Why does file recovery take so long?

File recovery is the process of restoring lost or deleted files from storage devices like hard drives, USB drives, SD cards, etc. When files are deleted or lost due to accidental formatting, corruption, or hardware failure, specialized file recovery software can help get those files back.

However, file recovery is often a lengthy process that can take hours or days to complete. There are several reasons why file recovery takes so long even with advanced data recovery tools.

Scanning Storage Media for Lost Files

The first step in file recovery is scanning the storage device to look for traces of lost or deleted data. This scan searches every sector on the drive to build a map of where files might still reside.

Storage devices today have extremely large capacities up to 16TB for consumer hard drives and even higher for enterprise drives. Larger drives take longer to scan completely. A full scan of a 1TB hard drive can take 6 hours or more.

In addition, if the file system is corrupted, which is common when files are lost, the data recovery software must rebuild file tables and directory structures to make sense of the underlying data. This adds considerable overhead to the scanning process, slowing it down significantly.

Advanced file recovery tools use algorithms to search for patterns that indicate the presence of specific file types. This targeted scanning can speed up recovery but still takes substantial time.

Extracting Recoverable Data

Once the initial scan finds traces of lost files, the next step is extracting the usable data. This process is akin to reassembling the pieces of shredded paper back into coherent documents.

Extracting data fragments and reconstituting corrupted files requires intense processing power. Recovery tools have to rebuild file structures, validate file integrity, error-check, and arrange data back into usable files.

This is a very input/output intensive procedure with a high processing load. The recovery software has to ensure recovered data is intact and stitch it back together without losing file consistency.

Large files like photos, videos, and office documents take even longer to reconstruct from fragments versus small text files. The complexity and number of corrupted files drastically lengthens the extraction phase.

Writing Recovered Files to a Storage Device

After scouring the source drive for recoverable data and rebuilding the actual files, the last step is writing those restored files to another storage device like an external hard drive. This is necessary to avoid overwriting deleted data on the original drive.

Writing thousands of files to another device also adds significant time to the recovery process. Transfer speed depends on the drive interface like SATA, USB, etc. and drive specifications like HDD or SSD.

For example, writing 10,000 files sized at 1 MB each to an external HDD over USB 3.0 would take around 8-10 minutes. That does not include recovery time for larger media files. The writing process can take hours for recovering complete hard drive contents.

Impact of Data Fragmentation on Recovery Speed

File fragmentation is when pieces of a file are scattered in different locations on a storage device rather than in contiguous blocks. This occurs naturally over time as files are modified, deleted, and overwritten.

Fragmentation severely degrades file recovery performance. When a file is fragmented, the recovery software has to find and chain all the fragments together across multiple locations on the drive.

Heavily fragmented files, like those in long-used hard drives, have pieces clustered all across the disk rather than in neat order. This massively increases scan times and resources needed to rebuild those files.

Drive Health and Hardware Issues

If the failed drive has physical issues like bad sectors or a damaged read/write head, that also multiplies file recovery times. Drives with mechanical or electronic problems have degraded read performance, taking much longer to access data.

Low-level disk errors force the recovery tool to repeatedly reread sectors and use advanced error correction to extract data. This adds to the overall time requirement.

Drives that have been through physical trauma like impact or water damage are especially prone to performance issues that hold up data recovery. The worse the drive damage, the less efficient and slower the extraction process becomes.

Encryption and Compression

Encrypted or compressed storage devices present additional obstacles that delay file recovery significantly.

Encrypted volumes require the recovery tool to decrypt data after extracting it from the source drive. Decryption routines add CPU overhead, slowing down overall speed.

Compressed NTFS and exFAT volumes need decompression before files can be accessed. Decompressing entire drive images adds CPU load similar to decryption. Compressed media files like JPEGs and MP3s further increase processing requirements.

So encrypted and compressed drives take much longer to recover usable files from due to the extra computation involved.

Impact of File Size on Recovery Speed

In general, larger files take longer to recover than smaller files. Video, audio, ISO disk images, and database files tend to be very large, often several GB each. These jumbo files have more fragments to locate and reassemble.

Larger media formats like 4K video have enormous file sizes that take considerable time to reconstruct from the drive. The more big files needing recovery, the longer the overall process.

Conversely, small document files like TXT, PDF, and Office files with sizes in the KB or MB range recover faster. But more numerous smaller files can still consume just as much time as fewer big files. A drive with 250,000 small files may take just as long to recover as one with 50 large 10 GB files.

