Benchmarks come in many shapes and sizes. Some are extremely small, simple, and focused, while others are large, complex, and cover many aspects of a system. To help position HDXPRT in the world of benchmarks, let me share with you a little taxonomy that Bill and I have long used. No taxonomy is perfect, of course, but we’ve found this one to be very helpful as a general categorization tool.
From the perspective of how benchmarks measure performance, you can divide most of them into three groups.
Inspection tools use highly specialized tests to target very particular parts of a system. Back in the day, lo these many decades ago—okay, it was only two decades, but in dog years two tech decades is like five generations—some groups used a simple no-op loop to measure processor performance. I know, it sounds dumb today, but for a short time many felt it was a legitimate measure of processor clock speed, which is one aspect of performance. Similarly, if you want to know how fast a graphics subsystem could draw a particular kind of line, you could write code to draw lines of that type over and over.
These tools have very limited utility, because they don’t do what real users do, but for people working close to hardware, they can be useful.
Moving closer to the real world, synthetic benchmarks are specially written programs that simulate the kinds of work their developers believe real users are doing. So, if you think your target users are spending all day in email, you could write your own mini email client and time functions in it. These tools definitely move closer to real user work than inspection tools, but they still have the drawback of not actually running the programs real people are using.
Application-based benchmarks take that last step by using real applications, the same programs that users employ in the real world. These benchmarks cause those applications to perform the kinds of actions that real users take, and they time those actions. You can always argue about how representative they are—more on that in a future blog entry, assuming I don’t forget to write it—but they are definitely closer to the real world because they’re using real applications.
With all of that background, HDXPRT becomes easy to classify: it’s an application-based benchmark.
Mark Van Name
