Outbound traffic from VirtualBox slow

[sebert]

I'm using Virtualbox on Ubuntu 8.10 running WindowsXP.

When I'm getting my emails with Outlook, everything is working really quick even with large emails. But whenever I'm sending large emails, it takes them forever to be transferred. It also seems to be like that when I'm uploading files with my browser. Upload is slow, download is quick. It's definetly not my internet connection in general, since up- and download in Ubuntu is always quick.

Could it be that the outbound traffic speed from Virtualbox to Ubuntu is kind of limited?

Thanks for your help!

[vbox4me2]

Using NAT sometimes causes this, you can try Bridge mode.

[leejunfan]

I'm seeing similar network performance.

I've created 2 guests, one boots kubuntu PXE from the other ubuntu server.

Noticing the network performance of TFTP/NFS doing at best 500KB/s between them I shut down the PXE guest, moved the server guest to bridged, and booted a real PC from it. I get about the same from that. However I have been able to max the guest output at about 2MB/s.

The PC booted via PXE from the VBox Ubuntu Guest, can pull from the ubuntu host at full 100Mbit (8-10MB/s).

Host Machine
AMD Turion(tm) X2 Dual Core Mobile RM-70
4G Ram
Ubuntu Jaunty (9.04) 2.6.28-server
Vbox 2.2.4

Guest Server
Ubuntu Hardy (8.04.2) 2.6.24-11
384M Ram
APIC Off
ACPI On
AMD-v Off
PAE/NX On

I've tried a couple of the different NIC brand/emulations, w/o change.

This speed issue is in at least host-only and bridged for me.