Computer Processing Power and RAM

The computer running the file recovery software also impacts speed. Recovery involves intensive disk access and data processing. Underpowered computers with old, slow CPUs and limited RAM will be far slower than modern PCs.

Ideally, a file recovery computer should have:

– Intel Core i5/i7/i9 or AMD Ryzen 5/7/9 processor
– 16GB RAM or higher
– USB 3.0/3.1 ports and 6Gbps SATA ports
– Fast SSD system drive

Powerful CPU performance, abundant RAM, fast ports, and NVMe SSD speeds allow quicker file scanning, extraction, and writing times. Insufficient computer resources becomes a bottleneck for recovery efficiency.

Type of Storage Device

Source drive type also affects recovery time. Because SSDs have no moving parts, they can process random access requests much faster than traditional hard disk drives.

Average HDD access time is around 10-15 milliseconds versus 0.1 ms for SSDs. So SSDs allow faster scanning and data extraction versus HDDs which are saddled by physical seek times.

However, the actual interface and link speed determine maximum throughput. So SATA III SSDs are still faster than USB 2.0 flash drives for recovery even though both use solid state memory.

Data Recovery Software Algorithms

Sophisticated data recovery tools use advanced algorithms and file carving methods to accelerate the process. However, not all recovery software is created equal.

Lower quality budget recovery apps use basic file carving that simply searches for file headers and copies sequential sectors until an end marker is found. This brute force method is extremely slow.

Top tier professional recovery tools employ intelligent file reconstruction and optimized search algorithms to maximize speed while maintaining data integrity. Their advanced algorithms contribute significantly to faster and successful file recovery.

Results Verification Steps

Serious file recovery tools take additional steps to verify restoration quality before writing recovered files to disk. These procedures add overhead that impact recovery time but are important for accuracy.

Verification steps include:

– Comparing recovered file checksums to originals
– Testing restored files for operability
– Checking recovered files against file system metadata
– Confirming all fragments were properly assembled

These validation measures help ensure maximum recovery precision but do extend the overall recovery workflow. Allowing the software to validate results can provide peace of mind at the cost of extra time.

Factors that Reduce Recovery Time

While many factors increase file recovery time, some elements help accelerate the recovery process:

– Newer PCs with fast SSDs, lots of RAM, and multi-core CPUs
– Healthy source drive with minimal bad sectors
– Defragmented source drive for contiguous file fragments
– Unencrypted and uncompressed source drive
– USB 3.0, USB-C, Thunderbolt, or eSATA interfaces for fast throughput
– Trimmed recovery scan area instead of full disk
– Smaller number and size of recoverable files

Optimizing these factors when possible can help reduce the time needed to successfully restore lost files.

Improving Recovery Speed with Solid State Drives

Upgrading to solid state drives (SSDs) is one of the most effective ways to speed up file recovery both on the source drive and destination.

SSDs have much faster random read performance necessary for efficient media scanning during recovery. Their lack of moving parts removes the mechanical delays incurred by traditional hard disk drives.

Without seek time limitations, SSDs allow data recovery tools to scour drives and rebuild files significantly faster. They also reduce fragmentation thanks to inline compression and wear leveling algorithms.

Recovering files to an SSD destination drive cuts down the time needed to write restored files. SATA III SSDs sustain transfer speeds above 500 MB/s versus under 200 MB/s for HDDs.

For example, writing 10,000 1 MB files takes:

– 98 seconds with a SATA III SSD
– 230 seconds with a 7200 RPM SATA HDD

So SSDs can dramatically improve both the file scanning/extraction and final writing phases of recovery. Media scanning can be upto 50% faster with SSDs according to data recovery firms.


While file recovery software has become adept at restoring lost data, the process remains time-intensive due to the complexity of rebuilding corrupted files and fragmented data. Huge storage capacities, advanced encryption, compression, and large media files present obstacles that prevent quick repairs.

However, using modern PCs, healthy source drives, optimized recovery tools, and SSD storage can help accelerate recoveries. With the right resources, patience, and accepted limitations of existing technologies, successful file recovery is possible although rarely quick. But the time investment is reasonable to recover truly valuable data.

Looking ahead, new techniques like machine learning and neural networks may further enhance recovery speeds. As storage devices and interfaces continue evolving, we can expect to see modest improvements in recovery performance. But many inherent challenges will remain due to the intricacies of data loss and fragmentation. The srewd lawyer understands that perfection cannot be expected. Some delay and effort must be tolerated when salvaging important documents from the digital abyss.