Memory or CPU which is more important for a webserver (IIS)

In a given budget, what is more important more memory of faster CPU

[myalom]

We are considering a purchase of a new web server for our web site .
The platforms are IIS running on windows 2003 operating system with virus scan. At present we have only one T1 line for all services - Web server, Mail server and users browsing (About 200 users).
The current web server is a Dell PE 2550 933 MHz with 512 mb of RAM purchase at the end of 2001.
The web site is an asp based and soon an aspx based application storing its content on an SQL server running on a separate server. The servers are connected on 1 gb bit switch.
The current traffic is about 30000 HTTP requests per day with spikes of 50000.
Looking at one month statistics it shows about 7000 bytes average sent per request and about 400 bytes received.
We do want to believe that traffic will continue to grow in the next few years, but it is hard to tell how much.
First - What will give us better performance - CPU power or Memory?
What would be your recommendations as far as Memory and CPU power needed?
What additional "power" would be recommended if we would like to add moderate (up to 100 requests per day) for short 10-15 minutes audio clips streaming and up to 100 requests per day for short video clips of a few minutes each? I believe that in these cases the bottle neck is going to be the connection to Internet right?
Thanks for your help
Myalo

[jtara]

I should put this answer on a macro key: it's impossible for us to answer this question.

You need to benchmark and measure. Every situation is different.

If you are constantly running at high CPU utilization, you need more horsepower.

If you are constantly running out of memory/swapping, you need more memory. If your database performance is poor due to high utilization and small memory cache, you need more memory.

If your Internet connection is saturated, or saturated at certain times of the day, then you need more bandwidth.

If you don't KNOW how much CPU, memory, bandwidth you are using, how on earth can we answer this for you?

Why are you running a server on a T1 in your office? (I presume it is in your office.) Is there some good reason this isn't co-located in a data center?

As far as "power" goes, I would go with multiple cores over the very highest clock rate. With dual-core chips overflowing the supply channels, I wouldn't build a webserver today with a single-core CPU. And memory is cheap enough that there needn't really be a tradeoff. Pay attention to the MAXIMUM memory capacity and get what you think is reasonable. You can always add more later, and it will be cheaper than it is today.

[myalom]

We are running some banchmarks. In a few days I will try to compile some results.

One of the reasons for the upgrade: We do get high utilization of CPU from time to time (more accurate data after compiling the banchmarks).

The reason we host the server in the university is mainly budget. Looking back 5 years (this is when we got a pair of servers for the web - IIS and SQL) compared to dedicated hosting, we saved a lot. We had the T1 line already in place. We probably need to get some quotes again. In the last 5 years the hardware down time was neglectatble. The T1 line uptime was also on an average very hight. We probably had handful of outages per year.

One of the reasons for my post was that a server manufacturer, given the data I posted, came back with very high performance and expansive server (2 quad core, 4gb ram, 2X150GB 15K hard drives). It does seem over kill for what we need. This server configuration is at least 8 times more on CPU and Memory then what we have. So even if we double the bandwidth, I do not think this power will be utilized.
For sure we will get 1 or 2 dual core chips. I would agree with you that memory is not expansive. I am still debating should we go with 2, 3 or 4 GB?

Thanks

[BillyS]

>>One of the reasons for my post was that a server manufacturer, given the data I posted, came back with very high performance and expansive server (2 quad core, 4gb ram, 2X150GB 15K hard drives).

You've got close to 20x times the performance. Quad cores? Those ate arguably the the bleeding edge of performance - and that ususally demands a premium.

With the rig described above, you're good for the next five years or so...

[myalom]

My general opinion about hardware: I rather by for less and more often. performance / price ratio is so rapidly changing so it does not make sense to pay in today's prices for preformance that will be utilized only after 2-3-5 years from now.
The server offered by the manufacturer is around 7K, and my thought was 1 dual xeon 2.33, 4 gb RAM 3X73gb, with 3 year warrenty for about 4.5K. In two years I can throw in another cpu for maybe additional 400-500.
Thanks for help
Myalo