Memory question on SPD speed

[brighttail]

I'm looking at two different memory kits.  Both are 3200mhz rated with 16,18,18,36 timings.  They are exactly the same in total memory, both 32 gb but one kit is 80 dollars higher than the other.  Looking into the specs the one differences is one kit is rated at 2166 SPD with timings 15, 15, 15, 36 and the other is rated 2666 SPD with timings 18, 18, 18, 43.

 

This is where I'm confused because both are rated at 3200Mhz but the SPD's are different.  Does the higher SPD mean it can be overclocked more?  I guess the other difference is that the 2133 SPD says nothing about Ryzen but the 2666 SPD version says it is Ryzen ready.  I'm trying to figure out what is the difference between the two that would cause the manufacture to charge an additional $80 for the higher SPD.  Is it because it is Ryzen speced? Is it because the SPD is higher thus easier to obtain more stable overclocks or at least tighter timings?  Help?  And thanks.

[Jurrunio]

means nothing. Usually the first 3 are JEDEC specs while the 4th represents what they are binned for. Passing JEDEC specs are the minimal requirements

[brighttail]

7 minutes ago, Jurrunio said:

means nothing. Usually the first 3 are JEDEC specs while the 4th represents what they are binned for. Passing JEDEC specs are the minimal requirements

That is what I was figuring but if one has a baseline of 2133 MHZ and the other has a baseline of 2666 MHZ, then they are just running on different clock cycles? It is just weird that one is 80 bux more....I'm wondering if it has to do with the origin of the memory chips.  Corsair CMT32GMX4MAc3200C16 vs Corsair CMT32GMX4MAz3200C16 .  That C vs Z .. looks like a revision model. C being old XMS module and Z meaning Vengeance module .. I'm not sure the difference.  This makes more sense the C is the older version for x99 and such with the Z being the newer version for Ryzen.  I could get away with the C since I have a x299 model.

[Jurrunio]

13 minutes ago, brighttail said:

That is what I was figuring but if one has a baseline of 2133 MHZ and the other has a baseline of 2666 MHZ, then they are just running on different clock cycles?

clock cycles refer to the timings, so yes

 

14 minutes ago, brighttail said:

I'm wondering if it has to do with the origin of the memory chips. 

Usually no. Even if the chips are different models, their potential should be very similar. Otherwise the sticks wont have the same ratings.