Microsoft Sharepoint Products and Technologies Resource Kit eBook

214 Part III: Planning and Deployment
operations per second. Therefore, each server in the farm should be approximately
a 2 x 2-GHz Pentium 4 Server with 2 GB of RAM. This is a close estimate of the hardware
requirements needed for the example. If more portal sites are being hosted on
the same farm, higher hardware requirements are necessary.
Rough hardware estimates are based significantly on the type of farm being
used. Because each farm type has resources broken down in different ways, they
have different operations-per-second estimates. A single server farm with MSDE
cannot exceed five concurrent database jobs, and therefore, cannot realistically
exceed five operations per second. For cached operations, a slightly higher operations-per-second
rate might be achieved, but on average, it will remain about five
operations per second. A single server farm with SQL Server will be able to support
around 6 to 7 operations per second for each 1 GHz of processing speed. If the
server is constantly doing a lot of indexing, this number will be lower, as the server
will be using processing resources on indexing.
A small server farm environment will be able to support approximately 7 to 8
operations per second per 1 GHz of processing speed. Again, if there is a lot of indexing,
the number will be lower. You should restrict indexing activities to periods of light
usage, such as late at night, in single-server and small server farm environments.
Medium server farm environment can handle more requests, not only because
resource-intensive operations such as indexing are offloaded, but because a
medium server farm can support more than one front-end server. It is the front-end
Web servers and search servers that mainly affect the number of operations per second
for users. A medium server farm can support approximately 9 to 10 operations
per second per 1 GHz of processing speed on the front-end Web servers.
Large server farms can handle more requests still because the search and Web
components are running on different servers. It’s difficult to estimate the capacity of
large server farms without knowing the breakdown of search requests versus normal
requests. A rough estimate is that a large server farm can support 11 to 12 operations
per second for each 1 GHz of processing power on the front-end Web servers, but
this is a general approximation.
The numbers provided in this section are general guidelines and approximations,
as actual results will vary based on the exact hardware you are running. It is
important to run capacity planning tests on your servers to ensure they will be able
to perform adequately. This testing is especially important in a large server farm
environment, where it is harder to gauge the actual hardware requirements without
knowing the exact environment specifications. For example, if there will be a lot of
searching going on in a large server farm, it is important to have many search servers
and to test the whole farm using a script that simulates many searches. Full coverage
of testing servers for capacity will be provided in the “Testing for Capacity” section
later in this chapter.