I'm looking to purchase new server hardware that will host my corporate intranet and a sql server instance. In most cases I can't see this server being hit by more than 20 or 30 users but I want it to be quick. I'm planning on running Server 2003 with sql server 2k and the intranet on IIS.
What I'm not sure about is the single vs dual processor and the RAM. How valuable is the dual proc? And the RAM, I plan on 1.5 GB but I wonder what the benefits are beyond that.
Perhaps with this many users it doesn't make that much difference but I can see adding more load.
RAM has always been the biggest "bang for the buck" in my experience. I'd populate the box with all it will take (up to the 8 Gb limit) before I got excited about much else. The second CPU does help (often significantly), but not nearly as much as the same amount of dollars spent on RAM. You might also want to consider things like server architecture, especially the datapath between I/O devices and the CPU... This can help a great deal if you can find a faster bus for similar money.
You really need to tell a bit more about your instalation.
Current database size and expected growth in incoming months/years.
The amount of users, even concurrent users, say not much, since it does not directly represent the workload.
Respecting the dual processor, definitely, regardless what you want to do, you would always want to have a dual. SQL Server can take advantage of it at any moment by partioning a big query or simply to attend more concurrent request. As for RAM, you don't want less than 2GB for a SQL Server plus Windows 2003 box, running IIS additionally.
I would probably not worry about the current projected use of the box. Think in terms of the lifespan of this box (3 to 5 years for most businesses). Many organizations will start off with one or two web applications, then after they see how cool they are, they decide to go for more and more web applications.
As for myself, I would go for a box with 2 CPUs, at least 1GB of ram with the ability to add more (up to 2GB) later, and a pile of diskspace (as in a raid array apart from the system disk that is at least 80GB). It sounds like a serious box, but in reality, it will probably only run you $3,000 to $4,000 depending on options. As they say in some quarters "buy cheap, buy twice".