You might want to repost in the hardware forum, but personally, I'd go for extra memory over CPU for a DB server, as disk swapping will seriously kill query performance, no matter how fast your CPU is.

Having said that, it is unlikely anyone would be silly enough to use something like a beefy dual proc machine with 256MB of RAM...

Faster processors and extra memory generally go hand in hand.

It also depends on what your usage is going to like. A lot of queries, a lot of data, fulltext queries etc.

The question is hard to answer without the specifics on how it will be used and the type of data it will hold so maybe you can post some more details?

JAG

Without knowing more information, I definitely vote for giving priority to RAM. RAM is cheap, so I'd say load up on more than you think you need right now.

lots of queries but generally on an indexed field - very few full text searches

db used to show visitor page history, serve up page suggestions, shopping cart stuff, slicing and dicing the products in a category

inserts to the db, around tracking and logging,

not many updates

tables generally only a few thousand rows

using indexed tables for tracking which run into millions of rows.

Looks like the RAM may be part of the answer. Unless you rollup your tracking data into lookup tables, you will want some speedy drives to read those millions of rows and you'll need the RAM for the temp tables that will be created and destroyed each time. Since the tables will change often with the inserts the queries cannot be cached so proc speed is important as well.

If you rollup your data then you could use one machine to do all the grunt work and then the other to just deliver the data from smaller tables.

JAG

I assume MS-SQL Workgroup edition? If so, check to see how much RAM it can use before buying too much. I know 2005 limits you to 3GB but I'm not sure about older versions.

That being said, after seeing the impact of faster processors vs more RAM, I'm an absolute RAM junkie.

thanks for your input guys, you really helped me get my thoughts together on this one.

Hey I dont think its more economic, you thought about backup, power, windows updates, networking, redundant NICs/Switch, I/O bottlenecks...more servers = more costs

IMO the only reason to do it is scaleability not economy. A lot of RAM /Proc are needed for DB servers and web servers, its only Disks and RAID that are different but with a single 14U server you can put a 2 RAID arrays on different volumes and let the SQL have its own volume. You get the benefits of simplicity & fast data transfer of a single sertver while still maintaining separate devices for web and database servers