable — $101.94/TB ($407.74 total)
These are USB, not SATA or PCIe: real-world speed is set by the USB standard, from ~1,000 MB/s (USB 3.2 Gen 2) to ~2,000 MB/s (Gen 2x2) and ~3,000+ MB/s (USB4 / Thunderbolt)
Check your port: a fast drive on a slow port runs at the port's speed
Last checked July 31, 2026. Prices come from Amazon US and are refreshed every day; $/TB is the listing price divided by raw capacity. Full methodology.
| $/TB | $/GB | Price | Lowest seen | Capacity | Interface | Gen | Read | Write | NAND | Warranty | Cond. | Product |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| $101.94BEST | $0.102 | $407.74 | LOWEST YET | 4 TB | External | USB | 2,100 MB/s | 2,000 MB/s | — | 5 yr | New | Crucial X10 4TB Portable |
| $107.33 | $0.107 | $643.99 | LOWEST YET | 6 TB | External | USB | 2,100 MB/s | 2,000 MB/s | — | 5 yr | New | Crucial X10 6TB Portable |
| $124.69 | $0.125 | $498.74 | LOWEST YET | 4 TB | External | USB | 2,100 MB/s | 2,000 MB/s | — | 5 yr | New | Crucial X10 Pro 4TB Portable |
| $151.94 | $0.152 | $303.88 | $289.57 | 2 TB | External | USB | 1,050 MB/s | 1,000 MB/s | — | 5 yr | New | SanDisk Extreme 2TB Portable |
| $161.93 | $0.162 | $323.86 | $321.55 | 2 TB | External | USB | 2,100 MB/s | 2,000 MB/s | — | 5 yr | New | Crucial X10 Pro 2TB Portable |
| $195.00 | $0.195 | $389.99 | $139.99 | 2 TB | External | USB | 1,050 MB/s | 1,000 MB/s | — | 5 yr | New | WD My Passport SSD 2TB |
| $209.53 | $0.210 | $419.07 | $408.98 | 2 TB | External | USB | 2,000 MB/s | 2,000 MB/s | — | 3 yr | New | Samsung T9 2TB Portable |
| $214.00 | $0.214 | $214.00 | $193.78 | 1 TB | External | USB | 1,050 MB/s | 1,000 MB/s | — | 3 yr | New | Samsung T7 1TB Portable |
| $228.61 | $0.229 | $914.44 | $299.99 | 4 TB | External | USB | 2,000 MB/s | 2,000 MB/s | — | 3 yr | New | Samsung T9 4TB Portable |
This is where most portable-SSD guides mislead you, and where a listing can look faster than it will ever run on your machine. A portable SSD's speed is set by the slowest link in the chain: the drive, the USB standard it uses, and the port you plug it into. The drive is rarely the bottleneck — the USB standard is.
USB 3.2 Gen 2 (10 Gbps) tops out around 1,050 MB/s. This is the most common portable-SSD class — the Samsung T7, WD My Passport and SanDisk Extreme all live here. USB 3.2 Gen 2x2 (20 Gbps) reaches about 2,000 MB/s but needs a matching 2x2 port, which is uncommon. USB4 / Thunderbolt can exceed 3,000 MB/s. A drive rated for 2,000 MB/s plugged into an ordinary 10 Gbps port will deliver 1,050 — the port wins.
Console expansion & backups: any 10 Gbps drive is plenty. Games and file backups don't saturate 1,050 MB/s, so paying for a faster class buys nothing here — put the money into capacity.
Photo and video editing off the drive: this is where a 2,000 MB/s Gen 2x2 or a USB4 drive earns its premium, but only if your machine has the matching port. Confirm the port before paying for the speed.
Rugged / travel: look for an IP-rated body (the SanDisk Extreme and similar are IP55/IP65). A drop- and water-resistant shell matters more than a few hundred MB/s for a drive that lives in a bag.
A portable SSD is an internal drive in a USB enclosure, and you pay for that enclosure. Per terabyte, portables run higher than a bare internal NVMe drive. If you only need portability occasionally, a cheap internal NVMe plus a $20–30 USB enclosure can beat a pre-built portable on price — and lets you reuse the drive later.
Where pre-built portables win is convenience, a rugged sealed body, and warranty coverage of the whole unit. For a drive you'll toss in a bag daily, that's usually worth it; for a drive that mostly sits on a desk, the enclosure route saves money.
Some marketplace listings label a portable SSD's interface as SATA. Ignore that field. Externally these drives connect over USB, and the ones reading past 560 MB/s cannot be SATA — that's above the SATA ceiling. What matters is the USB standard (10 Gbps, 20 Gbps, USB4) and your port, which the table above reflects.