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lukasz74nj

macrumors member
Original poster
Oct 19, 2012
35
1
I ordered a new iMac 2020 and want to upgrade the memory. I'm considering these 3:

1) Samsung 2 x 32GB DDR4 2666 (M471A4G43MB1-CTD00) - $240

1598066441926.png


2) Crucial 2 x 32GB DDR4 2666 (CT32G4S266M) - $320

CAS Latency: 19

3) OWC 2 x 32GB (kit) 2666MHZ DDR4 SO-DIMM PC4-21300 - $309

CAS Latency: not published

I leaning towards #1 because of the price, however I don't understand what is CL from the spec, i.e. is it 13.75? How about OWC?

Which one do you recommend? Thanks.
 
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lukasz74nj

macrumors member
Original poster
Oct 19, 2012
35
1
I know what is the definition of CAS latency, I was asking about CL for #1 and #3 in order to determine which model to choose.
 

The_Lord_of_Apple

macrumors regular
Jun 19, 2020
107
92
you are splitting hair!!! Is it going to make a difference what the CL value for each of the aforementioned RAM is for what you do? Just buy whichever one you can get your hands. For me it has always been and will be OWC.
 

SS2

macrumors newbie
Nov 29, 2020
3
0
Hello, I'm upgrading RAM on the same model iMac (2020, 27"). Trying to decide between Crucial and OWC. Anyone know why the B&H page suggests using OWC for Macs? Please see the bottom of this:


Secondly, any concerns about buying Crucial or OWC memory on Amazon Prime?
 

wilberforce

macrumors 65816
Aug 15, 2020
1,409
1,303
SF Bay Area
Hello, I'm upgrading RAM on the same model iMac (2020, 27"). Trying to decide between Crucial and OWC. Anyone know why the B&H page suggests using OWC for Macs? Please see the bottom of this:


Secondly, any concerns about buying Crucial or OWC memory on Amazon Prime?
Different people recommend different things. B&H may have a vested interest in selling OWC over Crucial, or perhaps they get less returns. Who knows. Without them explaining why, it just creates FUD. There is nothing wrong with Crucial, in fact it has an excellent reputation.
Amazon Prime is an excellent way to purchase it. That is what I and many others did.
 
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SS2

macrumors newbie
Nov 29, 2020
3
0
Thanks for the quick response. Just purchased Crucial from a seller called CalvinNHobbes on Amazon. (Prime didn't offer the specific model). Fingers crossed.
 

wilberforce

macrumors 65816
Aug 15, 2020
1,409
1,303
SF Bay Area
Thanks for the quick response. Just purchased Crucial from a seller called CalvinNHobbes on Amazon. (Prime didn't offer the specific model). Fingers crossed.
Just checking because your link was for only a single module: you are buying matched pairs, right?
 

wilberforce

macrumors 65816
Aug 15, 2020
1,409
1,303
SF Bay Area
Thanks for asking... i bought this item which has 2 x 16GB: https://www.amazon.com/gp/product/B071H38422/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Is that a matched pair as in built from the same semiconductor wafer or matched as in the same model?
What you bought is correct - a pair of DIMMs - i.e. matched part numbers.

I was concerned, because the link in your first post was for a single 32GB DIMM. Some people are not aware that you need to install them in pairs, one in each channel, else the RAM transfer speed is effectively halved.

Also, and you may already know this: for the 2020 iMac, do not install the 8GB Apple RAM along with the 32GB Crucial RAM. Mismatched DIMM sizes just degrade the RAM speed/performance (for only the 2020 iMac). Just leave the 8GB Apple RAM out.
 
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