Ram Timing

Simon_89 · 17 Jun 2012 at 14:17

Could anyone explain to me exactly how ram timing affects the system? And an example of bad timing and good timing.

Just one of those things that I can't make sense of :rolleyes:

Cheers

Simon_89 · 18 Jun 2012 at 10:09

Anyone?

Yaayuh! · 18 Jun 2012 at 10:25

Without going into too much detail; they are the time (Clock Cycles) that the memory chip delays whilst doing something. The higher the number the longer the delay, the lower the number the quicker the memory controller/CPU can have access the data.

The higher the frequency the higher the timings will generally be.

e.g. (Generalisation of timings that can be found vs frequency)
1600MHz -- 8,8,8,24
1866MHz -- 9,9,9,24
2000MHZ -- 10,10,10,28
2133MHz -- 10,11,11,28

To find out more there are loads of articles and forum posts on memory timings.

http://www.overclock.net/t/26706/info-ram-timings-for-dummies

8 Pack · 18 Jun 2012 at 11:22

2440 mhz 7-11-7-28

and on X79 not Ivy

8 Pack · 18 Jun 2012 at 11:34

Simon_89 said:
Anyone?

Basically well tuned RAM increases the performance of the system. It depends on applications your running to how much. In general for things such as gaming its not noticable though without synthetic benchmarks. Not like going from mechanical HDD to SSD for example or mid range to high range graphics card.

Instances such as video coding get a healthy boost though.

Simon_89 · 18 Jun 2012 at 19:01

The higher the number the longer the delay, the lower the number the quicker the memory controller/CPU can have access the data.

The higher the frequency the higher the timings will generally be.

e.g. (Generalisation of timings that can be found vs frequency)
1600MHz -- 8,8,8,24
1866MHz -- 9,9,9,24
2000MHZ -- 10,10,10,28
2133MHz -- 10,11,11,28

If that's the case why is it the higher the Mhz the higher the number, so that must mean it's slower but due to the higher speed it can compensate for it? Am I sounding on the right lines or talking complete rubbish?

Justintime · 18 Jun 2012 at 19:22

More or less along the right lines, optimally you'd want the lowest timings and the highest MHz but RAM chips are under more 'pressure' at the higher MHz and the lower timing will usually not work or be unstable at normal operating voltage, would be lovely to have some CAS 7 7 7 24 memory operating at 2133MHz

Yaayuh! · 19 Jun 2012 at 07:25

Simon_89 said:
If that's the case why is it the higher the Mhz the higher the number, so that must mean it's slower but due to the higher speed it can compensate for it? Am I sounding on the right lines or talking complete rubbish?

The higher the frequency, the more bandwidth is available but due to this more delay is required to keep it stable and provide that bandwidth.

Timings deal with latency (think of it as a ping time on a network connection but for your RAM)
Frequency is related to bandwidth (think I this as your internet connection speed but for your RAM)

To get the most out of your RAM you need to find a middle ground, the highest frequency with satisfactory timings. This can all be benchmarked to show latency and bandwidth and tuned to find the sweet spot.