LaCie 5big 20TB review

This five-disk RAID array is big on size, weight, capacity, price and speed

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  • Good to excellent speeds
  • Thunderbolt cable is included
  • Easily replaceable disks


  • Only supports two RAID modes

The Lacie 5big drive marries five hard disks in a 20TB volume which, thanks to the capabilities of Thunderbolt, work together at wildly fast speeds.

In tests with very small files, the drive performs about as well as Western Digital's two-disk, 10,000rpm Velociraptor Duo. With larger data, the 5big streaks ahead to peaks of 777.7MB/second and 634.9MB/ second in sequential read and write tests. The first figure is near LaCie's quoted 785MB/second, although the second is further below the expected 695MB/second.

Hard disk performances fluctuate, but the 5big's average read and write speeds of 569.1MB/second and 490.1MB/second remain respectable.

In the tougher random read and write tests, we observed average read and write speeds of 367.8MB/second and 348.9MB/second, respectively. These are within 20MB/second of the peak in these tests, meaning the 5big is more consistent in difficult conditions, and still acceptably fast.

The drive uses OS X's software RAID technology, which limits it to basic striped and mirrored configurations. The latter isn't much use unless you want 4TB's worth of data to be stored five times.

Look for a drive with a hardware-based RAID controller and more exotic RAID types if you need a better blend of speed, capacity and protection against disk failure.


The LaCie 5big offers incredible top speeds and good ones on average, but the price restricts it to pro-level video work.

Tech Specs

Product TypeDAS Array
Number of Total Expansion Bays5
Number of 3.5" Bays5
Total Hard Drive Capacity Installed20 TB
Number of Hard Drives Supported5
Number of Hard Drives Installed5
Brand NameLaCie
Form FactorDesktop
RAID Levels1, JBOD
Host InterfaceThunderbolt
Green CompliantYes
Green Compliance Certificate/AuthorityWEEE
Total Hard Drive Capacity Supported20 TB
Height218.4 mm
Width172.7 mm
Depth195.6 mm
Product Name5big DAS Array
Product Line5big
Manufacturer Part Number9000398EK
Manufacturer Website Address
Marketing Information

With 785MB/s*, immense five-disk capacity, and LaCie proven reliability, the 5big Thunderbolt Series is the perfect complement to a Thunderbolt-compatible computer for professional creative workflows. Thunderbolt power for today. Enough capacity for current and future projects.

Package Contents
  • 5big DAS Array
  • External Power Supply (12V/12.5A)
  • Thunderbolt Cable
  • Quick Install Guide
  • CD
  • Cable Management Clasp
Limited Warranty3 Year
Weight (Approximate)7.60 kg