Riding the Flow

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Choosing the Best Disk Image Backup Software - Comparison Review

My PC configuration involves single big SSD to store data (currently 512GB Crucial M4). This provides best performance and convenience of single hard drive.
However, for obvious reasons it makes regular backups even more paramount - since SSDs are being generally less reliable than usual magnetic drives.
To backup data, I use 2.5" hard drive enclosure, connected with eSATAp(Powered eSATA) interface - this way only single cable is required, while providing maximum speed and transparency.

Previously I was using Windows 7 built in backups (System Image), protected with Bitlocker to Go encryption. But recently I was badly burned by this setup, when my SSD developed single faulty bad sector. It wasn't too bad, until Windows Backup failed to properly backup this and didn't indicate a fault - but aborted backup early indicating a "success". Then it became apparent only after I tried to re-image SSD using this corrupt backup - necessitating a roll-back to previous, 1+ month older backup. At least I've managed to get access to older one, which wasn't very user-friendly either (since Windows Backup stores previous backup versions inside hidden Shadow Copy instead of normal files, also it could purge old ones quite unpredictably).

So, I've started to look for more professional and transparent backup solution, and came over quite big number of alternatives. I've tested them in my configuration (backing a fast SATA3 SSD onto large, but no-so-fast external HDD).

I was evaluating particular factors:

  • Proper sector-by-sector disk imaging must be provided (with possible exclusion of free space) - I am looking to perfectly backup original disk structure. This also generally provides best backup performance for full disk backups.
  • Speed of the full backup. Ideally this should be maximum speed at which data could be written to external HDD
  • Speed of the incremental/differential backup, especially when almost nothing have changed. In this case, speed ideally should match the SSD reading speed. If it could be faster, this is a bonus, but then change tracking must not rely on assumption of third-party kernel drive monitoring file system access continuously.
  • Must support proper encryption. This will protect your personal data from falling into wrong hands. It also helps to store backup drive in alternale location (e.g. workplace).
  • Ideally, as best compression as possible, without sacrificing speed. In fact, good compression could make total backup time lower, since amount of data written to external HDD decreases
  • Ideally, should not use any kind of third-party kernel filesystem "hooks" to trap disc accesses, implement change tracking etc. While this could provide performance gains, this potentially decreases the reliability (for example could miss changes in dual-boot setups) - and making perfect sector-by-sector backup is a priority. Ideally, VSS (Shadow Copy) Windows built-in mechanism should be used to do on-the-fly backups.
  • Overall usage convenience

So there are results of my testing. To simplify, I will list only complaints, so then a tool with least complaints could be chosen.

Paragon Backup & Recovery 2012

  • Performance of "CPU-intensive" parts very bad. Backup speed dropped significantly below HDD throughput (~80Mb/s) especially when enabling both compression and encryption. CPU load was around 1 core, so appears not to be utilize multi-core CPU to full extent. Encryption appears to be especially slow (probably because it does not use AES but older/slower algorithms)
  • Can't do incremental backup images, only differentials

Acronis True Image 2013 and Acronis Backup&Recovery

  • CPU utilization is high, so uses multi-core. However, even with CPU almost fully loaded and minimal compression settings, can't compress and encrypt fast enough to saturate backup HDD throughput.
  • True Image appear to use own custom kernel filter driver, does not use standard VSS. This is potential point of failure. Backup&Recovery required to use VSS, however its more heavyweight and expensive

EaseUS Todo Backup Home 5.3

  • Does not use VSS, installs custom kernel filter driver, hence the reliability concerns
  • "Medium" compression is fast enough to saturate backup HDD throughput, but appears to be worse performing than of competitors. High compression is not fast enough.

StorageCraft ShadowProtect 4.2.5

  • Does not appear to use hashing for incremental backups. When doing incremental backup, both source drive and base image (on backup drive) are being read. This bottlenecks speed of "skipping" unchanged sectors to speed of backup HDD, eliminating speed advantage (so speed is same or even worse then as of doing full backup, only space advantage remains)

O&O DiskImage 6, 7

  • Version 7 seem to have problems with VSS (I could not manage to get it to work). Version 6 works ok
  • Two compression options, BZIP is too aggressive and slow, LZ1 is fast but poor-performing
  • Differential imaging is slow (in fact, slower than full), reads base backup a lot

Terabyte Image for Windows 2.78

  • Seem to lack multi-core support (but to be fair, still almost fast enough to saturate backup HDD throughput)

R-Tools R-Drive Image 5.0

  • Even lowest level compression appears to be too aggressive - its best of all other competitors, but makes CPU a bottleneck despite good multi-core support, and no way to tone it further down, except completely switch off
  • Running on-demand incremental backup is awkward - requires either a command line script or running a scheduled task
  • No WinPE-based recovery CD

Macrium Reflect 5.1

  • In incremental mode appears to be bottlenecked on detecting intra-file changes - this appears to be quite slow, about 150MB/sec max. This is not good, since SSD could read almost 3x times faster than that. Tries to optimize this by excluding unchanged files - but this does not optimize well with big files like virtual machine images
  • Validation is slow, almost twice as slow as HDD read speed

Active @ Disk Image Professional 5.3.1

  • No support for image mounting
  • No WinPE-based recovery CD


It wasn't an easy choice, as there does not appear to be a tool without some downsides. But based on above test results, I've selected Terabyte Image for Windows as my backup solution. It still has flaws, but they are relatively minor. The amount of flexibility/possible options is very high, while the tool by itself is very lightweight and no-nonsense. Also it performs quite fast, despite of using only single CPU core.


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