Ram CAS vs speed

[D1Y4B]

Hi, I'm about to purchase some ddr3 8gb ram. I also want to overclock these too but I'm not sure about a few things.
Firstly, is it possible to overlcock ram as well as lower CAS latency.
I have ram cooling heatsinks so would overclock or reducing cas affect heat produced by ram?
Also I found a 8gb cl11 1600mhz ram for £35 and 8gb cl9 1600mhz for £45. Which one would be best for value.

 

[ShakedG]

1. Overclocking RAM is not recommended since it is unstable and the performance improvement is marginal at best.
2. Raising the speed or lowering the timings does not cause overheating, but instability. To make the system stable again you raise the RAM's voltage (not recommended, and should only be done carefully up to 1.65 V following the manufacturer's testing).
3. RAM clock speed vs latency really depends on what you are planning on doing. Assuming you're planning on playing video games a speed of over 1600-1866 MHz barely improves performance, while the timings do. Also a good way to compare two modules is by the formula CL/rate. The lower this is the faster your RAM will be.
4. If you are overclocking your CPU too, then be careful overclocking the RAM as it can cause further instability, and overheat your CPU's memory controller.
I used to have a table (that I found online) comparing timings vs clock rate, if I'll find it I'll link it here.
5. From CL11 to CL9 is a huge difference, so I would recommend paying the extra 10 pounds, especially if you want too overclock.

 

[Rookie_MIB]

The general rule of thumb for ram is take the frequency, and divide it by the CAS timing. This allows you to compare the relative speed of different sticks, even if they're of different frequencies and CAS ratings. So, to compare those two sticks:

1600mhz/11CAS = 145
1600mhz/9CAS = 177

A higher score means it's relatively faster. In this specific case, it would be approximately 22% faster, while from a cost perspective it's about 33% more expensive. Of course, only you can decide if it's worth it.

 

[Tradesman1]

The CL9 1600 is the better choice and may allow OCing - trying to OC the other(CL11) would prob mean CL12 min at 1866 which isn't worth it. 1600 CL9 is basically the entry level for DRAM these days, so if you want to try OCing it, it's a decent choice pricewise

 

[D1Y4B]

Actually the ddr3 1600 cas11 for £35 I found similar price with CAs6 1600mhz

 

[ShakedG]

Actually the ddr3 1600 cas11 for £35 I found similar price with CAs6 1600mhz

Where??? I myself am looking for new RAM modules and could not find 1600 CL6. Then again, I am looking at 2x8GB.