SQL Server 2008 R2 Express limitations CPU, nr databases, max RAM?

This Thread is quite interesting: Limitations of SQL Server Express

But I have further questions. http://msdn.microsoft.com/en-us/library/cc645993.aspx

I have two questions:开发者_Go百科

What means number of CPUs? Is it the sockets inside a server - for e.g. the server has two sockets with 4 cores on every socket - total 8 cores.

Is SQL Server Express using one core or 4 cores?

If I have several instances of SQL Server 2008 R2 Express on one machine. Is the 10GB limit a sum of all data of all instances?

Best regards,

Thomas

According to the Microsoft references it is one socket express is limited to, not one core.

From http://msdn.microsoft.com/en-us/library/ms143760.aspx:

"SQL Server is licensed per processor socket, and not per logical CPU basis."

The CPU limitation is one core, not one socket. So regardless of how many physical CPUs you have and how many cores per physical CPU, each SQL Express instance will be limited to a single CPU core.

The 10GB limit is per database, not the sum of all databases. I haven't tested this theory personally to be sure, but this size limit does not include the log file for each database; data file(s) only.

I was also searching along the net for this...

If based on dubbreak's link (link removed due to limitation)

The diagram actually shows a maximum of ONE core and TWO hyperthreaded processors (if supported).

I stand corrected after checking a little more.

Under this: http://msdn.microsoft.com/en-us/library/ms143760%28v=sql.105%29.aspx

It says "the following is considered a single processor for purposes of this table:

A single-core, hyper-threaded processor with 2 logical CPUs per socket.

A dual-core processor with 2 logical CPUs.

A quad-core processor with 4 logical CPUs."

While in here it elaborates (though its 2005 but I believe it is similar): http://support.microsoft.com/kb/914278

"
On a computer that has a multiple-core CPU, SQL Server 2005 Express Edition starts a separate scheduler for each core. On a computer that has an HT Technology-enabled CPU, SQL Server 2005 Express Edition starts a separate scheduler for each logical processor."

So it references to a single CPU socket.

In theory it looks like that but in practice I can't get my core 2 processor to go over the 50% mark if I use SQL Server Express. The sqlservr.exe process is stuck at exactly 50%.