My first time really trying to maxamize my memory

[givmedew]

Hi, for the first time ever I am really trying to get as much out of my memory as possible. I have Geil Evo Corsa Quad Channel Kit 1866 9-10-9-28.

I split the kit up and put 2 sticks in my i5 2500k and 2 sticks in my i7-920.

Right now we are working with the i7-920 D0.

I was able to get the memory to run at 1800MHz with timings of 8-9-8-25 1N currently the QPI is at 1.375v and the ram is at 1.62975v (settings not actual after droop). The BCLK is 179MHz and my CPU is at a multi of 21x. So I am rocking 3769MHz at 1.257v (from CPU-Z).

Anyways my question is as follows. I read several ram overclocking guides and one of the things I cam accross is the explination that your tRAS should be set as a total of your first 3 timings added together. So that is what I have it set at.

The thing is I commonly see people running the tRAS a few points below that number for example if someone had 7-7-7 instead of 21 they may be at 19. Or if they had 10-11-10 instead of 31 they may be at 28.

How much of an effect does this number have and should I try lowering it? Are there any other timings that are important that I should mess around with?

Also I am not sure I need that much QPI or DRAM V. I know that I am fully stable now (24HRs of prime, several hours of aida, several hours of intel, and several hours of memtest.) Any increase in BCLK I freeze up because I would need to add more CPU voltage so I know that is set as low as it can go.

I will start reducing my QPI little by little till it starts to become unstable and will do the same with the ram.

THanks

Also remember this is a x58 chipset on a RIIIE board. I am only using it in dual channel not tripple as the change in performance seemed minimal.





CPU-Z

 

[azanimefan]

seems like a weird optimization. From what i've seen it's doubtful you'll even be able to benchmark proof of any improvement from your i5 setup even with that overclock.

Ram really doesn't matter more then 1% or 2% in most intel and AMD setups... (a little more in AMD) about the only chips that need fast ram right now are APUs.


Now that i've said that... here are the rules as i understand them

Lower settings increase performance yet lower stability and the top frequency overclock you'll get from the ram. tRAS shouldn't be set lower then the sum of the other 3 numbers as you introduce stability issues when you lower it under the sum of the numbers... overall though tRAS should just be set to the sum of the first 3 numbers... as more will basically short-circut the overclocking you're trying, and lower will just introduce stability issues. so people lowering it under the sum of the first 3 numbers have a questionable grasp of what they're doing, as they're just introducing errors into their system. tCL will show you the biggest improvement in performance, and should always be the lowest (or tied for lowest) of your settings... after that it's just a matter of tweaking it.

So... what we have is a balancing situation, where the latency settings of your ram will introduce substantial increases in ram performance, YET at the same time start to limit your ability to increase the clock on the ram, and therefor affect your max scalable and stable overclock of your CPU. So you'll see there will become a tradeoff in tweaking the most performance out of your system.


However, understand it's been a few years since i've played with this, so feel free to wait for someone else to chime in on this. the one thing i DO know is the tRAS should never be less then the sum of the other 3...


here is why.

There are 3 main operations, the timings determine how long the system waits before doing the next one, and the tRAS is a "meta" timing to tell the system when to power that whole operation down. In short, if the operation takes the maximum time at each step, you'll need to keep the operation "powered up" exactly as long as the sum of the three operations maximum timings. If you power it down faster then it takes the system to complete the 3 operations (by setting tRAS lower then the sum of those three) you'll blue screen or hang-up (from time to time). Basically you're inviting into your system stability issues

 

[EarthDog]

I suggest you take a look at Woomack's article and go by that..

That said, outside of benchmarking (which in a lot of cases you absolutely will see gains - for the record) there isnt much point outside of tinkering to raise your ram above 1600MHz.