Page 1: Knowledge-de-Luxx: Which RAM should i choose?
Reading through the comments on our RAM reviews and articles, and in the respective forums, we came across the fact that, quite frequently, users are in disagreement over what kind of RAM is necessary for what purpose, and which one is useful in which situation. Reasons enough for us to use our Ivy Bridge testing system for a few benchmarks to provide the answers.
PC RAM has experienced constant change in recent years - SDR, DDR, DDR2 and most recently DDR3 are the names of the trade. Clock speeds were constantly increased: starting at 100 MHz in SDR, it went through clock speeds as high as 1000 MHz; DDR3 is the current last stage of evolution, with manufacturers achieving clock speeds of up to 2666 MHz. But not only the clock speeds have changed: constraints have changed, too. Whereas DDR memory had to deal with a bad CL of 4, DDR3 modules are top class with their CL of 7. Among other things, we will get into the details of this aspect.
An equally important innovation is the fact that - in modern systems - the previously used Northbridge has been eliminated. Back in the times of SDR, DDR and DDR2, the memory controller was located there; in the meantime, the memory controller has moved to the CPU. This increases memory access, but in turn created other problems: e.g. AMD officially specifies usage of his memory controller at 1.65 V (for 24/7 usage, mind you), Intel recommends a maximum voltage of 1.575 V, and only 1.5 V for 24/7. The various memory controllers also tend to respond differently to changes in clock speed and latencies.
In times of heightened environmental awareness we also take a look at power consumption regarding the used frequencies and voltages, and we will ascertain as to whether low-voltage modules are worth using at all.
A footnote before everything else: our testing system makes use of Intel's Ivy Bridge CPU. The gathered performance values are therefore also relevant for older Sandy Bridge processors, but AMD systems will show stark differences, possibly emphasising on other sectors (ie a higher clock speed or better latency). Therefore, AMD users should see this guide as a rather rough comparison.