Adjust your RAM timings to reach CPU clock limit!

[Davekyn]

I understand raising the voltage will assist in stability for higher speeds and/or lower latencies with 2.1v being relatively safe for most modules of DDR800, however I am still struggling understanding timings is all.

I'd like to speculate on some good info I found on Memory Overclocking from Toms Hardware:

MEMORY TIMINGS
Overclocking Guide Part 2: Suggested Components and Settings | Tom's Hardware
Here the intro paragraphs sates... "Slower-than-stock timings increase RAM stability as it approaches its clock limit. The major rated latencies, tCAS-tRCP-tRP-tRAS, should be set to 5-5-5-15 while searching for the CPU's best clock speed".

SPECULATION... My Corsair Twin X PC6400 C4 timings are stock at 4-4-4-12. I just want to get the TERMS right here :)(I take it latencies are the numbers given to measure timings?) So by following this guide I am Raising the Latencies which will provide better stability? ...while searching for the CPU's clock limit as Para 2 explains...

The second Para reads as "Lower timings increase performance, and once the CPU's limit has been found, the lowest stable memory timings can be sought. The concept is to lower one latency setting by one cycle at a time, retesting until instability is found, and raise it back to the lowest setting where instability wasn't an issue. Repeat this procedure with each latency setting until the lowest combination is found. This type of testing often results in a locked system that requires clearing the BIOS, so make sure to record all BIOS changes before trying a change that might require starting over from the beginning.

OK, my question here...in what direction is it best to work with the timings 5-5-5-15 when lowering one latency setting by one cycle at a time...Right to left as in 1st start with the timing of 15 (tRAS-tRP-tRCP-tCAS) or Left to right with the 1st timing 5....or does it not really matter?

I take it after doing the restarts and finding the best combo of lowest timings that will get you back into windows you guys would run Prime95 and or some specified Ram program???

Thanks for your patients, any pointers or answers to my questions will be appreciated.
Cheers

Hers a few other links I read from tom:)
MEMORY OVERCLOCKING:
Overclocking Guide Part 1: Risks, Choices and Benefits | Tom's Hardware
Stable Memory Timings
Overclocking Guide Part 3: How To Gain 81% For $27 | Tom's Hardware

[Yellowhello]

Okay. By slower than stock timings, that means a lower number (i.e. 5 to 4). the number represents the number of cycles the memory (PLEASE correct me if I am wrong) takes that the given frequency between giving and receiving a command. So, the tighter the timings (the lower the number), the faster the memory operates. Sorry if I'm giving you false info, hopefully some one will verify my information.

[Davekyn]

Thanks for the input. I did think the guide was opting to have me change my stock 4-4-4-12 to 5-5-5-15......But after reading what you have said and how you explained it, I know longer know. Mabey I am meant to go to 3-3-3-9 or something?

Can anyone else explain this also...
Cheers

[Capper]

OK....where to start....

First, I have a problem with their methodology used......to find the max OC of your CPU, or any hardware for that matter, you need to isolate it from the rest of the system.....which means you want to remove everything else as a possible cause of failure. so saying that, simply increasing the latencies to 5-5-5-15 won't do that. You'll want to drop the memory divider, and run your memory as low as possible (maybe DDR2-400 or 533), this way you can really make sure you are finding your CPU's max clock speed without worrying that the memory is causing issues......loosening the latencies will only do so much.

As far as memory settings, and what they mean....a very good, and simplified guide can be found here at TechARP, go to the Memory Subsystem section
Tech ARP - The Definitive BIOS Optimization Guide

As to testing, look at our memory reviews, and how we test for versatility, dropping the CAS latency usually mean dropping the clock speed, or increasing the voltage 9something we only recommend doing in moderation). Use Memtest86+ v1.70, if memory will pass 20-25 cycles, I call it stable. then move on to Super Pi, this combination will help you find the best settings for your memory.

Originally Posted by yellowhello

Okay. By slower than stock timings, that means a lower number (i.e. 5 to 4). the number represents the number of cycles the memory (PLEASE correct me if I am wrong) takes that the given frequency between giving and receiving a command. So, the tighter the timings (the lower the number), the faster the memory operates. Sorry if I'm giving you false info, hopefully some one will verify my information.

You have it backward.....lower the latency from 5 to 4 is actually speeding up the memory, but the rest is correct.