Memory timings in CPU-Z : Memory and SPD tab discrepancy – What do they mean

There are a lot of detailed explanations about this on overclocking forums as well as hardware review sites.

A very basic answer is that each number represents the number of cycles it takes before the memory can perform a given internal action. Generally, lower is better, however, it's not always true, as the separate numbers have an effect on each other.

You can think of this as basically a measure of how "quick" the memory is, as opposed to how "fast" it is. It's basically the delay before actions can get started.

Because the numbers measure clock cycles, remember that lower timings don't necessarily mean faster access times. Memory running at 100 MHz with a timing of 2-2-2-5 will have effectively slower timings than memory running at 400 MHz with a timing of 5-5-5-15 for example (even though it takes 5 clocks rather than 2 clocks, it cycles 4x faster).

Overall don't worry about it too much. Frankly, you probably are never going to notice the difference between different timings. The only reason you'd want to worry about it is if you are a benchmarking/overclocking enthusiast.

If you are just looking for a fast PC, and you aren't a big tweaker, you should buy well-reviewed, reliable RAM that comes at a good price. Invest that money you save by not buying low-timing memory in components that will make a bigger speed difference.

Most CPUs support a limited number of memory ranks.
Most consumer DIMMs are dual-rank (this is the most economical solution).

However there are also single rank DIMMs and quad-rank DIMMS. The difference betyween these is rather technical (and I had to look it up myself about a year ago), but it seems to come down to this:

• A CPU likes to have more memory channels to make things faster.
• This can be done with more DIMMs (seel dual-, triple- or even quad-channel CPU's), or by using one physical modules with 'sort-of' the content of two DIMMs on one stick.
  This is the rank.
• Most systems use dual channel dual rank memory. (two DIMMs, each with two ranks).
• A CPU can only drive a limited number of ranks. (Think of it as each rank draining the address bus a bit. More ranks is more draining. This limits how many ranks can be used, though sometimes more ranks can be used at a lower speed.

This (https://serverfault.com/questions/69612/dimms-single-vs-double-vs-quad-rank) might be interesting reading to grok the background.

But to answer your question:

My laptop is capable of supporting up to 32 GB.

That simple is not enough information. To answer it with any certainty we need something like:

• My laptop is capable of supporting up to 32 GB.
• In four DIMM sockets.
• With a maximum of X ranks
• And at a voltage of a.bc per DIMM.

My best guess it that it will work.

Depending on he chipset you may and up with:

8GB DIMM 4+4) First part of the 8GB DIMM Only in dual channel mode 4GB DIMM (4)

4GB DIMM (4) In dual channel mode 4GB DIMM (4)

Or with no dual channel mode at all for 12GB of your memory.

Note that the ranks at this point are mostly about 'will it work', and the channels are about 'will I get the 5% average speed increase from going dual-channel`.