Well, we can congratulate AMD. Our detailed testing of high-performance workstations demonstrated a convincing victory of AMD Opteron CPUs in all major tasks typical of systems like that. In fact, we didn’t encounter a single “heavy” task where Intel Xeon based platform could perform a way better than the AMD Opteron one.
However, it is not such an easy task to tell, which AMD platform - a single-core or a dual-core one - would be the best choice. If the application is optimized for dual-thread processing, a system with two single-core CPUs will show better results. In other applications that are capable of splitting the tasks into more than two parallel threads, dual-core processors run faster even though their clock frequency is lower than that of the single-core ones.
Speaking of different types of applications, it would make more sense to split them all into two groups. The first group will include such tasks as video encoding, image editing and some computational tasks. These applications are fitter for systems with fewer logical CPUs but working at higher speeds. In other words, a dual-processor workstation with single-core AMD Opteron processors would be the right choice.
The second group includes software that allows processing a lot of data in multiple parallel threads. For example, these are such tasks as final 3D rendering, non-linear video editing and post processing, and again some computational tasks. For this type of applications you would be better off with a dual-processor system built with dual-core AMD Opteron CPUs, as they will be able to show much better results there.
I would also like to say a few words about the viewports of professional OpenGL applications. As we have already seen, most software packages like that do not use multi-threading at all. Therefore, a single-processor workstation with a single-core CPU working at high clock frequency could be the best choice from the price-to-performance point of view. However, here we should keep in mind that the work in OpenGL applications is usually connected with some other tasks, such as final rendering, for example. So, when you are shopping for an ideal platform, you should still sum up all pros and cons before making the decision.
As for the Intel Xeon processors, unfortunately, I cannot say another really positive about them. The today’s Intel processors for workstations cannot compete with AMD Opteron. Of course, there are some tasks where these guys can show their best, but they are very few. Intel also cannot boast better quality platforms with richer feature set than those designed for AMD. Contemporary mainboards for AMD Opteron based on NVIDIA nForce Professional chipset can be an excellent choice for graphics workstation need due to SLI technology support. Xeon platforms, cannot boast anything like that yet.
Moreover, Intel Xeon CPUs have a few significant drawbacks. Namely, the today’s platforms designed for these CPUs split the system bus bandwidth between all the cores in the system, thus reducing the memory subsystem performance quite tangibly. The second significant drawback of Intel Xeon CPUs is their extremely high heat dissipation and power consumption. As a result, you need more powerful and expensive cooling systems and PSUs, because the overall power consumption of the platform is much higher.