Backup Too Slow: How to Speed Up Your Backup Again

My backup is too slow — what's causing it?

Most of the time, it's the sheer number of files that's slowing things down. An image backup, a fast backup destination, and less compression will bring the speed back.

Lots of small files cost the most time

Every single file costs time: open, check, write, close. If a few gigabytes are spread across hundreds of thousands of small files, this time per file becomes the bottleneck — no matter how fast the destination is. Typical culprits: cache folders, mail archives with one file per message, and the storage locations of document management programs.

Two measures work right away:

• Back up the first run in full. For the first run, choose “Full backup” instead of “Changes only.” That way, the check per file is skipped — on the first run, it returns the same result for every file anyway.
• Exclude unnecessary folders. You can specifically exclude cache and temporary folders in Langmeier Backup 15. Whatever stays unread costs no time.

An image copies in one go

An image backup copies the drive as a whole and doesn't go through the files individually at all. That's exactly why their number no longer matters — with a huge number of small files, an image is significantly faster than a folder and file backup. That's the most effective lever of all.

Keep in mind: the backup scope and recovery change with this. An image backs up the entire drive and is restored as a whole.

A fast destination makes the difference

A classic hard drive has to realign its read-write heads for every file — with lots of small files, that slows things down massively. An SSD doesn't have this problem and is many times faster here.

The path to the destination has a similar effect: a backup over the network runs slower than one to a directly connected drive, and with lots of small files, that really shows. Where possible, back up locally and then copy the backup to the network.

Compression costs computing time

When compressing, Langmeier Backup packs every file before it goes to the destination. That saves space and costs computing time. If you need speed and have the space, turn off the “Compress” option or choose a lower compression level. The same applies to encryption.

Two tests show where things are stuck

• Copy a large file. In Explorer, copy a file that's several gigabytes in size to the backup destination. If even this copy is slow, the problem is the path to the destination.
• Back up to a second destination. As a test, run the same backup to an internal drive. If it runs quickly there, the old destination was the bottleneck.

If nothing else has helped

If the backup stays sluggish, it's worth taking a look at the hardware. External drives without their own power supply draw power through the USB cable and run at their limit — a power supply and a short, directly plugged-in cable can fix this. On a USB 2.0 port, even a fast drive runs slowly without showing it. If you back up overnight, turn off standby for a test run: otherwise, Windows puts the computer and external drives to sleep right in the middle of the backup.

Whoever gets the number of files under control gains the most speed in backup.