|Corsair Dominator 6GB DD3 Memory Kit TR3X6G1600C8D|
|Reviews - Featured Reviews: Memory|
|Written by Miles Cheatham|
|Sunday, 01 February 2009|
Page 5 of 8
Testing Methodology: DDR3 RAM
Before the testing really begins, there are several settings to be adjusted in the BIOS. Many combinations of the CPU's BCLK are matched to a specific memory multiplier, giving us the desired RAM (and CPU) operating speed. When high-speed DDR3 is tested, a 1:1 memory multiplier is combined with the standard BCLK to obtain baseline readings; the standard BCLK is presently 133 MHz found in Nehalem based i7 series of desktop processors. When high-speed DDR3 is tested, a memory multiplier is combined with the standard BCLK to obtain baseline readings; the standard BCLK is presently 133 MHz found in Nehalem based i7 series of desktop processors. When we begin setting the baseline parameters memory voltage and timing are always left at the manufacturer's default values, which in the case of the Corsair TR3X6G1600C8D memory kit is 1.65 Volts and 8-8-8-24. We then subject the memory to around ten passes with with MemTest86+ to assure the sample we received is not having problems to begin with.
In most cases we will then simply use the Dram for several days in every-day computing activities including several hours of gaming; this is primarily to get a feel for what the sample has to offer. After each and every change to the BIOS, the system is restarted and all RAM modules are automatically tested with MemTest86+ for one full pass. Since the modules are not yet overclocked, one pass is usually sufficient to determine if a bad part exists. Later, once we begin to overclock the memory, these tests are a good way of quickly pre-screening stable configurations. Once the test pass is complete, we move onto the synthetic benchmark tests. Here at Benchmark Reviews we use the following test suites and applications:
After all of the tests have been performed at the default memory clock speed, which establishes the baseline reading for our comparisons, we then increase the front side bus to overclock the RAM without adding any additional voltage or changing the memory's stock timings. Our theory is this: a module that overclocks without additional voltage or changes to its timings is going to perform better than a module which requires you to potentially damage it or void the warranty. Another way of looking at this is that if a module overclocks well without added voltage or lax timings, it is likely that there will be more headroom if addition voltage is applied.
We at Benchmark Reviews are fully aware that many sites turn up the voltage and apply dangerous amounts of power to the modules so that they can unlock that last megahertz; but if I begin down that road where will it end? Do I then start writing reviews where I apply liquid nitrogen cooling to the RAM? Do we volt-mod the motherboard and apply so much power we ruin expensive parts and equipment? In the end, we decided that overclocking will be done at the stock voltage for benchmarks, because I believe most enthusiasts are going to aim for the same goal. If on some rare occasion I determine that adding voltage would potentially return large performance gains, then we will add up to 0.2V to the default volt rating.
In each synthetic benchmark test Windows Vista 64 was booted fresh and the application was opened. Once the system was ready, we perform a single test-run of the benchmark, followed by three recorded tests. At the end of the series, we average the three results for the final score. Sometimes it is very difficult to get broad results between the memory modules tested, so we use several different speeds of memory from participating manufacturers. Benchmark Reviews is very serious about performance, which is why we test the products against as many benchmarks as reasonably possible. Not every test suite is effective in these reviews, and some often calculate processor and other system components into the score. This is what makes a RAM review difficult: unless all of the modules compared have the exact same rating and the CPU operates at the exact same speed for each and every test, the comparison is always going to be subjective.