LTSP | LTSP Server Sizing


LTSP website recommends 256mb for the core system plus 50mb per user:

Total RAM = 256mb + (25 users x 50mb)
          = 1506mb

However Edubuntu recommends a different formula:

Total RAM = 150mb x 25 users
          = 3750mb

We recommend you choose the greater of the two, and double-it if you can (see update below).

Post install update

This memory has proved a little low, mainly because we are also virtualising Windows on the same server. If you don’t require Windows, or you are providing that service from a different server, then the higher of these two figures should be sufficient; I would certainly recommend the higher figure, because of the high memory demands of Firefox and Adobe Flash.


LTSP website states that each user is likely to require around 3% of a CPU:

Total CPU = 3% x 25
          = 0.75
          = 75% of a CPU

So a single processor should be sufficient; however this requirement doubles or even trebles if we opt to virtualise a Windows server on the installation. We would say that a minimum of a quad-core would be sensible if virtualising Windows on the LTSP server. If this is a problem for you, simply host the Windows server elsewhere; which is probably better anyway.

Post install update

We have now upgraded both servers to dual quad-core, which is proving ample capacity. I believe a single quad-core would have been ample had we not been virtualising windows on the same server.


LTSP recommend a Gigabit connection for the server and fast Ethernet for the terminals. Many fast ethernet switches include a gigabit connection, alternatively gigabit switches are becoming quite affordable.

There can be issues running LTSP via multiple switches - so if you’re buying a new switch - consider the greatest number of ports that you are likely to require.

Post install update

This has all provided to be correct - Gigabit on the server is nearly essential if you want decent performance and similarly, PCs with only old 10-base-t internet are noticeably slower to boot.

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