CAS Latency , MHZ and Mushkin

[ExpertLayman]

Hello can someone tell me which of these memory cards is best and why. The prices are about the same:

Mushkin 6GB (3x2GB) DDR3 PC3-12800 6-8-6-24 Redline Ridgeback - 998970

Capacity 6GB (3x2GB)

CAS latency 6-8-6-24

Memory speed DDR3-1600Mhz (PC3 12800)

Test voltage 1.65v

Warranty Limited Lifetime Warranty

Mushkin 6GB (3x2GB) DDR3 PC3-16000 8-10-8-27 Radioactive - 998966

Capacity 6GB (3 x 2GB)

CAS latency 8-10-8-27

Memory speed DDR3 2000Mhz (PC3 16000)

Test voltage 1.65v

Warranty Limited Lifetime Warranty

My gut instinct tells me to go with the lower latency (Redline Ridgeback).

A few more question:

1. Does it matter if I choose buffer and unbuffered RAM?
2. Do you think I need ECC if I am into video/photo editing and 3D modelling. I know I don't need to worry about it in games.
3. And the final question can someone explain where the equations and number are coming from and how I can measure them to figure out was best from the following:

PC-4200 -> DDR-533 -> 266MHz base frequency

266MHz = 266 million cycles per second -> 3.76 x 10-9 sec per cycle (3.76 ns)

​

CL 3 = 3 x 3.76 ns = 11.28 ns

CL 4 = 4 x 3.76 ns = 15.04 ns

CL 5 = 5 x 3.76 ns = 18.80 ns

Taken from : How memory frequency affects latency - Tighter timings vs. Higher speeds?

Second example

• CAS Latency for DDR3-800 6-6-6-15 = 6 / 100 MHz = 6*10**-8 seconds
• CAS Latency for DDR3-1333 9-9-9-24 = 9 / 166 MHz = 5.4*10**-8 seconds

Taken from: Understanding Memory Timings

I've read them several times and I still don't understand where the numbers are coming from.In both cases the one with high speeds is the better option when moving large amounts of data. And considering I am going into 3d modelling and video/photo editing, I expect large amount of memory usage.

I would really appreciate an explanation of the articles equations.

Thanks