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Kevin LitmanFlag for United States of America

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RemoteFX device redirection is very slow

I have been successful at redirecting USB devices (DVD-ROM, flash drive and card readers) with the help of but the access to those devices are extremely slow. So slow, in fact, that they would not be usable in production.

I added the following to the GPO of the client:
Allow RDP redirection of other supported RemoteFX USB devices from this computer - Administrators and Users
Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Connection Client\RemoteFX USB Device Redirection

I also followed and added the registry entries to allow certain devices to be redirected.
All of this works just fine it's just that all of the devices are very slow.

The clients are Windows 7 SP1 and are using RDP to connect to a VM that is also Windows 7 SP1 running in Hyper-V on a Windows Server 2008 R2 SP1 server. I am on a local LAN and all devices have a 1GB connection. Any ideas on the slow performnace of redirected USB devices?
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Kevin Litman
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I also just tested this with VM's running Windows 7 and Windows 8 both on Windows Server 2012 and I received the same result of slow redirected devicves.
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How slow? Any faster copying from a non USB drive?
If I copy from the client VM to or from the network, I get expected speeds but from a USB flash drive for instance, it takes about 15-20 seconds to open a 3-4mb picture.
What we need here are read/write speeds. Copy something from the USB over rdp then back.
Then copy from the desktop in the vm to the client and back.
I'll do that and post the results tomorrow.
USB over RDP speeds are: 600KB/sec read and 500KB/sec write. The same USB flash drive not over RDP is 60MB/sec read and 8MB/sec write. From the vm to the client I get network speeds of 120MB/sec read and write.

The USB redirection over RDP is the issue. We have been VDI for a while now with Cirtix and when we redirect USB over the Citrix ICA connection we maintain expected speeds with USB devices. But since we need RemoteFX, we cannot use the Citrix ICA but need to use RDP. Also, before anyone asks, no it's not a Citrix issue as I have completed taken Citrix out of the senario for testing.
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Aaron Tomosky
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What's the difference between USB & drive redirection? When I plug in a USB CD-RW for instance, the VM I am RDP'd into sees it as an actual drive letter (E: not "E on Client"). I can even burn a CD this way in the VM but as with the flash drives, it is extremely slow on reads and writes.
you can burn a cd? thats interesting considering ms specifically states it doesn't do that. I'm in over my head at this point as I'm a VMware and have minimal experience with hyperv. All your basic network at stats look good and at this point it's likely to be some obscure setting or patch. I noticed you have also posted on the ms forums, that may go better for you. I suggest you add the information you have given me over there.
This is being used in a Citrix environment and we wanted RemoteFX enabled so we could offload video to a server with the proper graphics card. Since RDP wasn't working so well with the USB redirection part of things, we decided to install Citrix XenApp on the physical servers with the graphics cards and then offload the graphics to hosted applications on the XenApp servers. This seems to have solved our issue by avoiding RDP and RemoteFX.