Sequential Scaling Block Sizes
We have a limited number of external storage devices to compare against Seagate's Backup Plus 8TB. This is the largest single-drive backup solution on the market, so a perfect apple-to-apples comparison isn't going to happen anyhow.
In the transfer rate tests organized by block size, we see the point at which each drives hits its peak performance. Some companies optimize for specific applications, and certain interfaces struggle in other areas. Fortunately, Seagate's Backup Plus performs well in the read tests, demonstrating consistent performance that peaks around the 64KB block size. The write tests are nearly identical, aside from a large dip with 16KB blocks.
Full LBA Span Performance
Hard disks slow down when they read and write at one end of the platter. Drive vendors tune their products to start writing data on the fastest part of the platters and then move closer to the middle as they fill up. The corresponding performance reduction is linear.
Solid-state drives have the same issue writing information, but for a different reason. The read, modify and write process is especially problematic over USB, which doesn't pass TRIM or SCSI UNMAP commands to SSDs. So, performance drops off quickly if there was previously data in the block where new information is headed.
Seagate's Backup Plus starts out strong, with reads and writes just under 200 MB/s. By the end of the test, performance is down to just under 100 MB/s. Moving larger blocks does benefit performance, but we stick with 128KB chunks to get a good average of what an external drive is typically subjected to.
These are real-world file transfer tests using Disk Bench, during which we record time and throughput. The Blu-ray ISO we use is Avatar (2D + 3D Edition); the game is the directory of rFactor; and the directory copy is a 15.2GB mix that includes movies, music, PDFs, Word documents and other files.
Even though Seagate's Backup Plus appears toward the bottom of these charts, it still performs fairly well. Two of the competing products, LaCie's Rugged RAID and Adata's SE730, are high-performance units. All three of the comparison drives are also designed for portability instead of secure backup.