re: PC Discussion - Gaming, Performance and Enthusiasts

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Does math apply here? 2133/1.6*1.5 = 2000 which is still better than everything else at that price... not sure if it works that way though.

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That formula doesn't make much sense or really mean anything. DDR3 has a standard voltage of 1.5v, as defined by the by the Joint Electron Device Engineering Council (JEDEC), which sets speed, latency, and voltage standards for RAM manufacturing. However, depending on the manufacturer and component quality, the RAM might require additional voltage to run at high speeds. For example, a manufacturer tests a batch of RAM modules and determines that they are fit to be sold as 2133MHz if the voltage is set to 1.65v, and the timings are adjusted to 9-11-11-31.

In recent years, Intel’s spec sheets have claimed to only support 1.5v RAM, and this has been misinterpreted heavily and has caused people to fear using any RAM modules that require more than 1.5v to run at their rated speeds. This is simply an unfounded fear, and it stems from the fact that the JEDEC standard voltage is 1.5v, with a margin of error of no more than 5% more voltage for utmost stability. Naturally, Intel designed their memory controller based on this standard. If you look at the whole picture, the CPU's IMC natively only supports DDR3-1333, and you wouldn't want high-voltage modules of that speed anyway since they'd be inferior products (low-binned hardware). Any RAM from a reliable manufacturer (Mushkin would be considered reliable) that’s rated for 1.65v, will be stable at 1.65v. It’s only because the voltage exceeds the JEDEC standard that Intel deems it the same as “overclocking” (just like any RAM that exceeds 1333MHz) and is therefore not “supported.” Your CPU’s IMC can handle it.

Nevertheless, this applies mostly to higher speeds, where it becomes absolutely necessary at a certain point to up the voltage—as speeds approach 2133MHz and beyond, the 1.5v modules become rarer and more expensive. It's pretty much expected that a 2133MHz module is going to run at 1.6v or higher unless A) it has high latency or B) it's a very highly rated kit like the Dominator Platinums that cost way more. The cheapest 1.5v 2133MHz kit has a CAS Latency of 11 and is $83. There is a 1.5v CL10 kit for $85 (Mushkin Blackline as well). Not really a big deal unless you plan on tweaking the RAM rather than just setting it to its rated specs and leaving it. Then there's some Corsair 2133MHz CL9 1.5v RAM for $139. The price jumps up there pretty quickly.

Keep in mind that you will need to go into your bios and set the Intel XMP profile for the RAM. Otherwise, it will likely run at 1333Mhz. I'll tell you how to do this once you get the build running.


So, in summary: Nothing to worry about. I'm running 1.65v modules myself. 2133MHz CL9. Mine were rated for 1.6v but because I severely overclocked my CPU, I needed to pump more voltage into practically everything else on the motherboard to help stability.