[SOLVED] Does the speed of RAM get doubled with two sticks?

[Jacob 51]

Imagine one stick runs at 1600 MHZ and we put in another stick of RAM which runs at 1600 MHZ too.
Will it run at 3200 MHZ?
OR
Will one provide 800 MHZ and the other 800MHZ too?

 

[BFG-9000]

If you put two cars on a freeway instead of one, does that double their speed?

I suppose it depends on what you mean by speed. If you are thinking about passengers moved per hour, then yes. Most people would consider though the speed of the cars themselves as that's what affects the time it takes the first passenger to arrive--in which case the answer would be no.

A 747 filled with hard drives has a very high bandwidth, higher than any available internet connection. But the latency of going coast-to-coast to deliver that first bit is over 6 hours. Two 747s would not change that.

At 1600MHz one bit takes 0.000000000625 seconds to arrive. With two sticks at 1600MHz it would take exactly the same amount of time, but could deliver two bits

 

[Quanticriver]

Imagine one stick runs at 1600 MHZ and we put in another stick of RAM which runs at 1600 MHZ too.
Will it run at 3200 MHZ?
OR
Will one provide 800 MHZ and the other 800MHZ too?

Jacob

ram speeds do not stack

in fact if you pair a slower (compatible ) ram module with a faster one it will work on the slowest speed

going from your example;

a 1333 and a 1600 ram stick will only work at 1333hz

 

[JWNoctis]

Neither.

Keeping it simple - Presuming that the CPU supports dual-channel memory, and that the modules are installed into the correct slots on the motherboard, then the processor would be able to access both sticks more or less in parallel, for an effective speed of 2x 1600MHz.

Please, read up on multi-channel memory architecture for a more detailed explanation.

 

[CountMike]

"Speed" as in frequency ?, no it doesn't.
"Speed" as in memory performance can help but still not double.

 

[JWNoctis]

"Speed" as in frequency ?, no it doesn't.
"Speed" as in memory performance can help but still not double.

True enough.

Theoretical bandwidth may double. Actual bandwidth and user experience in the form of framerate and responsiveness, much less.

 

[CountMike]

True enough.

Theoretical bandwidth may double. Actual bandwidth and user experience in the form of framerate and responsiveness, much less.

Generally it's up to OS and SW how to use memory and it's performance but it's influence on overall performance is relatively small and may mean only couple of FPS in a game for instance. That specially true in case of DDR3 and earlier because spread between slowest and fastest RAM is much lower than with DDR4.
So small difference didn't incite OS, game and program developers to optimize for performance and quantity counted for much more.

 

[BFG-9000]

If you put two cars on a freeway instead of one, does that double their speed?

I suppose it depends on what you mean by speed. If you are thinking about passengers moved per hour, then yes. Most people would consider though the speed of the cars themselves as that's what affects the time it takes the first passenger to arrive--in which case the answer would be no.

A 747 filled with hard drives has a very high bandwidth, higher than any available internet connection. But the latency of going coast-to-coast to deliver that first bit is over 6 hours. Two 747s would not change that.

At 1600MHz one bit takes 0.000000000625 seconds to arrive. With two sticks at 1600MHz it would take exactly the same amount of time, but could deliver two bits