Microsoft Onedrive for Business as its name suggests is Microsoftâ€™s workplace version of its Onedrive cloud sync product. It works by syncing a folder between one or more PCs with the userâ€™s online cloud storage, similar to Dropbox. My workplace recently migrated to Office 365, which came as part of the package along with Sharepoint for syncing Team site content.
After using it for just over a week, I found my work PC running a lot slower than usual, especially whenever I copied multiple files inside the Onedrive folder. At first I thought it may be a problem with Outlook as I know it becomes fairly disk intensive if it crashes checking over PST archives. To my surprise, the culprit was a combination of the processes â€˜msosync.exeâ€™ and â€˜groove.exeâ€™, which I found to be both involved with syncing Onedrive for Business and Sharepoint. Both showed fairly high CPU time usage and when I added the columns â€˜I/O read bytesâ€™ and â€˜I/O write bytesâ€™, both already clocked up several Gigabytes. Outlook on the other hand had just roughly 50MB read and written.
One other issue I noticed was that the Onedrive for Business icon kept showing several files remaining, even after many reboots and leaving for several hours. So I followed the steps on one of Microsoftâ€™s official community threads to reset the cache. However, this turned out to be a total failure â€“ My PC got so disk intensive that it was barely usable (my work PC doesnâ€™t have an SSD) and after 3 hours, I decided to stop syncing all folders, reset the cache and add them from scratch to a new area. This time the PC was still very disk intensive with the HDD LED solidly lit for several hours until everything finished syncing and then the PC performance returned to normal again.
As I and several work colleagues still had the issue of intensive hard disk activity each time files were placed in either a Onedrive or Sharepoint folder, I decided to try an experiment. I rebooted my PC, made sure Onedrive showed â€œUp to dateâ€ and copied in a folder mostly consisting of Microsoft Publisher files - 909MB consisting of 609 files and 59 folders. Windows 8.1 and Office 2013 (which includes Onedrive for business) had all Windows updates installed to date (14th April 2014.)
As I expected, my PCâ€™s hard disk flashed way fairly steadily after this copy operation and the PC was noticeably slower, much like running a full virus scan in the background. To get a rough comparison against other applications I use, I kept every application I use open for the several hours it took for Onedrive to sync that folder. Once it eventually complete, I wanted to see how it compares with BitTorrent Sync, which is a free folder sync utility to sync between PCs. So I set up a separate folder in BitTorrent sync, set up a matching folder on another PC and copied in that same folder of 909MB. Despite BitTorrent Sync taking just a few minutes to sync that folder to my other PC, the hard disk LED flashed a lot less than at any stage over the several hours it took Onedrive to sync the same content.
Hereâ€™s the resulting usage and CPU time, against a handful of other processes:
Between msosync.exe and groove.exe, they performed just over 510GB of read activity and about 26GB of write activity just to sync 909MB! Thatâ€™s not to mention the near 73 minutes of CPU time involved (PC CPU is a Core2Duo E8400 @ 3GHz).
For comparison, BTSync.exe (BitTorrent sync process) performed just over 1.8GB of read activity and just 28.6MB of write activity to sync the same amount of content, although with the data synced to another PC instead of the cloud. While it did use 7.5 minutes of CPU time, it was running since I booted the PC, so most of that CPU usage built up over the day before I ran this test, as Iâ€™m fairly sure it took about 3 minutes to sync the content with the other computer. Although I havenâ€™t tested Dropbox or Google Drive with this content, I know from experience that they donâ€™t cause intensive hard disk activity when syncing content.
So what about syncing from the cloud back to the PC? When I returned home, I booted up my laptop which has Onedrive for Business installed and let it sync that folder in (along with ~20MB of work copied into Onedrive at the end of the day). While my laptop does have an SSD, the syncing process did manage to cause the disk activity LED to blink regularly and the CPU fan to spin up regularly despite leaving the laptop idle. It took about an hour to sync and the following is the result:
While nowhere as severe as syncing to the cloud, these two processes still managed to cause about 18GB of read activity and about 4GB of write activity. Thatâ€™s still a hefty amount of disk access just to sync in 909MB (plus about 20MB of other data) from the cloud. The CPU usage between the processes was 6.5 minutes, which is quite a lot considering this laptop has a fairly powerful CPU (Core i5 3320M).
So basically for anyone planning to use Onedrive for Business or Sharepoint folder syncing, an SSD is pretty much essential for each PC it is used on. The SSD would also need to handle a lot of write activity, considering my test showed it wrote nearly 30 times as much as what was copied into the folder (1x for the file copy operation and another 29x as Onedrive syncâ€™d to the cloud) and roughly 4 times as much when syncing in from the cloud.