400+ RDP Hardware

For running applications you'll not need much power. The CPU becomes an issue due to RemoteFX and how the adaptive encoding handles video. It will transcode the video on-the-fly into H.264 which is extremely CPU intensive.
Here's some results from testing I did early on in the release of Server 2012 when it was ambiguous if a graphics card would offload the video transcoding from the main CPU. Results were "interesting" but using a GPU is not supported for RDSH. Plus it didn't reduce the amount of CPU load anyway. https://rcmtech.wordpress.com/2013/01/25/windows-server-2012-remote-desktop-session-host-remotefx-cpu-and-gpu-usage/

The end result of RemoteFX was excellent video quality, but you need powerful servers and reasonably powerful clients (e.g. out old HP t5000 series thin clients were definitely not going to cut it).

We eventually decided that considering the spec of the clients that would be needed (and the OS they'd have to run - we did try Wyse ThinOS without getting a workable solution) and the spec of the servers, to abandon using Remote Desktop Session Host for desktops and only use it for RemoteApp delivery of business applications. See https://rcmtech.wordpress.com/2014/09/11/why-im-not-deploying-windows-desktops-using-remote-desktop-services/

Note that Windows Server 2012 includes a feature called Fairshare that ensures that one user doesn't "steal" all the CPU and negatively impact other users on the same server, see my video testing graphs above for possible evidence of this in action.

You see, this is the part I'm stuck on and I haven't got my head around.

The school will eventually get to 400 users.  Currently it has 100 users.

3 x CiB-9224 V12 as an example based on ESXi, I'm too use to setting up one blade with all sessions going to one ip address.

How do I utilize all the hardware of 3 blades to one RDP OS?

The private school will eventually keep growing and I need a solution to keep adding hardware as they grow.

What am I missing?

the 3x was a Storage Area Network.. they are not accessed by clients but by the Servers
Clients connect to a Connection Broker(1) which then assigns the clients to a Session Host(many)

Oh I see.  So your main concern is IO for the clients data?  Is the users profiles sat on the SAN?

Everything is on the SAN

@robincm

You are correct and I need to gather more information and produces in Oreo for me to get the correct set up and the correct hardware.  My next step is to figure out what my client will be running and how I want to set up to ensure the greatest ability that that budget can bring.

I will post back shortly.

Thanks guys.

UPDATE,

Alright guys, here it is.

My client needs to have full RDP access.  The RDP sessions will have access to shared network drives and specific apps.

RDP then will be accessed from many class rooms by that student.

MY QUESTION that I'm totally stuck on:

I am too use to setting up a single blade with VMWare ESXi and two Server 2008 R2 VM's.  One is Active Directory with DNS and maybe DHCP.  The other is the RDP server.

How do I do this with 400 potential users.  As you guys have suggested, I need three blades but whats driving me mad is how do you use the power of three blades to get 400 people on one VM or have I got my thinking incorrect?

I can generally figure things out so please guide me and get me thinking and planning.

You have an RDS Connection Broker server. Users connect to this, and it "brokers" (redirects) them to RDS host servers where their sessions actually run. This way you can have many RDS host servers, and the connection broker takes care of you not needing to point each client at a specific RDS host.
The connection broker also balances the load across the RDS hosts so you don't end up with all the users on one, and none on another. You built your RDSH servers all exactly the same, so that the users can't tell the difference. You also use User Profile Disks or roaming profiles (or potentially mandatory profiles) so that user customisations stick with user irrespective of which of your many RDSH servers they get redirected onto. Likewise you redirect My Documents etc. to a network location.
Info here: https://technet.microsoft.com/en-us/library/cc753891.aspx (this is for 2008 r2, but originally you mentioned 2012?) Anyway, it's still there in 2012 and 2012 R2. Probably best to use the latest OS for a new deployment.

If you need detailed help with this, hire me. This can be a complex topic and 2000 points on EE doesn't cover it for me! :-) Otherwise, good luck!

3 Session based (2CPU x 4 Core) Terminal Servers won't  cut it.. And you need LOTS of Disk I/O operations per second (which is why I said 3 SANs clustered.  (50 users require 200 iops)*8=1,600 IOPS required

You're still going to need at minimum 4 servers with 512GB of memory each,  Each classroom will have their own 24 or 48 port switch and you will be running 10Ge to each switch. Possibly each classroom with its own vlan.. also teachers should have their own VLAN.

The step-by-step guides show you how to implement the RDS solution including high availability and load-balancing:

Also read the
Remote Desktop Service Infrastructure Planning and Design Guide
http://bit.ly/1LB5v1C

Hi guys,

I'm putting together a quote for the client and I will need ongoing support.

I am looking at this as recommended by Dell:

http://www.dell.com/uk/business/p/poweredge-r930/pd

500 users.

What ya recon?

PS.  I don't see it being cheaper to get 3 or 4 blades as i can't purchase CiB-9224 V12 here in the UK?

are they going session based, virtual machine with user profile disks, personal virtual machines?
You are still going to be short in the disk i/o area and redundancy .. 1 lightweight server for connection broker, 2 x remote desktop server managers. 2 more SANS, Networking Area, Backup Area.
Suggest Intel NUC's for the thin client rather than other Thin Clients.
http://www.windowsservercatalog.com/item.aspx?idItem=bbdded31-c5e0-8873-c071-ece8b9094d89&bCatID=1642