Server graphics support for Multipoint server


#1

I am planning to put as many stations as possible on a Multipoint server. My current prototype is a Xeon E3-1230 cpu on a Asus IP8B-M LGA1155 motherboard with Aspeed AST2050 GPU with 16MB VRAM and 8GB RAM.

My question is whether the GPU will be limiting. We will have video or interactive graphics applications running on about 1/3 of the stations.

Also, can you comment on the server design?

Thanks,
Milt


#2

Hi Milt,

Thanks for posting! This is a great question … scalability involves a bunch of hard-to-measure factors (including expectations).

Unfortunately, I would expect problems with the Aspeed AST2050 GPU on that motherboard. It doesn’t appear to be a very common or well supported part (99% of the market is Intel, nVidia, or ATI GPUs), having mature Windows WDDM drivers is critical for USB graphics to work with the GPU at all, and then performance may also be a problem.

Especially because of potential driver incompatibilities, I would definitely recommend adding a different PCIe graphics card (from nVidia or ATI) into the system. It doesn’t need to be high end, just a solid mid-range one with good price/performance. With that, it won’t be a bottleneck.

In terms of general system recommendations, I’d start first with Microsoft’s latest guidelines: http://blogs.technet.com/b/multipoint… Even if only 1/3 of the stations are doing video at a time, I’d focus in on their “video intensive” line.

The machine you’re looking at is a good one: It’s a modern memory controller architecture (Sandy Bridge), with 4 multi-threaded CPUs, 8MB cache, supports DDR3-1333 memory (and because memory and cache contention is so important when many users are sharing a machine, memory is an area worth investing in).

The next most important factor is graphics resolution. By keeping the resolution of each monitor down, you can have a lot of control over the system load. To maximize scalability, our DC-125 client (http://plugable.com/products/dc-125/ ) has a max resolution of 1280x1024 (or 1440x900 widescreen), but you might even want to bump that down via the Screen Resolution control panel in WMS Maintenance Mode to 1024x768 (or 1280x720 widescreen), to scale to more stations.

Lastly, the USB 2.0 bus will always be a bottleneck when playing motion video or games on many stations (USB 2.0 is 480Mbps theoretical / around 330Mbps practical per host controller). By adding internal PCIe USB host controller cards and spreading the USB terminals among them, you may be able to help alleviate that bottleneck.

Again, great question. I hope some of these thoughts/guidelines help. Let us know if you have any other questions, and if you can, we’d love a post here to let us know how things go.

Thank you!
Bernie


#3

Thanks, Bernie. Very helpful response.
My followup questions are:
-I do need a flash drive port at every station, so can I use the Universal Docking Station with Multipoint Server? If so, is there a way to bolt it down to a table? Or is there another solution to adding an extra USB port to the station?
-I have a couple of unused USB sockets on the motherboard. Is it just as good to connect a USB front panel hub to those rather than installing a card?
-Can you suggest a specific GPU with good performance to price?

BTW, I have already ordered both Plugable devices to test.

Thanks again,
Milt


#4

Hi Milt,

Thanks! On the USB flash drive question: The DC-125, since it’s graphics+audio+2 free ports and powered off the USB bus itself, has only enough free ports and power for USB keyboard and mouse. To support a USB flash drive at each station, you’ll want a powered hub and more free ports, and that is what separates our higher end product http://plugable.com/products/ut-1/ from the DC-125. You might want to look there.

Note with the higher end-product, it also supports larger monitors (1920x1080), but on large monitors, for performance reasons you’ll still want to manually set the monitor resolution of each station lower, to avoid the USB 2.0 bus bottleneck as you’re scaling to many stations.

By the way here’s a good video showing WMS 2011’s two different modes for USB flash drives (plug into USB terminal, it’s private to user; plug in to USB root hub on machine, it’s public to all users): https://www.youtube.com/watch?v=R5RQ4i…

For the unused USB sockets on the motherboard, it’s hard to tell – the key is if they’re on their own host controller. I’m not certain, but I think the Intel chipset used in the box you’re looking at has two separate EHCI (USB 2.0) host controllers, so it’s a matter of figuring out which physical ports are mapped to which. But assuming that they made use of both host controllers for your existing available ports, you shouldn’t need to muck with the motherboard - you’d just want to split all your USB terminals so that about half eventually route to one host controller, half to the other. You can get the current picture of what’s happening on your system via. Windows Device Manager’s “View by Connection”.

