We currently run several DNN sites as well as several asp.net sites that all rely heavily on MS Sql.  We are upgrading (new better hardware is cheaper then the old one) and I need some advice.

First which is most important for DNN/Sql speed - Disks or Processor?  Then, is single core/multi processor or multi core/ single processor better?

Second, using Sata drives which would be better for speed?  Raid 1 or Raid 5?

Please feel free to throw in other comments if you want.

Thanks in advance.

Adding to Slavic's response...
 
I have intimate past-life experience validating and integrating system diagnostics for one of the big "pretty box" manufacturers.  I also love building up my own machines and totally agree with Slavic regarding the money you can save yourself on higher-end systems by building your own.
 
If you DO decide to build your own box, pay VERY close attention to what others have found to work for them and try to use EXACTLY those parts that have been shown to work well together.  Slavic mentioned a couple of good items/makers.  True (enterprise class) RAID card makers will publish "approved" lists for hard drives known to work with a certain RAID card.  Likewise you can find "approved" lists of motherboards for a card.  I advise that you stick to using the parts on such lists to insure you'll have as few headaches as possible in a custom build.  If you are only doing RAID 1 or RAID 10 (instead of RAID5 or RAID6) then you can probably get away with using a lower-end card but such cards may not have "approved" lists.
 
Find people like Slavic who can tell you from experience a complete package of specific parts you should consider using.  I can't tell you how many crazy, unexpected incompatabilities I've seen and helped vendors work through as they introduced new products through the "pretty box" makers.  Individually parts tend to work fine -- the trouble starts when you begin combining parts (and supporting software) from different manufacturers.

 
On the flip side, you should not feel too bad (in most cases) about paying a bit more for a prebuilt system from a major manufacturer.  While the results are not always perfect, the big manufacturers put a lot of resources into insuring all parts will play well together before offering a system for sale.  This is not because the manufacturers care so much about the customer but is more directly related to reducing the need for after-sale customer support.  For some lower-end systems, a single customer support call can erase the profit made from selling a system (just the cost of the call).  I have seen some low-end systems (including servers) sold at a loss just to compete with another maker's offerings -- adding customer support calls on top of such practices is something the big makers strive hard to avoid even if it is not apparent from the customer end of things.  During my employ for a certain maker I gained a lot of respect for the efforts put into insuring things work as they should.  Over the same number of years, however, I also witnessed a few special cases where the maker knowingly allowed a "lemon" to hit the market so the rule is still "buyer beware"...
  
 
Regarding your web/SQL config (are you placing all on one box?):

• Lots of RAM, especially if you are placing all on the same box and spinning up web server and SQL in different virtual machines (for improved security, management and disaster recovery).
   
• Multi-core procs.  The newest generation of Intel procs (the "Core i7" series) is a leap in speed over "Core 2" thanks to reworked memory access via an onboard, multichannel DDR3 controller.  This basically means that, even without the other added advancements, an i7 will be inherently faster than the same-speed Core 2. See this article that measures, among other things, a base 2.66GHz i7 920 outperforming a much-more-expensive 3.2GHz Core 2 Extreme QX9770.  As of today you can buy the Core i7 920 for $273 while the older Core 2 Extreme QX9770 is $900 (prices here).
   
  I don't intend to start an "Intel vs AMD" discussion here but, if you prefer AMD, I think those procs are also perfectly fine (plus AMD could use the business).  I happen to use Intel at work and AMD at home.
   
• Fast disk I/O for your SQL disk data.  The web server side of things usually won't benefit as much from ultra-fast disk I/O as the SQL side will.
   
• Consider teaming two GB NICs for faster connection + redundancy (not always possible to do with the onboard NIC depending on what add-in card you get)

 
If I were you, Mike, I'd ask Slavic to send you a detailed list of parts and basic config info for one of his server buildups.  Even if you don't want to build your own, it could be handy to compare parts/features/price when selecting options for a prebuilt system.

Good luck!
-mamlin

That's true.  But SQL Server and Windows can use multiple processors, as can IIS.  DNN doesn't actually care.

Multi-core are the same as multiple processors except a quad core processor is four processors on a single chip.  It lets you pack more processors in the same physical hardware.  It also affects licensing, for example, SQL is licensed per processor.  Four single processors means four licenses, one quad-core processor means one license, with the same processor power.

Beyond that, there are a ton of issues and possibilities, from using web gardens and processor affinity to Windows Datacenter edition.  If you really are serious about this, get an integrator that deals with these installations all the time.  Or spend the money and do it right, hire staff that has been working with this.

Jeff