This blog post has been repurposed and reposted from an earlier version originally published on SamKnows.com. Content may have been updated for clarity and relevance.
Since the launch of Dropbox, online storage services have surged in popularity, particularly with the rise of hybrid work. The proliferation of broadband services with high download and upload speeds has made online storage services a viable, and arguably more robust, alternative to using USB sticks.
This blog post examines three online storage services — Dropbox, Google Drive, and Microsoft 365 SharePoint — to test and compare how they perform on different U.K. broadband providers.
What Was Tested and How
A 500MB test file was uploaded to publicly-accessible folders on Dropbox, Google Drive, and Microsoft 365 SharePoint. Approximately 180 SamKnows devices, deployed on the fastest speed tiers of major U.K. broadband ISPs, were instructed to download these files and measure the transfer speed. The download duration was limited to 10 seconds. A single TCP connection was used for the download measurement (mimicking the behavior of the real clients being tested).
The IP address of the server that delivered the content was recorded as well, which made it possible to trace the location the content was delivered from. The operating system (OpenWrt) on the SamKnows devices could choose to use either IPv4 or IPv6 for the transfer, without forcing the traffic to use one or the other. This ensured connection to the storage providers over IPv6 when supported by both the user’s broadband connection and online storage provider.
In all cases, the online storage services use TLS to encrypt the data in transit. On the fastest connections, this required decrypting content at hundreds of megabits per second, driving the SamKnows devices’ CPUs to 100%. This meant measuring the performance of the CPU rather than the broadband connection or online storage service. To resolve this issue, a solution was devised: after obtaining the final URL of the content (often following multiple redirects), a handle to the TCP socket (not the TLS-wrapped socket) was obtained, and data was read directly from this socket. Of course, the data was unreadable as raw encrypted bytes, but that was fine — the volume and speed of data were being measured, not the content itself. With this change applied, reliable measurements of approximately 940 Mbps were reached.
In summary, the metrics captured for Dropbox, Google Drive, and Microsoft 365 SharePoint included:
- Download speed
- The volume of bytes transferred
- The IP address of the server delivering the test content
Findings
The findings below were obtained from a sample of 9,335 tests that were run across 165 SamKnows devices in the U.K. over a two-day period in September 2018. SamKnows was used to analyze the collected measurement data. This helped to generate high-level summaries, identify patterns, and conduct deep dives into the results to understand the cause of these patterns.
Initial Comparisons of the Online Storage Providers
Figure 1 shows the average download speed achieved from each of the online storage providers. On average, Google Drive delivers significantly higher throughput than Dropbox and Microsoft 365 SharePoint. The 36% difference between Google Drive and Microsoft 365 SharePoint is significant, particularly when dealing with broadband connections in hundreds of megabits per second. Of course, these are just averages and could be skewed by a few outliers, so exploring a few more charts can help determine if a pattern forms.
Comparing Online Storage Providers by ISP and Product
Figure 2 below compares the average download speed for each of the major ISPs and products in the U.K. to each online storage service. As might be expected, Virgin’s 200 Mbps and 350 Mbps products delivered the highest absolute throughput. However, there are significant differences in the performance of Virgin’s fastest 350 Mbps product—on Microsoft 365, an average throughput of only 158 Mbps was achieved, while on Google Drive, the very same broadband connections averaged 338 Mbps. This level of difference might be expected when dealing with a very high bandwidth-delay product, but all of the online storage services tested here had hosting locations in the U.K.
On the VDSL-based products from BT, Sky, Vodafone, and TalkTalk, the same pattern could be observed. Google Drive tended to deliver the highest throughput, with Dropbox typically following second, and Microsoft in third.
IPv6 Usage Among Online Storage Providers
Testing shows that multiple online storage providers and ISPs are using IPv6 to exchange traffic. Figures 3, 4, and 5 below show that more than 50% of tests run on BT and Sky broadband connections were carried out over IPv6 when testing to Google and Dropbox. Only Google, Dropbox, BT, and Sky appeared to employ IPv6. In other words, Microsoft, Virgin, and TalkTalk did not make use of IPv6 at all. There was no discernible performance difference in the IPv4 versus IPv6 measurements.
Hosting Locations
Traceroutes were carried out to all of the IP addresses that the online storage providers served content from. In almost all cases, traffic was served from London-based IP addresses. The few exceptions were seen with Google Drive, which occasionally served content from Amsterdam, most often for TalkTalk, suggesting that there might be some address ranges that TalkTalk owns that are incorrectly geolocated by Google.
Conclusion
The measurements show that Google Drive consistently appears to be the fastest online storage service, while Microsoft 365 consistently appears to be the slowest. This difference is significant (over twofold) on very fast connections, but remains noticeable even on lower-speed connections. No ISP-specific issues were observed with any of the online storage services tested.
It is interesting to note that BT and Sky frequently use IPv6 for transfers with Google and Dropbox, while other ISPs and online storage services still rely wholly on IPv4. This shows that IPv6 can be used in production in the U.K. and deliver high performance.