How do I overclock my system memory (DDR3 2000) to 2000MHz?

I recently assembled a new system with the following memory and motherboard:

The memory is advertised to run at 2000MHz. However, the motherboard has default memory clock settings only up to 1600MHz. It is advertised to be able to "overclock" memory to 2000MHz. The "installation guide" that came with the memory isn't much help:

DRAM Timing Control
DRAM timing is usually set in the following order tCL - tRCD - tRP - tRAS

  • tCL = Cas Latency
  • tRCD = Ras to Cas Delay or Active to CMD
  • tRP = Ras Percentage Time or Precharge to Active
  • tRAS = Row Active Time or Active to Precharge or Row Active Delay

So 5 - 5 - 5 - 15 settings will translate to the following: tCL = 2, tRCD = 3, tRP = 2, tRAS = 5

There are a plethora of memory overclock settings in my BIOS. How should I configure them? Pics of my BIOS memory clock settings follow:

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  • I'm probably about a decade behind in my knowledge of memory clock speeds, but doesn't the memory have to match the CPU speed (or a multiplier thereof)? Maybe you can't go above 1600 because of the sped of your CPU? – Flimzy Jul 1 '11 at 1:01
  • Could be a limitation of your motherboard as well. If your board does support it, maybe try a BIOS update. – kobaltz Jul 1 '11 at 2:22
  • @kobaltz: The motherboard supports memory "overclocked" to 2000MHz, but it only has predefined settings up to 1600MHz. The memory I have is designed to run at 2000MHz, so it's only being overclocked from the perspective of the motherboard and its chipset. – Jim Fell Jul 1 '11 at 14:53
  • The short route is to up your bus speed to 250. But then you gotta think about the CPU. You'll probably have to drop the cpu ratio. Then you gotta see if the chipset needs more power. That's the short answer. – surfasb Jul 1 '11 at 22:52

Well, technically they are DDR3 1600 chips that are advertised as DDR3 2000, which isn't a true standard. To get 1600 in the first place, they took the AMD bus (200 Mhz) multiply by 2 (cause it is DDR) and multiple by the bus ratio (4, but your screen is covering it up). That's how you get 1600 in the first place. Generally, you up the bus frequency to overclock. I advise caution cause you could make your system unstable.

Since you have no idea how the 2000 Mhz showed up in the first place, I highly recommend you read an overclocker's guide. Overclockers.com has a good guide here.

You need to understand the consequences otherwise you'll spend more time and emotions troubleshooting system reliability than you will gain in performance (which IMHO will be none).

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  • Thanks for the feedback. Where do you find that they are "DDR3 1600" (sixteen hundred)? Are you looking at the "PC3 16000" (sixteen thousand)? Both the Newegg (newegg.com/Product/Product.aspx?Item=N82E16820220534) and Patriot Memory (patriotmemory.com/products/…) product pages describe the memory as DDR3 2000 capable of running at 2000MHz. – Jim Fell Jul 1 '11 at 14:42
  • You can look at the JEDEC site, which proposed the notation in the first place. Plus memory modules frequencies are generally listed in intervals of 33's. For example DDR3 800 is a bus speed of 100. DD3 1066 is a bus speed of 133. DDR3 1333 is a bus speed of 166. The PC3 16000 is its theoretical bandwidth. You take the transfer rate (2000) multiply by 8 because it is a 64 bit bus and bandwidth is BYTES per second (Bps). I again HIGHLY recommend you read an overclocker guide before you start messing with the settings. – surfasb Jul 1 '11 at 19:51
  • They describe them as capable of going to that speed, not what the chips actually are under the JEDEC specs. It's like saying the max speed of my Sentra is 110 MPH. It doesn't necessarily recommend that as the cruising speed. – surfasb Jul 1 '11 at 19:54

Per Patriot Memory product page:

These modules are engineered to reach 2000MHz (PC3-16000) at 9-11-9-27 timings...

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