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OWC Mercury Helios 3 vs Sonnet eGFX Breakaway Box 550: Comparison
OWC Mercury Helios 3 vs Sonnet eGFX Breakaway Box 550 psu wattage compared
The gap that matters here is psu wattage: OWC Mercury Helios 3 400 W against Sonnet eGFX Breakaway Box 550 550 W, which puts Sonnet eGFX Breakaway Box 550 27% ahead.
OWC Mercury Helios 3 vs Sonnet eGFX Breakaway Box 550: which one fits your build
Buy the OWC Mercury Helios 3 for simple, no-frills dual-slot GPU builds under 400W, though it is not the pick for cards that need more than 290mm of clearance and Windows users wanting extra I/O built into the box. It is equally the pick for Mac users who find a used unit cheap and just need a bare Thunderbolt 3 enclosure. It is not the one for anyone buying new, since the Mercury Helios FX replaced it with more PSU headroom. The Sonnet eGFX Breakaway Box 550 is the one to take for budget builds running GTX 10-series or RTX 20-series double-wide cards and buyers who find it discounted versus the newer 650, though it is the wrong buy for RTX 30-series or newer cards that want more PSU headroom and builds needing more than 300mm of card clearance. It also earns its place with Mac users wanting Sonnet's certified eGFX driver support on Thunderbolt 3. It is the wrong buy for anyone who can spend a little more for the Breakaway Box 650's extra 100W.
Which is cheaper, OWC Mercury Helios 3 or Sonnet eGFX Breakaway Box 550?
At the last price check the OWC Mercury Helios 3 was $299 and the Sonnet eGFX Breakaway Box 550 $399, a 33% premium.
Frequently asked questions
Do the OWC Mercury Helios 3 and Sonnet eGFX Breakaway Box 550 differ on max gpu length?
Yes. Max GPU Length reads 290 mm on the OWC Mercury Helios 3 versus 300 mm on the Sonnet eGFX Breakaway Box 550.
Is the Cooling Type the same on the OWC Mercury Helios 3 and Sonnet eGFX Breakaway Box 550?
It is. Both are listed at Active Fan, so it is not a reason to pick one over the other.
Specs and benchmarks
Brand
- OWC Mercury Helios 3
- OWC
- Sonnet eGFX Breakaway Box 550
- Sonnet
Connection Standard
- OWC Mercury Helios 3
- Thunderbolt 3
- Sonnet eGFX Breakaway Box 550
- Thunderbolt 3
Model Number
- OWC Mercury Helios 3
- Mercury Helios 3
- Sonnet eGFX Breakaway Box 550
- eGFX Breakaway Box 550
Extra Ports
- OWC Mercury Helios 3
- None onboard beyond the GPU's own outputs
- Sonnet eGFX Breakaway Box 550
- None onboard beyond the GPU's own outputs
PSU Wattage
- OWC Mercury Helios 3
- 400 W-27%
- Sonnet eGFX Breakaway Box 550
- 550 WBest
Host Power Delivery
- OWC Mercury Helios 3
- 85 W-2%
- Sonnet eGFX Breakaway Box 550
- 87 WBest
Max GPU Length
- OWC Mercury Helios 3
- 290 mm-3%
- Sonnet eGFX Breakaway Box 550
- 300 mmBest
Cooling Type
- OWC Mercury Helios 3
- Active Fan
- Sonnet eGFX Breakaway Box 550
- Active Fan
GPU Compatibility
- OWC Mercury Helios 3
- GTX 10-series through RTX 20-series, dual-slot cards
- Sonnet eGFX Breakaway Box 550
- GTX 10-series through RTX 20-series and equivalent AMD cards, double-wide
Price
- OWC Mercury Helios 3
- Launched around $299 (2018)
- Sonnet eGFX Breakaway Box 550
- Launched around $399 (2017)
Which one should you pick?
Choose OWC Mercury Helios 3 if you already have it on hand or find it at a lower price.
Choose Sonnet eGFX Breakaway Box 550 if you want the higher PSU wattage (550 W vs 400 W), the higher host power delivery (87 W vs 85 W) and the higher max GPU length (300 mm vs 290 mm).
Price comparison
| Retailer | OWC Mercury Helios 3 | Sonnet eGFX Breakaway Box 550 |
|---|---|---|
| Consumercarts listing | $299.00 View on Consumercarts listing | |
| Amazon | $399.00 View on Amazon |
Disclaimer: The price and specification of the given product may differ from the actual product. Please confirm on the retailer's website before buying.
Verdict
OWC Mercury Helios 3
6 / 10 Expert Rating
Solid basic Mac eGPU box, superseded by the Helios FX which OWC still actively sells.
Sonnet eGFX Breakaway Box 550
6 / 10 Expert Rating
A solid early Sonnet box, but the 650 offers more headroom for little extra cost.
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