P Riehl ,

I’ve used Daisy Disk since early 2013, and it is a delight: visually appealing, and an extremely effective way of finding and removing clutter on your computer, or identifying space hogs that might be candidates for optimizing. If you care about that sort of thing (and I understand if you don’t), this is a superb tool, and well worth the price. UPDATE October 2018: from 5 stars to 2. Disk Xray Lite lacks the visual appeal, but is free and 10-15X faster at scanning large directories (which in my case are not even that large: <90 GB). UPDATE November 2018: I appreciate the developer’s response, which I received by email (don’t know where to find it here). I did another test: Daisy Disk scanned my entire home directory in 48 seconds; Disk Xray Lite in 08 seconds (OK, only 6X faster). The latter is also visual, despite what the developers of Daisy Disk imply, and in fact while not as pretty, it is actually easier to visualize file sizes because they display as horizontal bars. I’m pretty sure the human brain is better equipped to compare the size of bars oriented in one direction to “pie slices” all oriented in different directions.

Thanks for your feedback, but the reported numbers may be inexact. I've just launched the said app and it's completed scanning of my home folder in 31.4 sec, while DaisyDisk scanned the same folder in 10.4 sec, i.e. 3 times faster. Maybe you were misled by the intermediate scanning results that the other app shows during scanning? Note that those are not really useful until the scanning completes. In all our tests, DaisyDisk has demonstrated the fastest scanning performance, in range of 3 to 20 times faster than other apps, because we put special emphasis on the scanning speed and our engineers have developed unique know-hows to achieve this. Also note that the scanning speed, while an important factor, is not all you'd want from a disk analyzing app. The visualization is what determines your efficiency of finding and removing the biggest space wasters. And again, according to our experiments, DaisyDisk's map is proving to be the most efficient method of the data presentation, in most cases. In short, it's because human mind compares visual objects' sizes much faster and easier than it reads strings of text and numbers. We appreciate your feedback and if you have additional questions or suggestions, feel free to contact our support!



UPDATE Nov 11, 2018: Thanks for the additional information. I have repeated my experiment on a clean machine and realized that the said app does not scan the entire selected folder. It skips big chunks of data, and for this reason it sometimes misleadingly appears faster. In my case, it missed the ~/Library folder, skipping 5.4 GB out of the total 5.7 GB. Actually, a lot of other folders were missing in the report too. Please, could you compare the output to DaisyDisk? Overall, when scanning actually happens, the speed is always way slower than DaisyDisk. Speaking of bars vs sectors: indeed, linear bars could be implemented as an alternative design that allows to compare sizes visually, however in that particular implementation you have a text table extended with bars, which is a suboptimal combination in many regards. I could go into lengths discussing different designs that we have considered before we landed at the sunburst map, but not sure the reviews are the right place for it :) The question is all about efficiency and easiness of use, in all senses.