Question about ram

[ABCDEF(Gay)HIJKLMNO(Buddy)]

Currently I have 8gb(2x4gb) of ram in my pc. I would like to install another 8gb(2x4gb) but my type of ram is no longer available in shop where I bought it or anywhere else, so I have to buy used. My main concerns are small differences in ram characteristics. I would really appreciate if somebody could explain to me what are these differences and will it be ok if i combine these modules?

First picture is my ram and as you can see it is completely identical. Second and third pictures are modules that I could buy.

Module on third picture have different latency than mine and I've read somewhere that modules with different latency should not be combined. Is this true?

But module on second picture is almost identical except for label B1. What does this label represent?

Thank You in advance.

[GreezyJeezy]

timings need to be the same 

[ABCDEF(Gay)HIJKLMNO(Buddy)]

Ok. So, module on third picture is out. What about module on second picture?

[ExozeGD]

this shouldn't make a big difference because it will just run at the speed of the slowest stick. my friend is using mixed ram from i think even different companies

[Nord]

Mixing RAM is always a hit & miss.

 

Out of my own experience:

some RAM will work even if they have different timings or are from a different brand and sometimes others will not work even though they are basically identically.

Sometimes when you pair "different" RAM the performance impact will only be noticable in syntethic benchmarks, other times it will make your system bluescreen or just cause crashes, laggs, freezes or just lower performance.

 

If you have a proper motherboard, it should basically take care of the incompatibilities between the sticks you put in itself and make them work with each other, which is usually achieved by downclocking them.

Generally its not advised to mix RAM, not because it does not work but because it is never 100% that they will or wont work together. Even if the system boots up with them, you never know if they are 100% stable under every workload and like I said, as they usualy get downclocked to the slowest RAM, you also never know how much of a performance hit you might take untill you test it.

Furthermore RAM testing is the most time consuming thing you could do on a PC, for 8GB you should easily plan 8 - 12hours testing in DOS mode basically, double that for 16GB and so forth.

 

The 3rd RAM, with the B1, I'd give a good chance of working with the ones you allready have, the 4th will make your others slower, if it even works.