Tip o’ the Week 365 – Throttling applications’ network perf

If you ever wonder why your home network is apparently bogging down, the blame may not be just down to your broadband provider. As we increasingly use multiple devices on the home network, any one of them may be causing issues for all the others.

If you’re using an ADSL connection, the Asymmetric nature means that preference is given to data download, with only a portion of the available bandwidth allocated to uploads, since most people are browsing, streaming and downloading files more than they are serving data or putting things into the cloud.

One of the downsides to ADSL is that when you do need to upload a lot of data, it has the side effect of hammering the download speeds too. It’s even worse if something you don’t especially care about is killing your download speed through unexpected uploads, or you need to use something that requires decent upload speeds – like a Skype call or an Xbox Live session – and you get poor performance because something else is hogging your bandwidth.

OneDrive is a bit of a culprit – in an experiment, the Network Speed Test app was used in normal run of things, and saw ~18Mbps download and .77Mbps upload, which is fairly healthy.

Starting a big upload by dropping a video file into the OneDrive folder on the PC, and allowing the sync process to get going (verified by the icon in the system tray changing to show a couple of sync arrows, and the pop up balloon saying what’s happening), and things changed radically; a paltry 600Kbps download and just 150Kbps upload speed. A tell-tale is the network delay – or latency – which rose from <50ms to >700ms, which will make anything that needs real-time communications very difficult.

If you think your network performance is terrible, start by looking in Task Manager – CTRL+SHIFT+ESC – and if you think the Send vs Receive stats in the network performance tab is a bit skewed, then click the Resource Monitor link at the bottom of the window… and look at the Send / Receive columns under Network, to see which application is causing the trouble…

Fortunately, the OneDrive app has the option of imposing upload limits; look in the system tray for the OneDrive icon(s), and right-click then choose Settings. Note that you might have separate OneDrive personal and OneDrive business icons; they can be tuned separately.

Under the Network tab, you can put a value in for KB/sec (that’s Kilo-bytes per sec, rather than the Mega-bits or Kilo-bits per second of the bandwidth measurements above – remembering, of course, that 1 Byte = 8 bits, so 1KB = 8Kb), which will throttle the upload speed used by OneDrive sync. Hover over the OneDrive icon to see the

The “Adjust automatically” option sounds hopeful, but still appears to favour upload speed over download requirements, though there may be more long-term monitoring going on. If you’ve identified OneDrive sync as the culprit to your poor performance, you can also pause it for a period of time – handy if you’re on conference calls with Skype and you want to give all of your bandwidth over to that.

Still, back to the experiment: after setting the limit to 25KBps as above, there’s still plenty of uploading, but not as bad an impact on the downloads…