how much to memory timings affect performance?

eddyc · 17 Feb 2010 at 15:41

Hi all,

I have 4GB of OCZ obsidian running at 1600 Mhz (at least I think it is 1600 - it says 800 in cpu-z memory tab but you double that right? :confused:

) with 9-9-9-24 timings.

Would changing the timings improve performance?

What changes should I make?

I assume that I should use memtest to check if any changes have destabilised the ram?

pinki104 · 17 Feb 2010 at 15:42

i have been told timings arnt really that essential in ddr3 but i went with the tighter timings anyway just to be sure

Vertigo · 17 Feb 2010 at 20:57

Timings are just as important as outright speed with DDR3, within reason. You'll often be better off with the next lowest speed if it has tighter timings.

Worth a read: http://www.tomshardware.co.uk/phenom-ii-ddr3,review-31596-5.html

eddyc · 18 Feb 2010 at 01:08

Thanks for that link. Really interesting.

I think I will try reducing the timings a step or two just for the sake of it but to be honest it kind of sounds like it does not make all that much difference apart from in benchmark tests.

Since I have 9-9-9-24 I guess the next step is to try 8-8-8-22?

Cheers for all the help.

mymorph · 18 Feb 2010 at 08:26

ive tried tighter timings on my ddr2, made system less stable, tried looser timings too- still seemed to make system less stable?? :confused:

eddyc · 18 Feb 2010 at 12:20

Weird.

Do you have your memory over voltage settings in the bios running at the correct level. I only realised recently that this is not automatic. You have to find out from the manual what the correct setting is and then set the mobo to provide that.

My ram is running significantly under volted but it seems to be happy so I let it be :rolleyes:

mymorph · 19 Feb 2010 at 22:09

its running happy at the correct settings, so ive just left it alone.

Taziir · 20 Feb 2010 at 00:01

Sorry to add a noob question, but 8-8-8-12 is 'tighter' than 9-9-9-24 right?

One of my paired ram sticks has gone bad on auto settings (5-6-6-18, 1.8v) and stabilised at 7-6-6-18, 2.1v with increasing row cycle from 24 to 26.

Memtest reports no errors but will be RMA the pair soon, just want to understand the figures a little better.

Insanties_birth · 20 Feb 2010 at 18:44

Taziir said:
Sorry to add a noob question, but 8-8-8-12 is 'tighter' than 9-9-9-24 right?

One of my paired ram sticks has gone bad on auto settings (5-6-6-18, 1.8v) and stabilised at 7-6-6-18, 2.1v with increasing row cycle from 24 to 26.

Memtest reports no errors but will be RMA the pair soon, just want to understand the figures a little better.

Yes as the lower the timings the tighter it is between each timing period.

eddyc · 22 Feb 2010 at 10:11

I tried to take mine from 9-9-9-24 down to 8-8-8-22 and it failed. I only took the V up to 1.6 (the rated v of the sticks) though.

How well does ram deal with higher voltages than they are rated for?

Corasik · 22 Feb 2010 at 20:28

Each number represents how many clock cycles to wait for data in various operations and modes. In each case the less clock cycles spent waiting, the sooner the data is available to the cpu.

Latency is still important today, and will make a difference, but application design will come into play as well. Modern CPU's attempt to fill their cache's before data is actually required, and generally attempt to transfer large blocks of data (utilizing the memory bandwidth) as often as possible.

However in the event of a cache miss, the CPU will have to get the required data from ram, and then latency is everything, as the cache miss could potentially only require a small amount of data. Low latency ram will still make a system feel smoother in day to day use, even though benchmarks may only show a nominal improvement.