Single rank ram?

[BobThePCMaker]

Hi, could someone please explain to me, what is meant by this ram being 'single rank'? I assume it doesn't mean you only use one of the sticks??

 

Ballistix Sport LT BLS2K4G4D240FSB 8 GB Kit (4 GB x 2) (DDR4, 2400 MT/s, PC4-19200, CL16, Single Rank x8, DIMM, 288-Pin) Memory - Grey https://www.amazon.co.uk/dp/B00UFBZOLO/ref=cm_sw_r_cp_apa_i_SvXkDb1QZANKC

 

(New to this )

 

[WereCat]

 

[goto10]

single rank often happens when you buy a ram module that only has ram chips soldered on one side of the pcb

 

this os the wikipedia link explaining more detailed

 

https://en.wikipedia.org/wiki/Memory_rank

 

basically most ram kits like corsair lpx or similar kits have dual rank most times, only thpse ram modules without the metallic shield come single rank, but i bet there are exceptions

[kaldarash]

The short of it: single rank means RAM modules on 1 side, while dual rank has modules on both sides.

 

Dual rank can be slightly faster (1-5%), but if the single rank is a good price by comparison, there's no need to go with dual rank.

 

You can mix and match single and dual rank, but having said that, you'd be mixing and matching sticks and that in itself is not a good idea - but there are no problems other than the conventional wisdom of not mixing sticks.

[porina]

48 minutes ago, goto10 said:

basically most ram kits like corsair lpx or similar kits have dual rank most times, only thpse ram modules without the metallic shield come single rank, but i bet there are exceptions

Very wrong. In DDR4, all 4GB modules are single rank. Most if not all current 8GB modules are single rank. I have one relatively old kit that was dual rank. I only recently got my first 16GB modules recently, and they were dual rank. I would make the assumption that unless you're getting 16GB modules, it is almost certainly single rank.

 

If you want to check, CPU-Z often is able to report what rank modules are. For more detail you can also use Thaiphoon Burner.

 

13 minutes ago, kaldarash said:

The short of it: single rank means RAM modules on 1 side, while dual rank has modules on both sides.

In practice, yes. Technically is doesn't have to be related to the physical layout.

 

13 minutes ago, kaldarash said:

Dual rank can be slightly faster (1-5%), but if the single rank is a good price by comparison, there's no need to go with dual rank.

In practice you don't have much of a choice. It seems like all 8GB modules are single rank now. If anyone can confirm a 4GB or 8GB module that is currently sold and is dual rank, I would be very interested as I have an application that can see tens of % improvement from from having a dual rank kit of same speed and timings of single rank. I would add, having two single rank modules per channel (4 modules for dual channel system) seems to give the same benefit. I also need to add, the speedup for most things is not significant.

 

13 minutes ago, kaldarash said:

You can mix and match single and dual rank, but having said that, you'd be mixing and matching sticks and that in itself is not a good idea - but there are no problems other than the conventional wisdom of not mixing sticks.

It might not be optimal but it can still work. I have two mismatched 8GB modules in my laptop as I can't replace the factory supplied one. 2400 single rank + 2133 dual rank. It still works fine in dual channel mode at 2133, for better overall performance than a single module.