what is the diffrence between these Rams 2GB 1Rx8 PC3 and 2GB 2Rx8 PC3?and which one is better and recommended?

[becauseisherenow]

I have optiplex 780 (Dell 200DY Optiplex 780 Motherboard)
which one is recommended and better ?
what is the diffrence in performance?

nt:I use 2GB 2Rx8 PC3

 

[Chicano]

This thread answers your questions partially. Which is better is the 2Rx8... your motherboard probably supports both types of RAM but you already have the better and recommended type.
http://www.tomshardware.com/answers/id-2644651/ram-1rx8-2rx8.html

 

[becauseisherenow]

what about this topic?
Beside speaking of performance generally Single Rank Memory is faster than Dual Rank Memory, in laymen’s terms when a computer accesses Single Rank Memory it only has to go around the track once, where as Dual Rank it would have to go around the track twice.[2]
https://www.oempcworld.com/support/singlevsdualram.html

 

[becauseisherenow]

Then is is faster than 2rX8?

 

[Pinhedd]

I have optiplex 780 (Dell 200DY Optiplex 780 Motherboard)
which one is recommended and better ?
what is the diffrence in performance?

nt:I use 2GB 2Rx8 PC3

1R and 2R denote the number of ranks per DIMM. Each rank is a set of DRAM chips that share a common chip select. For a given channel, only one rank can be selected at a time. There is a limit to the number of ranks that can be installed on a channel before buffering becomes necessary. For consumer motherboards that do not support buffering, the limit is 4 ranks per channel. Consumer motherboards have at most 2 DIMM slots per channel, and consumer DIMMs have at most 2 ranks per DIMM, so its hard to violate this limitation unintentionally.

An 8GiB 2R DIMM is identical in configuration to two 4GiB 1R DIMMs. However, using the 8GiB 2R DIMM leaves room for a second DIMM.

From a performance perspective it is preferable to have the maximum number of ranks installed. This means that 2x 2R DIMMs should be used whenever possible. 1R DIMMs are only viable to the extremely budget conscious.