AMD Opteron 248 vs. Intel Xeon 2.8: 2-way Web Servers go Head to Head

The Database Server Bottleneck

There is almost always a bottleneck in hardware tests — ours was the database. The majority of web applications require a database server for data retrieval and storage. We used Microsoft SQL Server 2000 as our back-end database server for these tests. Prior web server tests that we’ve performed have been on single or dual CPU servers and have reflected accurately the performance of the hardware on which the tests were run. When we started running the tests on the servers, specifically the Opteron, we found that the tests had hit a wall and were not reflecting accurately the performance of the hardware. The issue was I/O, the largest bottleneck in any database server. We were putting so much load on the servers to get the CPU working hard that the database server I/O was maxed out. This, of course, caused the web tests to hit a performance plateau as each request run against the web application server has to wait for the database to complete its data transaction.

So how do you get rid of an I/O bottleneck? Well, if you have the resources, you throw more disks at the problem. The problem with that solution is it gets expensive to have massive RAID arrays that are just used for testing purposes and have to be continually upgraded as hardware improves. To get around this expensive issue, we used the fastest and most inexpensive storage medium you can — memory. We created a RAMDISK and put the database on that new drive. RAMDISK has been around for years and has matured over the years to solutions that can be formatted as NTFS drives, which are easier to manage. Effectively, a RAMDISK partitions a portion of physical memory and allows it to be formatted as a drive letter that is available to the operating system.

Once we solved our bottleneck, the testing began and as you read on, you’ll see how the different platforms performed while under real-world web application load.