Six Cores against Four: Does It Make Sense?
The systems based on quad-core processors do not get popular very rapidly. Many users believe that dual-core CPUs offer the best price-to-performance ratio. And they are partially correct. A lot of contemporary popular applications, first of all numerous games, can’t use all the resources of quad-core CPUs. That is why most users have very good reasons to consider the ability to split the load into even more, namely six, parallel threads to be obviously excessive. In these conditions the future of desktop six-core processors is pretty arguable, which may make these processors a very niche solution, at least shortly after they appear in the market.
However, there is also a different opinion. I have to remind you that almost all resource-hungry applications dealing with media content creation and processing have been long and very successfully optimized for multi-threaded environments. And in this case another increase in the number of CPU cores may become very handy, especially since more and more computer users start getting involved with video processing.
In order to see all the benefits from the increase in CPU cores from four to six, we decided to find out how great will the performance gain be from two additional cores in existing applications before we actually move to direct comparison between six-core Istanbul and top quad-core processors. To answer this question we performed a test session where we compared the performance of two systems with six and quad-core processors working at the same clock frequencies.
In other words, we compared a system built around six-core Opteron 2435 working at 2.6 GHz against a system using quad-core Phenom II X4 910 that also worked at 2.6 GHz clock speed. To ensure that we perform this comparison in testing conditions as close as possible, we clocked DDR2 memory at 667 MHz in both systems. Our experiments showed that with DDR2 SDRAM working at the same frequency in both cases the Socket F platform can ensure the same memory subsystem performance as the Socket AM2+ platform, even though we use Registered modules in the first system and Unbuffered in the second.
Overall, the CPU with six computational cores can really raise the performance bar. Two additional cores provide a pretty significant advantage during video processing and transcoding as well as during final rendering. We see the results also increase in synthetic Futuremark benchmarks that measure complex systems performance. In other words, adding additional cores to desktop processors indeed makes a lot of sense. But unfortunately, gamers will hardly be excited about the six-core desktop processors. Most games at this point can’t respond to the increase in the number of computational cores with an appropriate fps rate growth. But we can certainly find a few examples of just the opposite.
And although in this test we barely see any negative numbers among the relative performance results of AMD Istanbul processor, do not be too hopeful yet. Here we compared a six-core and quad-core processors working at the same clock frequencies. In reality, six-core desktop AMD processors that will be manufactured with the existing 45 nm process will have lower frequencies than the top quad-core offerings. And it will inevitably make top six-core AMD CPUs considerably less attractive. In this respect, Intel’s approach seems to be way more effective: this company will manufacture their six-core CPUs with the new 32 nm process, which will allow them to compete against quad-core solutions in clock speeds as well as performance in applications that do not parallel too well.
However, let’s not draw any final conclusions just yet and see how Opteron 2435 compared against Phenom II X4 965 in performance.