!](https://sslproxy.getsatisfaction.com/sslproxy/SWhAdDNLMG5zdGFuVGlWenmLbJDGd3CABhjZermgcystANA4T6nd0pzV0fSzBRRGOd17A4b8ZLwi6-HESbXI0pvp7WLAhHsaAb9IFUhRC8-dScBgwa3nQrw328FH6d3ofjpAgAbVUMRqLKdL2jF0BFcxa9URvFhBVSl5P2piXdk=.PNG)](http://s3.amazonaws.com/satisfaction-production/s3_images/498850/two-host-controllers.PNG)

(Here the two host controllers on my laptop are visible, with only the built-in webcam on the second one).
Note: I haven’t done any testing to confirm performance benefits of spreading across host controllers on Intel chipsets (I’m not sure if internally they share resources, such that they’re not fully independent internally).

In terms of graphics card, the best for USB graphics are actually built-in Intel graphics on the chipset (here’s some background on why http://plugable.com/2010/08/21/whats-…)

For your case where Intel UMA graphics don’t appear to be an option, the next best is a compatible card with a good ability to read data back, since that’s what happens for all graphics that ultimately goes over USB (16x PCIe; card designed for GPGPU work, which is another scenario requiring data on VRAM to be accessed quickly). I don’t like fans because of reliability issues. So if pressed for a recommendation, this one is passively cooled, although I haven’t tested it and the heat sinks may cause it to span two slots: http://www.amazon.com/PCI-Express-EN2… ($44.95)

Last note: To see the full performance of the hardware, you’ll also want to trial Userful Multiseat Linux (free trial available at http://userful.com/) alongside WMS. Userful is much snappier than Windows Multipoint Server, even with one or two terminals, and also shows more clearly what the hardware is capable of (in terms of how many terminals one machine can scale to). Comparing the two will help highlight where the real bottlenecks are.

Again, thanks for the questions and hope that helps!
Bernie


#5

Very helpful answers, thanks.

Linux doesn’t work for us as we need to use Solidworks. I now have the clients so I will test them in the next couple of days.

Do you know if we can use any kind of USB extender. I have seen USB extenders with cat5 which would be great.


#6

Hi Milt,

Unfortunately, I wouldn’t recommend USB 2.0 over cat5 extenders. All the ones that are affordable are not good (either in throughput or in configuration software), and the all-hardware ones which are good (http://www.icron.com/products/usb/usb…) are expensive.

It’s one of the reasons we include a very long 5 meter (passive) cable with the DC-125 … to provide flexibility in having the USB terminals father out from the server.

Another good way to get both distance and fan out to more terminals, are standard USB 2.0 powered hubs (like the http://plugable.com/products/usb2-hub… ) purchased with long (3-5 meter) passive extension cables (like this http://www.amazon.com/AmazonBasics-Ma…)

An alternative for more distance are active USB 2.0 extension cables like the (http://plugable.com/products/usb2-10m/ $13.10). These will work with all the devices on the USB terminals, but the two main limitations to look out for are:

  1. Active extension cables are essentially a one-port hub. USB 2.0 supports up to 5 deep on hubs and devices (max 5 in series). So starting from a port directly on your PC, you should be able to get at least 2 and possibly 3 10 meter extension cables connected.

  2. Each active extension cable (like the 10 meter one) consumes some of the available 500mA of power. So things will work fine with a self-powered dock or hub at the end of the chain (like the UD-160-A). But devices or docks like the DC-125 that are only USB powered, might find that too much of the available 500mA has already been consumed by the active extension cable.

Hope that helps. We’re very interested in how things go for you - please let us know here or drop us a line at support@plugable.com anytime.

Thank you!
Bernie


#7

Thanks again.

Well, I tried it on our existing WMS 2010 setup and the device crashed the machine and corrupted windows, so I had to reimage the drive. I thought it might work because the Displaylink site said the software was for both 2010 and 2011, but maybe the station is not.

I will try it out on my prototype WMS 2011 system in a day or two.

Milt


#8

Hi Milt,

I’d like to help through the install. Can you send a private email to support@plugable.com with how best to reach you? (it will create a support ticket, but I’ll take it).

Some background:

The hardware itself only can affect Windows via drivers that are installed, and the only drivers involved are DisplayLink’s drivers (for the USB graphics function), Windows’ built-in drivers for the audio function, and (on the UD-160-A but not on the DC-125) ASIX drivers for the USB network function. No other software related to the device itself is involved.

A common problem with Windows Multipoint Server 2010 is it doesn’t handle device changes well outside of its “maintenance mode” - it expects all devices to be configured in maintenance mode, and then remain static after that. Adding devices while in “normal” mode causes problems with device assignments to the terminals being jumbled, which can appear like a freeze or crash. It can all be cleaned up by going back into maintenance mode, but that’s not always obvious.

Multipoint Server 2011 is better at dynamically handling hardware changes. And Userful Linux is better yet (although I know that’s not an option for you).

So please loop us in, if you can. We’d like to help.

Thank you!
Bernie


#9