Deleting FF4 Cache Thrashes Mechanical HDDs?

[Hiyruu]

Can anyone confirm/deny these statements that I found on another forum?

Quoting

The new smartcache design defaults to a 1GB cache on large hdds resulting in up to 100,000 tiny files being created across a massive subdirectory tree. Mechanical HDD's cannot write(including deletion) many small files at once without flooding the hdd IO and causing thrashing. The placement you're suggesting is impossible to maintain due to the most obvious of reasons.

Windows itself is castrated to a several hundred file delete rate per second for many small byte sized files usually maxing out a core while attempting to delete so many files.

Much of the content within the cache is under a KB. this in itself is a problem because you're using a 4K cluster for every single file under 4K which adds to fragmentation and a massive increase of the On Disk size of the files, Firefox's cache caps to the actual size limit but the amount of wasted clusters can easily see 1500MB's used out of a 1GB cache setting.

Firefox should adapt an archive cache that works similar to torrent files. new and outdated cache data can be added and removed as required without a massive amount of disk thrashing.

Someone's Reply

Or perhaps not. It doesn't thrash my hard drive. If it thrashes yours, make sure it's not something you have caused, then consider filing a bug report.

http://forums.mozillazine.org/viewtopic.php?f=38&t=2139365&start=15

When I deleted my Cache manually (from the cache folder), windows had to delete 40,000 or so files, at 900 files/ sec. Will this cause any issues for the drive?

My drive is a Caviar black 1TB running at SATA 2.

 

[drescherjm]

The quote about thrashing seems reasonable.

Will this cause any issues for the drive?

No. Hard drive thrashing is not harmful. It just means the drive will take a long time to delete the files because the head needs to go back and forth.