Windows 7 Bridged Networking driver CPU usage

[parps]

Hello,

I have recently installed Virtualbox 4.2.4 r81684 on Windows 7 Professional 64-bit. Immediately after installation with the default options, even before configuring a VM, CPU usage as reported by Task Manager hovers between 10 - 12% which is around 100% of a single core. The service in question is "System" which I believe includes kernel mode drivers.

Uninstalling Virtualbox immediately drops CPU to 0%. If I reinstall but uncheck Bridged Networking in the installer, it installs fine and CPU remains at 0%. I can probably survive with NAT/host-only networking but bridge mode would be good to have. Bridged mode seems to work fine apart from the CPU usage if installed.

Has anyone experienced this, or have any suggestions? My network devices are "Atheros AR9485WB-EG Wireless" and "Atheros AR8161/8165 PCI-E Gigabit Ethernet Controller".

Thanks in advance

[noteirak]

What happens if you install with bridged mode and reboot, do you still see the CPU usage after the reboot?

[parps]

Yes I have rebooted numerous times trying to resolve the problem. No effect.

[noteirak]

In Task Manager > Performance > Ressource Monitor... (bottom), check
In the overview tab, check System, and then it should show you the disk usage, network, memory for it. Anything unsual? Or you can attach the screenshot so we can have a look

[parps]

Screenshot attached.

I have narrowed it down to the "Atheros AR8161/8165 PCI-E Gigabit Ethernet Controller". If I disable this in device manager, CPU drops back to 0%. I don't currently use it anyway so my problem is solved I guess But it would be good to know the cause. Driver is up to date as far as I'm aware.

Thanks for your help noteirak

[noteirak]

You should post on the BugTracker about this, with as many information as possible (driver version, etc) as it looks like a bug to me.
Please post back here the link to the ticket so progress can be tracked, and if other people with the same issue seek status, they can trace it.

[parps]

Done.

Ticket number is #11304

Thanks again

[justanotherguy]

I am experiencing the same issue and can shed a little bit more light on the cause.

I'm using WIndows Server 2008 R2, unlike the OP I have used the VMs etc but this install is only a day old. During my troubleshooting, I found that if I uncheck the box for the VIrtualBox Bridged Networking Driver on the network adapter (right click network adapter, Properties, uncheck box and Close) the CPU usage goes back down to 0%.

I have a few Wired NICS and a Wireless NIC and found that keeping the box checked on the Wireless NIC did not cause any issues with the CPU. I have a few different Wired NICs as well and so I can only surmise that the problem affects Wired NICS only.

Parps, could you update your ticket to reflect that the problem is with the VirtualBox Bridged Networking Driver on Wired NICS only?

Edit: System details: Windows 2008 R2 Datacentre (64 bit) - VirtualBox 4.2.6 r82870 -- CPU usage is only 7% for me (with 5 network adapters enabled with the bridged feature) however that 7% represents roughly 65% of one of my threads/cores on a 6 core Intel CPU.

Cheers.

[mpack]

Before concluding that's there's a bug, you might consider why an event driven network filter driver would be consuming noticeable CPU.

I would only expect it to do so when it gets lots of events, e.g. transmitting or receiving packets. If no VMs are running then it probably isn't transmitting much. Hence, I would guess that something else is firing a lot of packets at it, e.g. for network discovery. This may settle down over time, or it may be evidence that you need to tell Windows that this apparent network connection is safe.

[Martin]

Are both nics (wired and wireless) connected to the same network/same IP subnet?

[parps]

In my case, the wired NIC was not connected to anything. It has never been configured to any particular network, never had a cable plugged into it actually which is why disabling the device was an acceptable solution for me. I can confirm that justanotherguy's suggestion of unselecting "VIrtualBox Bridged Networking Driver" in the device properties also works for me - there's no need to disable the entire device.