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OWC Envoy Pro FX 4TB vs SSK PM510 USB4 1TB — Which External SSD Is Faster & Better Value?

Compare OWC Envoy Pro FX 4TB and SSK PM510 USB4 1TB side by side. Both are 4TB Thunderbolt 3 external SSDs, but they differ in speed, design, and value. Here's how they stack up.

Our Pick

OWC

OWC Envoy Pro FX 4TB

8.9/10

4TB of Thunderbolt 3 storage in an aluminum unibody barely larger than the 1TB. The Envoy Pro FX 4TB is a niche-of-one — buyers typically pay the premium for video editing workflows where 4000 MB/s sustained links plus 4TB of room actually matter.

Thunderbolt 3 + 4TB

Aluminum unibody

2800 sustained writes

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SSK

SSK PM510 USB4 1TB

8.6/10

AUSB4 portable at enthusiast-grade specs — 3200 MB/s read over USB4 / Thunderbolt 4 hosts. The PM510 is one of the more affordable USB4 portables, an entry point for video editors who need Thunderbolt-class speeds but don't want to pay LaCie or OWC premium.

USB4 3200 MB/s

Thunderbolt 4 compatible

Aluminum body

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Spec Comparison

Spec

OWC Envoy Pro FX 4TB

SSK PM510 USB4 1TB

Read Speed

2.8 GB/s

3.2 GB/s ✓

Write Speed

2.8 GB/s

Capacity

4 TB ✓

1 TB

Interface

Thunderbolt 3

USB4

Endurance (TBW)

2,400 TB ✓

600 TB

Warranty

3 Years

Score

8.9/10 ✓

8.6/10

Total Wins

3 wins

1 win

Frequently Asked Questions

Which is better, OWC Envoy Pro FX 4TB or SSK PM510 USB4 1TB?

The OWC Envoy Pro FX 4TB scores 8.9/10 compared to 8.6/10 for the SSK PM510 USB4 1TB. Our expert analysis favors the OWC Envoy Pro FX 4TB for its superior value.

What's the difference between OWC Envoy Pro FX 4TB and SSK PM510 USB4 1TB?

The key differences: The OWC Envoy Pro FX 4TB offers 2,800 MB/s reads vs 3,200 MB/s for the SSK PM510 USB4 1TB. Capacity options differ: OWC Envoy Pro FX 4TB is 4TB while SSK PM510 USB4 1TB is 1TB. The OWC Envoy Pro FX 4TB uses Thunderbolt 3 while the SSK PM510 USB4 1TB uses USB4.

Which is faster, OWC Envoy Pro FX 4TB or SSK PM510 USB4 1TB?

The SSK PM510 USB4 1TB is faster with 3,200 MB/s read speeds compared to 2,800 MB/s for the OWC Envoy Pro FX 4TB. That's a 14% speed advantage.

Which has better value, OWC Envoy Pro FX 4TB or SSK PM510 USB4 1TB?

The OWC Envoy Pro FX 4TB scores higher (8.9 vs 8.6/10), indicating better overall value in our evaluation. Check both models on the retailer's site for the latest details.

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