I tried hundreds of hacks, but nothing worked. I've read thousands of posts from hundreds of
websites, but nothing worked. After doing much research, and testing
everything I could, I believe I have found a solution.

My host computer is a 2008/2009 Apple Mac Pro with dual Gigabit ethernet
adapters. In my particular case, I have a Gigabit ethernet adapter in
my host machine. This is the ethernet adapter in my host (2008/2009
Apple Mac Pro) machine:

Intel(R) PRO/1000 EB Network Connection with I/O Acceleration

I was experiencing the same exact slow network performance problem
between the Vista x64 Ultimate host and guest OS machines that everyone
else was experiencing.

I solved the problem by doing the following:

I disabled "Checksum Offload" and/or "Large Segment
Offload" settings on the Properties -> Advanced Settings of your
physical Ethernet adapter. That seems to have fixed the problem for me.

The problem seems to be that VMWare Workstation 6.5
doesn't like the default settings on some Windows Vista x64 ethernet
adapters (Intel Pro/1000 EB Gigabit Ethernet adapter). I wasn't having
any problems until a Windows Update (December 2008?) and suddenly
something changed, and the network folder transfer speeds were
extremely slow. So Microsoft must have done something when they pushed
out their Windows Updates for Windows Vista x64 Ultimate machines.

This is how I fixed the problem with VMWare Workstation 6.5:

First, I went into the network properties on my HOST Windows
Vista Ultimate x64 machine. I right clicked on the Local Area
Connection Adapter and went into the Properties then I clicked the
"Configure" button then clicked on the "Advanced" tab settings of the
PHYSICAL Ethernet adapter on my host machine. After click on the
"Advanced Tab" I looked under the "Property" window and I had to
DISABLE the "Large Send Offload v2 (IPv4)" and DISABLE the "Large Send
Offload v2 (IPv6)" on my host machine's network adapter.

By doing this, and after disabling the "Large Send Offload" for my host
machine's network adapter it seems to have fixed the problem, and now I
can transfer files back and forth normally, and the speed is native and
extremely fast. So the problem seems to be with "Large Send Offload"
on the Windows Vista x64 host adapter.

That is what solved my problem and worked for me, I hope this helps!

I just moved 18.5 MB of data between my host machine, and guest machine
and it now takes 1 minute and 20 seconds (instead of 1-4+ hours!!)

I hope this helps!

Thanks,

Mark

My hardware setup is a 2008 Apple Mac Pro (with dual Quad-core 3.2Ghz XEON processors, and 32GB of RAM).

I am running Windows Vista Ultimate x64 (natively) as the host OS. This seems to be a major factor in duplicating this problem. So make sure that you are running Windows Vista Ultimate x64 on a 2008 Apple Mac Pro (and booted directly into Windows Vista Ultimate x64 natively).

The problem seems to be that VMWare has an issue with extremely slow shared folder network problems, but I've discovered that this problem is related to "Large Send Offload v2" being enabled by default on the Apple Mac Pro's with the Intel Pro 1000 EB network adapters. (Other users with Intel Pro 1000 EB network adapters that are running Windows Vista Ultimate x64 have sometimes reported experiencing this same problem as well, but I can only confirm it on my setup and my system). My system is a 2008 Apple Mac Pro (8-core) system (with Windows Vista Ultimate x64 as the host OS).

If the "Large Send Offload v2" is enabled (which is the default) then the shared folder performance is completely broken in VMWare (with bridged networking enabled on the VMWare virtual adapter). It's extremely slow. If I disable the "Large Send Offload v2" on the host machine's Physical network adapter then it seems to fix the issue.

Could you please take the time to "enable Large Send Offload v2" on your host machine's network adapter (with VMWare setup for bridged networking on the VMWare virtual adapter), and then run your tests again. I believe you'll discover the same problem that I (and hundreds of others) are complaining about.

