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Any logical way to tweak ram timings?

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prophetx2

New Member
Joined
Dec 7, 2005
With tweaking the CPU I have a good understanding on how to approach it and the steps involved with it.

Now i'm trying to get a better understanding on how you guys tweak ram. I understand how to up the mhz/frequency on the ram and how the dividers work however I don't understand how you go about finding the perfect timings.

Like do you start off with lowering CAS then up voltage, then work on the other settings or do you guys have a set number in your head that you go with then up the voltage until you get there?

If this helps I'm running a DFI NF4 UT Ultra-D, opteron 170, and gskill F1-4000USU2-2GBHZ. I'm hoping to get both the opteron and gskill up to around 270 HTT at 1:1 stable. Now trying to figure out the timing to get me there gets me all confused.
 

RedDragonXXX

Senior RAM Pornographer
Joined
Mar 3, 2005
Location
Jacksonville, FL
First off :welcome: TO THE FORUMS

The key is knowing what chips is your RAM using and in your case those are Samsung UCCC's. They like loose timings and not much Vdimm, 2.9V should be more then enough. They respond best to 3-4-4 timings, but you can experiment with 3-3-3 or 3-3-4 as lower RAS to CAS is a performance giver. Trying to push 2-2-2 or 3-2 on these will not work unless you try low divider and push it down below 200MHz in which case it won't be worth it.

Ultimately at best case scenario you will be looking at 3-3-4 timing with 2.8Vdimm at around 260-270MHz.

Hope that helps :thup:
 
OP
P

prophetx2

New Member
Joined
Dec 7, 2005
RedDragonXXX said:
First off :welcome: TO THE FORUMS

The key is knowing what chips is your RAM using and in your case those are Samsung UCCC's. They like loose timings and not much Vdimm, 2.9V should be more then enough. They respond best to 3-4-4 timings, but you can experiment with 3-3-3 or 3-3-4 as lower RAS to CAS is a performance giver. Trying to push 2-2-2 or 3-2 on these will not work unless you try low divider and push it down below 200MHz in which case it won't be worth it.

Ultimately at best case scenario you will be looking at 3-3-4 timing with 2.8Vdimm at around 260-270MHz.

Hope that helps :thup:

Thanks for the info! Is there a way for you to find out the specifics about the loose timings etc, or is this a trial and error thing gathered through various forums? Frequency makes up for loose timings correct? If I can get to [email protected] i'd be happy. A little tighter is just icing on the cake. Does tighter settings even make that much of a difference when the frequency is already that high running in async (in this case it looks like it doesn't even go much tighter)? Its also rated at 2T, but i'm able to get it stable at 1t doing ddr400 with stock timings. I'm assuming as the freqency goes up, I won't be able to keep the 1t?

I really wished there was some sort of corelation to all of this. It would make it so much easier -=)
 

RedDragonXXX

Senior RAM Pornographer
Joined
Mar 3, 2005
Location
Jacksonville, FL
Freq does make up for loose timings, but not as much in vice versa.

Look at it this way; 300MHz TCCD chips running at 2.5-4-4-8 timings will perform about the same as 260MHz UTT at 2-2-2-5 timings, but if I were to up timings on UTT's with same freq to 2-3-2-5 then it's a different story.

CAS latency and RAS to CAS are the biggest players when it comes to performance. CAS plays a big part in OC'ing as .5 increase or decrease can be a world of difference and in general RAS to CAS the lower it is the higher your performance will be in most benchmarks. Other timings are important as well but they don't play big part as the previous two I mentioned.

Also you shouldn't have any problem running 1T with your CPU because RAM Manf like to play it safe by rating their RAM as 2T especially with high density RAM like 2GB kits since there are still people that are running on older version CPU's which have outdated memory controllers (AMD's have built in memory controller in their CPU's instead of using one on the north bridge) which can't handle more then 1GB of RAM without switching to 2T command rate.
 
OP
P

prophetx2

New Member
Joined
Dec 7, 2005
RedDragonXXX said:
Freq does make up for loose timings, but not as much in vice versa.

Look at it this way; 300MHz TCCD chips running at 2.5-4-4-8 timings will perform about the same as 260MHz UTT at 2-2-2-5 timings, but if I were to up timings on UTT's with same freq to 2-3-2-5 then it's a different story.

CAS latency and RAS to CAS are the biggest players when it comes to performance. CAS plays a big part in OC'ing as .5 increase or decrease can be a world of difference and in general RAS to CAS the lower it is the higher your performance will be in most benchmarks. Other timings are important as well but they don't play big part as the previous two I mentioned.

Also you shouldn't have any problem running 1T with your CPU because RAM Manf like to play it safe by rating their RAM as 2T especially with high density RAM like 2GB kits since there are still people that are running on older version CPU's which have outdated memory controllers (AMD's have built in memory controller in their CPU's instead of using one on the north bridge) which can't handle more then 1GB of RAM without switching to 2T command rate.

wow thanks for clearing things up! I had no clue the timings would make that much of a difference! Thanks a bunch, can't wait until I get to try some of these things out!
 
Dragon hit the nail on the head.

But! if you want to know were to start with your ram, go to the DRAM stable settings thread, it should give you a generaly idea of what your 'RAM' can do. That doesnt mean it will do what others can, as motherboard, CPU, PSU, etc, all have an important role in what you can achieve.