Measured on real images · Reproducible

How fast does OPBS read
your Macrium images?

Restoring a Macrium image is mostly one job: decompress every block and check it against the MD5 Macrium stored inside the image. We measured that exact path — every block, every hash — on real .mrimg and .mrimgx files. The script that produced these numbers is in the repo, so you can rerun it yourself.

Jump to results Macrium migration guide

The headline numbers

Median of 3 full read+verify passes. Single-threaded decompress + MD5, laptop CPU, no disks written.

152–210 MB/s — Reflect X .mrimgx (zstd)

167 MB/s — Reflect 7/8 .mrimg (QuickLZ), 859 MB NTFS

100% of blocks MD5-verified against Macrium's own digests

100 ms to parse a full 1.25 GB disk image (mrimg info)

What "read+verify" means here. The benchmark streams every block of the partition through the same MacriumPartitionReader a restore uses: each block is decompressed (zstd for .mrimgx, QuickLZ for .mrimg) and its MD5 is compared against the digest Macrium wrote into the image. A single decode error fails the read. This is the hard, CPU-bound part of a restore — writing the result to disk is bounded by your target drive on top of this.

Full results

Five real-world samples: three Reflect X images, one small Reflect 7/8 image, and a 1.25 GB Reflect 7/8 full-disk image of a real machine (931.5 GB GPT disk, NTFS partitions).

Image	Format	Compress	File size	Partition read	Parse	Read+verify
`EA9A…D76F`	Reflect X `.mrimgx`	zstd medium	17.8 MB	100 MB FAT32	3 ms	210 MB/s
`8DB9…986A`	Reflect X `.mrimgx`	zstd medium	17.8 MB	100 MB FAT32	5 ms	195 MB/s
`0EDC…131`	Reflect X `.mrimgx`	zstd medium	17.8 MB	100 MB FAT32	16 ms	152 MB/s
`6D88…845`	Reflect 7/8 `.mrimg`	QuickLZ high	1.17 GB	859 MB NTFS	42 ms	167 MB/s
`14CC…036`	Reflect 7/8 `.mrimg`	QuickLZ high	5.6 MB	16 MB (small)	8 ms	62 MB/s *

* Small-sample noise. The 16 MB partition is dominated by fixed per-call overhead; its number understates steady-state throughput. The 859 MB NTFS partition is the meaningful .mrimg figure.

Machine. Intel Core i7-8665U @ 1.90 GHz (4 cores / 8 threads, laptop), 34 GB RAM, Windows 11, Node 24, OPBS 0.6.87 build. Decode is single-threaded in this path — faster CPUs scale linearly; the QuickLZ decoder is a clean-room TypeScript implementation, the zstd path uses the native codec.

Method & reproduction

No vendor claims, no cherry-picked workloads. Drop real Macrium images in the folder, run one script, read the JSON.

Samples are real files — including a full-disk image of an actual machine, not synthetic data.
Every iteration re-opens the image (cold parser cache); the median of 3 runs is reported.
Each block's MD5 is checked against Macrium's stored digest — a decode bug would throw, not skew the timing.
No disks are written; this measures the read/verify path only.

git clone https://github.com/bobeire/opbs && cd opbs
npm install && npm run build && npm run build:native
# copy your .mrimg / .mrimgx files into imagefilesamples/ (or the repo root)
node tools/benchmark-mrimg.js 3

The script prints one JSON line per run plus a median summary — the same format shown in the table above. benchmark-mrimg.js on GitHub ↗

What this means in practice

A typical system partition reads back in minutes. At a sustained ~167 MB/s of verified decompression, 100 GB of used space is ~10 minutes of pure read — before disk-write time, which depends on your target drive.
Verification is not optional here. Every number above includes a full MD5 check per block against Macrium's own digests. OPBS will not write a byte it couldn't verify.
Parsing is instant. mrimg info on the 1.25 GB disk image completes in ~100 ms — the browse/extract/restore UI never waits on a slow index.
Chains resolve in place. Differential and incremental members browse and restore without merging first; unchanged blocks resolve against the base chain on demand.

Honest scope. These numbers cover reading Macrium images. OPBS-native .opbs images use a different codec pipeline (multithreaded zstd) and aren't measured here. Restores to disk also write at your disk's speed on top of the read numbers.

How fast does OPBS readyour Macrium images?

The headline numbers

Full results

Method & reproduction

What this means in practice

Restore your Macrium images

How fast does OPBS read
your Macrium images?