I believe this is a major bug/problem with VMWare and it really needs to be fixed. Whatever is causing this problem in VMWare needs to be addressed and fixed. It seems that VMWare has as problem transfering files back and forth (on shared folders) between the host and guest OS whenever "Large Send Offload v2" is enabled on the HOST machine's Gigabit Ethernet Adapter and the guest OS is using "bridged" networking between the host and guest OS. Not sure why this would affect the transfer speed between a host and guest OS (since it wouldn't even be going over the network) but it's a problem with the VMWare virtual adapter but something with Gigabit Ethernet adapters (in the host machine) that have "Large Send Offload v2" enabled and have "bridged" networking enabled in VMWare between the host and guest OS, causes a problem with the virtual network adapter in VMWare, and it seems to cause problems with SMB, and causes extremely slow transfer speeds with shared folders.

Again, if you want to experience the problem just get yourself a 2008 Apple Mac Pro (800Mhz FSB, with dual Quad-cores) and just toss Windows Vista Ultimate x64 on it, and I believe during the default installation (or after you install boot camp drivers?) that the Intel Pro/1000 EB network adapter has "large send offload v2" enabled by default, and if you try to transfer files between a shared folder on the Guest OS, and the host OS machine (I have Windows Server 2008 Enterprise x64 running as the Guest OS and I have Windows Vista Ultimate x64 running as the host OS and this is on a 2008 Apple Mac Pro with an Intel Pro/1000EB network adapter that has "Large Send Offload v2" enabled on the host machine by default.

If you try transfering a file with this similar setup (with an Intel Pro 1000EB network adapter with "Large Send Offload v2" enabled, and you should experience the problem that I'm (and hundreds of others) are complaining about.

The problem seems to be related to "Large Send Offload v2" causing some type of SMB problems with the VMWare virtual network adapter (and causing some crazy interference problems and causing the virtual adapter to transfer files extremely extremely slow.

Also make sure that the Guest OS virtual network adapter is in BRIDGED mode. It seems that this only happens on machines where the guest OS (Windows Server 2008 x64) is in "bridged mode" on the VMWare virtual network adapter, and that the host machine's physical network adapter has "large Send Offload v2" enabled on the host machine's physical network adapter.

I can reproduce this problem over and over and over again all day long. So please let me know if you need any further clarification, but the two things that seem to cause the problem (I believe) are:

1) The host machine must be running Windows Vista Ultimate x64

2) The host machine must have a physical gigabit Intel Pro/1000 EB network adapter in the host machine (2008 Apple Mac Pro's with 8-cores have two of the Intel Pro/1000EB integrated on the motherboard).

3) The "Large Send Offload v2" must be enabled on the physical adapter on the host machine

4) The guest operating system is Windows Server Enterprise x64

5) The VMWare virtual network adapter (between the host and guest) must be in "Bridged" mode.

Any machine that has those 5 things listed above, it causes the VMWare virtual network adapter to perform eratic, and SMB (Shared folders) between the guest OS and the host OS transfer extremely slow (about 1kbps), but if you go the host machine's Intep Pro 1000 EB network adapter's properties and click on the Advanced tab, and then scroll down to "Large Send Offload v2" and disable this, then for some reason the SMB transfers are fine.

So something with this setup and configuration (and the "Large Send Offload v2" must be enabled on the host machine's network adapter) and the virtual adapter between the guest and host OS must be bridged (in 'bridged' mode).

I hope this helps, let me know if you are able to duplicate the problem or not, and I can try to help you a bit more with duplicating this problem. I can duplicate this problem all day long (over and over) and I can see what seems to be causing it. The biggest factors seem to be the host machine's network adapter must have "Large Send Offload v2" enabled, and the guest OS "virtual network adapter" must be in bridged mode, and I believe that both of the operating systems must be 64-bit (Windows Vista x64 Ultimate on the host machine, and Windows Server Enterprise x64 as the guest OS machine).

These seem to be the easiest platforms to duplicate the problem on. Let me know if you need more information, and please let me know if you are able to duplicate the problem.

Thanks,

Mark