Dual Core cpu performance improvment SQL Server 2005

Hi,

I'm trying to find an approximate percentage of what would be the performance gain of using a dual core CPU instead of a single core for a SQL Server 2005 dedicated server. I've been trying to find this information for may hours but could not get anything. Could someone give me a rough estimate please?

Thank you!

Maxim

I read somewhere that a 2 dual core processor machine roughly performs equal to a 3 single core processor machine. But, I didn't do any testing to validate it.

|||Thanks for your reply, but what I would like to know is what are the benefits (in %) of having a single core, single processor VS a dual core for SQL Server 2005.|||More CPUs is always better.

However, the dual cores are technically slower than the max single cores. For example, one 3.4mhz processor, might be faster for some things and one dual core 2.0mhz. But, overall for SQL more is always better, more CPUs, more memory, more/faster hard drives, etc.|||

Maxim,

A single, dual-core CPU is about 1.7 times better than a single, single-core processor. Two, single core processors are about 1.8 times better than one, single-core processor. SQL Server 2005 processor licensing goes by physical CPU, so having dual core CPUs is a free bonus from a licensing point of view. If the bean-counters are asking you to choose between a single, dual core and two single cores, the former wins.

It also depends on your workload. For an OLTP workload, or if you have MAXDOP set to 1, queries will run on a single processor, so you are better off with single fast processor rather than two slower processors. For a DSS or DW workload, multiple slower processors are often better.

Besides, if this is for a new server, its basically impossible to still buy single-core Xeons in the two-way space, although you can still get them for quad processor boxes.

|||You are using some abbreviations I'm not familiar with (sorry I mostly speak french...). Could you tell me what MAXDOP and DSS are? (DW = Data Warehouse I presume).

We intent on using this SQL Server for a Sharepoint portal. In what category would this be?

|||

MAXDOP stands for Max degree of parallism, it is a SQL Server setting that controls how many CPU's can be used in a query. DSS stands for decision support system. What it means in this context is that you have a database that does much more reads than writes.

I would guess that most Sharepoint databases would favor reads over writes. This would affect your indexing strategy. Also, if you have long-running, complex queries that might benefit from being "parallelized" (split between multiple CPU's), then this might affect your choice of which CPU's to get.