Can two identical ram sticks work in dual channel?

[MgR]

I want to upgrade my computer to 16 gb of ram. It currently has a single 8gb stick. My question is can i buy an exact same 8gb stick to have 16gb in dual channel? 

[WoodenMarker]

It usually works but sticks aren't guaranteed to work in configurations outside of pre-configured kits.

[Oshino Shinobu]

Yes, but it's not certain to work. Even if they're exactly the same model, if they're not bought as a kit that has been tested together, there's always a chance they may not work together. 

[SupaKomputa]

It will work, even with the non matching ones.

Dual Channel rules are not that strict.

If you have different speed, then the motherboard will automatically down-clock the fastest stick to match the lowest stick, so they can run together in dual channel mode.

10 years ago there's no memory sold in pair, but you're advised to buy the exact match to avoid incompatibilities (plus so you buy the memory from the same company $$$).

I never buy paired stick, and it always worked.

[MgR]

So if they don't work, is it mean that the system only recognize and run with one stick or the two stick but just not in dual channel? 

 

[SupaKomputa]

If they don't work, it will run in single channel mode. simple as that. you will still have the 16gb.

single channel vs dual channel is not night and day difference.

[MgR]

Thank you guys very much. I guess i'll try my luck then. 

[Oshino Shinobu]

9 hours ago, SupaKomputa said:

If they don't work, it will run in single channel mode. simple as that. you will still have the 16gb.

single channel vs dual channel is not night and day difference.

 

9 hours ago, MgR said:

So if they don't work, is it mean that the system only recognize and run with one stick or the two stick but just not in dual channel? 

 

It could be either. They may not run in dual channel, or they may not run together at all. If the specs are matched closely, the chances of them not working together are slim, but still there

[xAcid9]

Usually it will work, i'm currently using 4+4+8 and it's running in dual channel mode.

[airdeano]

4 minutes ago, xAcid9 said:

Usually it will work, i'm currently using 4+4+8 and it's running in dual channel mode.

the 4+4 is working in dual channel, but he +8 is still in single. so if any overflow moves to the +8 addresses you'll feel a system hitch/slowdown.

 

@MgR if you run intensive memory calcs, you might run into memory address issues. won't know until it happens.

[xAcid9]

12 minutes ago, airdeano said:

the 4+4 is working in dual channel, but he +8 is still in single. so if any overflow moves to the +8 addresses you'll feel a system hitch/slowdown.

 

@MgR if you run intensive memory calcs, you might run into memory address issues. won't know until it happens.

Anyway for me to check that?

[airdeano]

@xAcid9 the way the RAM slots are populated. otherwise no real software to 'check' on assignments. certain hitches or abnormalities would be the culprit.

[SupaKomputa]

1 hour ago, xAcid9 said:

Usually it will work, i'm currently using 4+4+8 and it's running in dual channel mode.

Wow, that's odd, how do you know it is running at dual channel?

What i know the slots must be even to have dual channel.

Any odd numbers will cancel the dual channel.

If two system are in one pc, the single channel will delay half of the data.

Doesn't make sense. But i maybe wrong.

[xAcid9]

49 minutes ago, airdeano said:

@xAcid9 the way the RAM slots are populated. otherwise no real software to 'check' on assignments. certain hitches or abnormalities would be the culprit.

That'll be hard to detect, haven't notice any anomalies so far. Aida mem bench show typical dual channel speed for me.

38 minutes ago, SupaKomputa said:

Wow, that's odd, how do you know it is running at dual channel?

What i know the slots must be even to have dual channel.

Any odd numbers will cancel the dual channel.

If two system are in one pc, the single channel will delay half of the data.

Doesn't make sense. But i maybe wrong.

It will run in asynchronous dual channel instead of typical synchronous dual channel i guess.

 

[Glenwing]

1 hour ago, SupaKomputa said:

Wow, that's odd, how do you know it is running at dual channel?

What i know the slots must be even to have dual channel.

Any odd numbers will cancel the dual channel.

If two system are in one pc, the single channel will delay half of the data.

Doesn't make sense. But i maybe wrong.

As long as the sticks within each channel are the same capacity, it can run in dual-channel.

 

https://www.intel.com/content/www/us/en/support/articles/000005657/boards-and-kits.html

 

Quote

Single-channel with three DIMMs

 

At boot, the memory configuration is detected and you might see this alert message:

Quote

Alert: Maximum memory performance is achieved with equal amounts of memory installed in each channel. Press any key to continue. 

With the DIMMs that are currently installed, the computer is set to single-channel mode, but it can be set to dual-channel mode. If you shut down and rearrange the DIMMs properly, you can establish dual-channel mode.

 

Dual-channel with three DIMMs
 

 

Rules to enable dual-channel mode

To achieve dual-channel mode, the following conditions must be met:

• Same memory size. Examples: 1 GB, 2 GB, 4 GB.
• Matched DIMM configuration in each channel.
• Matched in symmetrical memory slots.

Configurations that do not match the above conditions revert to single-channel mode. The following conditions do not need to be met:

• Same brand
• Same timing specifications
• Same speed (MHz)

The slowest DIMM module populated in the system decides memory channel speed.

 

[SupaKomputa]

nice video, but in that video still use 2 slots not 3.

i'm curious if this possible, can you post some screenshot to confirm the dual channel?

If this true then it would be much more easier to get dual channel without buying factory paired sticks.

 

7 minutes ago, Glenwing said:

As long as the sticks within each channel are the same capacity, it can run in dual-channel.

 

https://www.intel.com/content/www/us/en/support/articles/000005657/boards-and-kits.html

Yes, but the video confirm that you don't need to have the same capacity. Which is good news.

The problem is if 4x2 already in dual channel, slot 1 & 3, the third one still in single channel.

[Glenwing]

21 minutes ago, SupaKomputa said:

nice video, but in that video still use 2 slots not 3.

i'm curious if this possible, can you post some screenshot to confirm the dual channel?

If this true then it would be much more easier to get dual channel without buying factory paired sticks.

 

Yes, but the video confirm that you don't need to have the same capacity. Which is good news.

The problem is if 4x2 already in dual channel, slot 1 & 3, the third one still in single channel.

It might be different for AMD platforms.

 

I'm not sure what you mean. If you had 4x2 running in dual-channel mode and you added a third stick, it wouldn't run in single-channel mode all by itself on a dual-channel system. It would join one of the other 4 GB sticks and those two together would run in dual-channel with the last stick, or the whole thing would run in single-channel mode.