there isnt really a correct way to tighten your timings, different methods work for different people and different systems. I don't see why you only want to lower your CAS Latency, a combination of all works best. To tighten the CAS latency just lower the timing by 1, if you manage to boot keep lowering by 1 until you fail to boot. Once you manage to boot with the lowest timing then run memtest to check if it is stable. You could go tighten the CAS even further by increasing voltage but I wouldn't recommend that.
In my opinion you should try a combination of all 4 timings. Try lowering the 1st and 3rd timings by one, if you manage to boot into windows then lower your 2nd timing as far as it can go without failing to boot. Now lower the 1st and 3rd timings again to as low as they can get with the 2nd timing tightened to the max. Once you are done with those you can now lower your 4th timing. The 4th timing should generally be the sum of the previous 3 timings, so say for example you managed to get timings of 7-7-7 for the first 3, then a good starting point would be 21 for the 4th value, although there is no guarantee.
Good luck, hope this helped!
On older memory DDR that would be correct.
on newer DDR3 I run 1:4 with a 200 base clock. That means the memory is running at 800x2 for DDR=1600.
I know real fuzzy math but it is what the memory companies market it as.
RAM defaults to 1333 CL9, this is the JEDEC "aka industry" standard. Your specific RAM has to perform according to JEDEC at worst, at best it can be much faster. Yours is faster as it is rated for 1600mhz CL9 at 1.5V. You need to manuall increase the speed to this rate.
The ratio should be the FSB-DRAM ratio. The FSB controls a lot of things, from CPU speed to RAM speed and North Bridge speed. Basically it's the basic clock speed of your system and everything is multiplied by that.
It's possible your mobo will show the "data rate" instead of the "double data rate" (DDR). So the data rate would be 800, and since DDR3 means double data rate, then it's actual speed is 1600mhz. In a similar way, GDDR5 memory on a graphics card has a quad data rate, so 1200mhz GDDR5 is actually running at 4800mhz effective.
Thanks wolfram. I was confused because I have never had 4 sticks of ram and thought by having the 4 that meant 4x4=1600mhz. I will go in and set it. My mobo says I can set it at ddr3 800, ddr3 1333, ddr3 1600, etc. I will set ddr3 1600mhz.
You're fine. I don't think the 1:1 ratio has been relevant for a while now since it's almost impossible to get your FSB that high. In the past the FSB could do 400 or higher so you were able to get 1:1 FSB-DRAM ratio with DDR and DDR2.