Question Will Using 3 x 8GB (Single Channel) Be A Lot Slower Than 2 x 8GB (Dual Channel) ?

[worstalentscout]

hi,

i have a ASRock B450M Steel Legend motherboard............i don't play games at all...........using 2 x 8GB RAM (normal Crucial ones) at the moment but having Chrome browser seems to reach 70-80% memory usage easily......if i were to add another 8GB RAM (same model).........would it slow down a lot ??!!

at one time, i had to use 1 x 8GB RAM in the same PC and it was a lot slower..........so worried that using 3 x 8GB RAM would be a lot slower than 2 x 8GB RAM.......

many thanks for any advice in advance...........

 

[Lutfij]

using 2 x 8GB RAM (normal Crucial ones
That doesn't state much, please read off the stickered info on the side of the ram sticks. What BIOS version are you on for your motherboard?

Always look at ram upgrades as you with a pair of shoes or a tyre change. You need to buy a set. Why not just get a larger kit of ram, i.e, 2x16GB sticks of ram? There are a number of options around. Where are you located?

If you don't tax your platform with games nor do you do any form of productivity work, then you can add an identical stick of ram as the other two you have in your system.

 

[boju]

Info here about running asymmetric dual-channel.

https://www.makeuseof.com/what-is-ram-flex-mode-how-does-it-work/#:~:text=Yes%2C%20AMD%20hardware%20also%20supports,dual%2Dchannel%20for%20AMD%20hardware.

As fussy as Amd can be about memory, if you manage to get three going, might be troublesome trying to run them at XMP speeds. Dual channel is one aspec of performance but so is XMP. Both are important for performance, I'd say more so for XMP. If XMP is difficult to enable with three dimms then settle for just the two.

 

[BFG-9000]

The simple answer is you can't run three sticks in single-channel, because you have two slots for each channel. You can run two sticks in single channel if you put them into the "wrong" slots but the third slot will always be the other channel.

Intel has had Flex memory technology since 2004 and you have AMD's equivalent asymmetric dual-channel. Therefore with three 8GB sticks installed, the first 16GB will run in dual-channel and the last 8GB in single-channel, which still beats swapping.

Whether you buy one stick or a pair to go with your current memory, it would still be mismatched and may not run at full speed or timings, or require more voltage than advertised.

 

[worstalentscout]

using 2 x 8GB RAM (normal Crucial ones
That doesn't state much, please read off the stickered info on the side of the ram sticks. What BIOS version are you on for your motherboard?

Always look at ram upgrades as you with a pair of shoes or a tyre change. You need to buy a set. Why not just get a larger kit of ram, i.e, 2x16GB sticks of ram? There are a number of options around. Where are you located?

If you don't tax your platform with games nor do you do any form of productivity work, then you can add an identical stick of ram as the other two you have in your system.

Info here about running asymmetric dual-channel.

https://www.makeuseof.com/what-is-ram-flex-mode-how-does-it-work/#:~:text=Yes%2C%20AMD%20hardware%20also%20supports,dual%2Dchannel%20for%20AMD%20hardware.

As fussy as Amd can be about memory, if you manage to get three going, might be troublesome trying to run them at XMP speeds. Dual channel is one aspec of performance but so is XMP. Both are important for performance, I'd say more so for XMP. If XMP is difficult to enable with three dimms then settle for just the two.

The simple answer is you can't run three sticks in single-channel, because you have two slots for each channel. You can run two sticks in single channel if you put them into the "wrong" slots but the third slot will always be the other channel.

Intel has had Flex memory technology since 2004 and you have AMD's equivalent asymmetric dual-channel. Therefore with three 8GB sticks installed, the first 16GB will run in dual-channel and the last 8GB in single-channel, which still beats swapping.

Whether you buy one stick or a pair to go with your current memory, it would still be mismatched and may not run at full speed or timings, or require more voltage than advertised.

many thanks for the info and advice................i ordered the 8GB RAM just now due to a sale.........so should i insert the 3rd stick in between the other 2 sticks ?

 

[boju]

many thanks for the info and advice................i ordered the 8GB RAM just now due to a sale.........so should i insert the 3rd stick in between the other 2 sticks ?

We have just informed you what might happen, XMP maybe? It's up to you to find out now. I wouldn't have bothered with the third stick imo.

 

[worstalentscout]

We have just informed you what might happen, XMP maybe? It's up to you to find out now. I wouldn't have bothered with the third stick imo.

i don't play games so both 8GB RUN at 2666mhz at the moment..........i do have several Chrome windows open with many tabs and my memory usage will go just over 90%........so i thought better to grab another 8GB.............the price was good too

 

[boju]

i don't play games so both 8GB RUN at 2666mhz at the moment..........i do have several Chrome windows open with many tabs and my memory usage will go just over 90%........so i thought better to grab another 8GB.............the price was good too

Capacity will help with that but to think XMP is mainly for gaming? No. Ryzen performance relies on memory performance so without XMP there's a significant chunk of cpu processing power left on the table. Processing powa to crunch more tabs quicker.

 

[BFG-9000]

It's not like the manual shows how to put RAM in an unsupported configuration. Just put it in one way and if it doesn't work, try the other way.

You have full manual controls of timings and voltages, so should be able to get it working even if not everything will end up at exactly the XMP settings. XMP for Intel and AMD's version EXPO are just ways to store timing and voltage presets in the memory module's SPD for automatic optimization by just ticking a setting in the BIOS--this is not the default because such settings might not always work, so safe settings are used as default instead to make sure you can always get into the BIOS after a CMOS clear. If you look up the spec sheet for the memory, all of those should be listed.

Using an unsupported memory configuration is real overclocking and it's up to you to test stability with each step. Yes, you could try starting with the XMP settings whether automatic or manually entered, and adjust as needed to get a stable system. As with most memory overclocking on AMD, using the latest motherboard BIOS with newest AGESA in it should give you the best compatibility and least problems.