Test 1: Nominal Mode
Following our traditional test method, we first wanted to check out our system in its default operation mode, i.e. when no component was overclocked. We only changed the memory frequency multiplier and memory latencies. We tried to simulate normal working conditions during this test, so we did not turn off any of CPU technologies. AMD Turbo Core and Cool’n’Quiet worked as expected: our Phenom II X6 1090T processor sped up automatically to 3.6 GHz when only three or fewer of its cores had any work to do. When under higher load, the CPU worked at its default frequency of 3.2 GHz.
By the way, talking about memory tests, we want to remind you of what AMD has done to optimize software support for its platform. The AMD OverDrive utility makes it simpler to select and test optimal memory configurations on Socket AM3 platforms because it allows changing all memory controller parameters (and also some other settings) right from the OS, without requiring a reboot.
This utility also supports Black Edition Memory Profile which is similar to Intel’s XMP technology. AMD’s implementation does not provide for storing memory profiles in the module’s SPD. Instead, they are supplied with AMD OverDrive. The concept is interesting but hardly usable because BEMP supports but a few and rather rare memory modules as yet.
AMD made its dual-, triple-, quad-, and six-core Phenom II series processors compatible with DDR3 SDRAM clocked at 1067, 1333 and 1600 MHz. The Phenom II series is similar to Core i7 in this respect whereas the cheaper Athlon II, like the Core i5 series, doesn’t support DDR3-1600. We used a newest six-core Phenom II in our tests, so we could benchmark our test system with DDR3-1600 without any overclocking.
We didn’t have any problems with the Phenom II X6’s memory controller in default mode. The system could work at any memory speeds and timings and we did not observe any inexplicable performance slumps. By the way, unlike Intel processors with integrated memory controller, AMD processors do not put forth some special requirements about memory voltage. Increasing that voltage is not dangerous for the CPU. This might be expected since the integrated controller is compatible with both DDR3 and DDR2 although the latter type works at a higher voltage.
Now let’s see what results we’ve got. First of all, we ran synthetic benchmarks from Lavalys Everest.
Quite expectedly, the system memory delivers higher and higher performance as its clock rate grows up and its timings lower. A 266MHz increase in the frequency of dual-channel DDR3 leads to a 6% boost in terms of practical bandwidth at reading. Reducing the timings by one cycle lowers the latency by 4%. However, we shouldn’t forget that today’s CPUs feature a rather large amount of L3 cache which can smooth out the difference in memory parameters in most applications. Therefore, our final opinion should be based on numbers obtained in real-life benchmarks and algorithms.
We guess the diagrams don’t need much commenting upon. It is clear that memory settings have but a small effect on system performance. In fact, you can only feel the benefits of faster memory with reduced latencies in certain applications that deal with huge amounts of data, e.g. data compression or modern 3D games. So, it is only serious gamers that should indeed care about choosing the fastest memory modules available. Contrary to the widespread opinion, professional applications for digital content processing and creation are generally indifferent to memory subsystem parameters.