IntegrityChecker data integrity checker program ported, optimized
I’ve put a considerable effort into porting my IntegrityChecker™ program (see the 15 Feb entry) to Apple’s XCode and also optimizing its performance, which is now stellar. The PowerMac Quad is capable of an aggregate hashing throughput of over 400 megabytes per second (assuming you have a RAID that can read data that fast). As someone who used to write benchmarks, compression and encryption code, I know more than a few tricks for making code run fast. IntegrityChecker uses a highly-threaded architecture that makes optimal use of all processors/cores and available hard disk speed.
The next few weeks will see its release, initially as a command line program, but later with a GUI front-end. This is a serious tool for those who want to ensure that their master files and backups are intact and undamaged—digital photography demands its own discipline if one is to avoid mishaps.
For example, suppose you regularly burn your files to CD or DVD. How do you know, both after burning, and 1/2/3/5 years later, whether those files are intact, bit-for-bit? IntegrityChecker can make that determination for you efficiently, and with a near-zero probability of missing something.
Another example would be switching computers—suppose you buy a new computer and transfer all your files to the new one. How do you know that they were transferred error-free?
IntegrityChecker is designed so that it can reside on the backup CD/DVD itself, and while no guarantees can be made, attention is paid to constructing the program such that it is likely to continue to run years from now. If you’re skeptical, consider that the compression program DiskDoubler, which I wrote a decade ago for Mac OS 9, still runs on MacOS X 10.4.5 on a PowerMac Quad (using Classic mode of course).
