DDR3 OC Guide

[MrMooky]

Any one aware of a RAM overclocking guide that explains it while using DDR3 for the examples? All the guides I've seen seem to be using DDR2.

 

[treefrog07]

While the frequencies, latencies, and voltages of DDR2 and DDR3 RAM differ somewhat, the principles of OCing are the same. Start by changing the RAM settings in the BIOS to match the values shown on the stickers attached to the RAM modules. OC from there to increase speed and/or latencies, usually by increasing the RAM voltage and, sometimes, the northbridge voltage.

 

[gerry410]

you didnt answer his question. he's looking for a guide.

 

[Jak_Sparra]

yeah, i'm a bit puzzled about RAM timings/over-clocking and i've read quite a lot of stuff. I guess i'm just a bit thick. I'll be concentrating a lot over the next 24-48hours to get my system overclocked and stable so i can then forget about over-clocking and enjoy doing stuff again. Is there a way to add this thread to some sort of watch list so i can keep tabs on it?

I've searched google alot, and all i could find was this sketchy thread about overlcocking DDR3:-

http://www.overclock.net/amd-memory/553002-any-guide-suggestions-how-oc-ddr3.html

 

[wolfram23]

Hey not sure about a guide, but really the important thing is to get the CPU overclocked properly and the RAM will follow. But here's a little of what I've found:

-at any given latency, you can only get so much speed.
-You'll want to try to pick a base clock (or FSB) that will give you the most RAM speed possible
-There seems to be roughly 200mhz increase per latency IE: 1400mhz CL7, 1600mhz CL8, 1800mhz CL9 but these are close to maximums. I have my 1600mhz CL8 RAM running at 1412mhz CL7 currently. I had it at 1426 CL7 but I couldn't get stress test stable until I bumped the DIMM voltage up from 1.65 to 1.68. However, after a week or two suddenly my mobo only reconized 2.8gb of RAM. I dropped the clocks back down to the current 1412 with the DIMM voltage back to 1.65 and once again all 8gb were being detected. I guess what I'm getting at is don't go over the max voltage spec 1.65 as it can cause issues.

So, yeah, basically your target should be roughly 1400, 1600, 1800 mhz so that you can max out a latency but each RAM chip will be a little different. Some might do 1650 CL8 some only 1610 CL8 so it's really a matter of luck

Oh and as for Command Rate, 2T isn't really any slower. From what I read, it allows 2 clocks for initial bit finding but after that it's just as fast, so the slow down in performance is very minimal under most circumstances while the payoff is it might allow higher RAM clocks.

I also found that CL and tRCD are two big ones for stability while tRP seems to make no difference on performance. IMO just go with standard settings (7-7-7-21, 8-8-8-24, 9-9-9-27 etc). Also you can generally leave the advanced timings on auto... I've fooled around with them and also can't say there was any difference in performance. The biggest thing is CPU clock and overall RAM clock moreso than all the extended timings.

 

[J_Sparrow]

Awesome post Wolfram,

I understand alot more of the settings now. So if I understand correctly i could just stick with auto? Unless auto puts the voltage over 1.65v right? and T2 would be a better option then T1. are me talking microseconds of difference here?

 

[wolfram23]

I think the RAM by default will only be 1.5V, which is JEDEC spec. You'll want to manually adjust that up to 1.65V. The main timings you'll probably have to also set manually (ie: 8-8-8-24) but all the more advanced stuff can be left on auto. And yeah, the difference between 1T and 2T is basically microseconds or less might be a few nanoseconds. If you can get away with 1T working, well hey go for it but 2T isn't going to make much difference.