Microsoft's SQL Server tends to lock up as much RAM on a server as possible. If you have 2GB of RAM, you'll notice it uses most of it. If you increase the RAM to 4GB, you'll notice it immediately starts to use most of the new RAM too. This is by design and due to SQL Server's goal of caching as much data (and SQL statements) as possible to minimize disk load and performance bottlenecks.

How do you know if your SQL Server machine has enough RAM? Or if it would benefit from adding more RAM?

Open Performance Monitor on the server and add the counter: SQLServer:Buffer Manager:Buffer Cache Hit Ratio.

You really want the average to be as close to 100% as possible. If your numbers are tracking less than 95% you should consider adding more RAM to the server.

A 100% cache hit ratio means that SQL Server is currently pulling 100% of the data requests from RAM rather than disk. Reading from RAM is always faster than reading from disk - even the new super-fast solid-state disk drives - so this is of course the preferred scenario. If you are getting 99%+ on your cache hit ratio counter, the server would likely not benefit from additional RAM right now. If performance gains are desired, you'd be better off looking at other areas (perhaps CPU or general query optimization).

If you have interest in system configuration, monitoring, and management solutions, you might want to follow the Microsoft System Center team's blog.

"What's your server's uplink speed?"

"What?"

"How fast is your server's network connection?"

"OC3 I think."

That's not an actual discussion but I could see it being a common one with many people getting started in dedicated hosting. Non-administrators just assume the server is "connected to the Internet" and can perform at whatever speed the host advertises for network bandwidth. That is of course not quite accurate.

When reviewing differences between our standard managed dedicated hosting options and some cheap competitor options, something that shows up (much more often than many would believe) is the server's uplink speed. This is the speed of the server's connection to the web host's network core. It amazes me that some hosts have default uplink speeds of 10 Mbps then charge for an increase to 100 Mbps and charge further for an increase to 1000 Mbps (gigE).

Now, I can understand why the host would do that because the lower the uplink speed, the lower the total impact on their overall bandwidth. It would also allow them to use older network equipment (10 Mbps wasn't bad 10 years ago).

But how does that impact the hosting client? Well, it can actually have a rather large impact on the client.

Time Warner Road Runner is the ISP I use at home and when things are running well I get about 6 Mbps of download speed. How many concurrent users at 6 Mbps would it take to saturate a 10 Mbps uplink? Not many. It is more than just 1.5 because visitors don't all click at exactly the same second, but still, anything busier than just the smallest of sites is likely to see a performance impact if their server's connection is only 10 Mbps.

100 Mbps is a lot better and might be fine for small sites at an average time during the day. We host servers for many clients though who burst past 100 Mbps on the servers and who would notice performance impact at these levels.

I mention "might" because there are additional factors. Like what happens if your site is medium sized and justifies running web and database services on two different machines? That means that not only do you have visitor traffic using the uplink port, but also the communication and data being transferred between the web and database server... and you want that connection to be fast because applications can slow down quickly if the database becomes a bottleneck.

At ORCS Web all of our servers have 1000 Mbps (gigE) uplink connections to our network core. This provides for excellent burst speeds as traffic increases on the servers, great low-latency connections between the web and database servers, and no network impact when our managed backups are running. Could we save some bandwidth costs with slower uplink speeds? Sure. Could we save some network costs with older equipment? Sure. But our focus is not on providing a "cheap" solution with potentially client-impacting shortcuts just to make more money. Our focus is on providing quality solutions at competitive rates. Our focus is on maximizing value for our clients and providing solutions that best meet their needs both short and long term as their businesses, and therefore their web sites and applications, grow over time.

What's your server's uplink speed?

This is a follow-up to a recent blog post titled "Managed Web Hosting - Compare Features and Services".