Slow local area network upload speed in the Windows virtual machine

[hesonoo]

Using VirtualBox to create a Windows virtual machine in bridged mode, using the Intel 1000MT desktop network card. In the local area network, the upload speed is very slow, while the download speed is normal. On the other hand, creating a Linux virtual machine in bridged mode using virtio-net results in normal upload and download speeds. How can this problem be resolved

Host:
OS: archlinux
CPU: amd 5700U
vbox version: 7.0.12r159484

VM Network:
1. Bridged Adapter
2. Intel PRO/1000 MT Desktop

Download:
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 30.8 MBytes 258 Mbits/sec
[ 5] 1.00-2.00 sec 28.1 MBytes 236 Mbits/sec
[ 5] 2.00-3.00 sec 32.1 MBytes 270 Mbits/sec
[ 5] 3.00-4.00 sec 31.0 MBytes 260 Mbits/sec
[ 5] 4.00-5.00 sec 31.3 MBytes 262 Mbits/sec
[ 5] 5.00-6.00 sec 31.7 MBytes 266 Mbits/sec
[ 5] 6.00-7.00 sec 31.4 MBytes 263 Mbits/sec
[ 5] 7.00-8.00 sec 31.5 MBytes 265 Mbits/sec
[ 5] 8.00-9.00 sec 31.3 MBytes 263 Mbits/sec
[ 5] 9.00-10.00 sec 31.5 MBytes 264 Mbits/sec
[ 5] 10.00-10.02 sec 337 KBytes 176 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-10.02 sec 0.00 Bytes 0.00 bits/sec sender
[ 5] 0.00-10.02 sec 311 MBytes 261 Mbits/sec receiver

Upload:
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 384 KBytes 3.13 Mbits/sec
[ 5] 1.00-2.01 sec 0.00 Bytes 0.00 bits/sec
[ 5] 2.01-3.01 sec 128 KBytes 1.05 Mbits/sec
[ 5] 3.01-4.01 sec 256 KBytes 2.09 Mbits/sec
[ 5] 4.01-5.01 sec 0.00 Bytes 0.00 bits/sec
[ 5] 5.01-6.01 sec 0.00 Bytes 0.00 bits/sec
[ 5] 6.01-7.01 sec 256 KBytes 2.10 Mbits/sec
[ 5] 7.01-8.00 sec 0.00 Bytes 0.00 bits/sec
[ 5] 8.00-9.02 sec 128 KBytes 1.04 Mbits/sec
[ 5] 9.02-10.01 sec 128 KBytes 1.05 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-10.01 sec 1.25 MBytes 1.05 Mbits/sec sender
[ 5] 0.00-10.01 sec 0.00 Bytes 0.00 bits/sec receiver

[fth0]

You didn't say that you used iPerf, or where the iPerf client and server were located, or what iPerf command lines you used.

The upload statistics look like from an unidirectional UDP transfer, where iPerf defaults to 1 MBit/s (128 kB/s). But then it would be strange that in the first second the packets for 3 seconds were sent.

Are you proficient with ethtool and Wireshark?

[jbh]

I ran into a similar problem last week. I upgraded my host machine (Ubuntu 20.04 LTS) from VirtualBox 6.1.42 to 7.0.12r159484. The 7.0 Guest additions crashed my Windows 7 Pro x64 guest, but I got it restored and back running with 6.1.42r155177 guest additions. This guest is connected to a second bridged Intel network adapter in the host. This guest acts as a file server on the LAN, and the file transfer speed FROM guest to other computers on the LAN was slow to the point of being unusable. File transfer to the guest was fine.

I could find no solution, so I ended up downgrading the host back to 6.1.42, and file transfer speed FROM the guest returned to normal. It could be that 7.0 guest additions are needed with a 7.0 host, but since the latest 7.0 guest additions are crashing older Windows guests, I had to downgrade the host.

[ccidenta]

As I know, using a Linux virtual machine with virtio-net results in normal upload and download speeds.