Memory Conversion

Anomaly1964

Platinum Member
Nov 21, 2010
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Is there some formula for knowing that DDR4-2666 is PC4-21300 or is it just something you memorize?
 

IntelUser2000

Elite Member
Oct 14, 2003
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Yes there's a formula.

System memory in Desktops and Laptops are 64-bits wide. 2666 in DDR4-2666 refers to the transfer speed in MegaTransfers/s(MT/s).

2666 MT/s x 64 bits x 8 bits/byte = 21,328MB/s or 21.3GB/s. That's how you get PC4-21300.
 

Anomaly1964

Platinum Member
Nov 21, 2010
2,465
8
81
Yes there's a formula.

System memory in Desktops and Laptops are 64-bits wide. 2666 in DDR4-2666 refers to the transfer speed in MegaTransfers/s(MT/s).

2666 MT/s x 64 bits x 8 bits/byte = 21,328MB/s or 21.3GB/s. That's how you get PC4-21300.

Shouldn't it be (2666x64)/8... ?
 

IntelUser2000

Elite Member
Oct 14, 2003
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Shouldn't it be (2666x64)/8... ?

You can make it simpler and do 2666 x 8 since you know 64 bits equal 8 bytes.

I guess it has to be,
2666 MT/s x 64 bits x byte/8 bits

But you get the idea how they got those numbers. It's not something that was randomly assigned.