How does RAM frequency work?

[Alir]

My build: https://uk.pcpartpicker.com/list/PLwJm8

 

I am running Memtest86 5.01.

 

One of the lines says

Quote

RAM: 933 Mhz (DDR3-1866) - BCLK: 100

 

My RAM has a frequency of 1866. But I am curious as to whether it has made an error and thinks my RAM sticks have a frequency of 933. Is this how RAM frequency always works? That the advertised frequency is just the frequency of both sticks added together? So two sticks of 1600Mhz are in fact 800 each?

[Alir]

Also, as a side question.

 

My desktop currently has 4 RAM slots, with only two being used, 4GB each. Can I add two more sticks of the exact same model, just double in memory?

 

So would it be possible to have 2 4GB sticks and 2 8GB sticks? So in total I would have 24GB memory?

[adithyay328]

First q: IDK, maybe that's the clock speed without intel XMP or that's the clock of each stick, something similar to that, I think.

Second q: Be careful, as incompatibilities are common with those configs. I also have this scenario, except I have different speeds on each stick.

 

Cheers!

[TheRandomness]

DDR = Double data rate. 933*2 = 1866. 

[ARikozuM]

DDR = Double Data Rate

 

I recommend reading this and then returning with any questions that you'll need.

 

Wikipedia Link

[adithyay328]

2 minutes ago, TheRandomness said:

DDR = Double data rate. 933*2 = 1866. 

 

Just now, ARikozuM said:

DDR = Double Data Rate

 

I recommend reading this and then returning with any questions that you'll need.

 

Wikipedia Link

 

Oops, I forgot....uh oh....

[Alir]

29 minutes ago, Alir said:

Also, as a side question.

 

My desktop currently has 4 RAM slots, with only two being used, 4GB each. Can I add two more sticks of the exact same model, just double in memory?

 

So would it be possible to have 2 4GB sticks and 2 8GB sticks? So in total I would have 24GB memory?

 

27 minutes ago, adithyay328 said:

First q: IDK, maybe that's the clock speed without intel XMP or that's the clock of each stick, something similar to that, I think.

Second q: Be careful, as incompatibilities are common with those configs. I also have this scenario, except I have different speeds on each stick.

 

Cheers!

 

What kind of incompatibilities?

 

Surely it's just a matter of whether the OS will run or not?

[ARikozuM]

5 minutes ago, Alir said:

What kind of incompatibilities?

You can add 16GB to your current 8GB. Stick to the same voltage and speed for the least issues, though you shouldn't have any. If you're on a Z-chipset, you can mix speeds but the overall bandwidth or MHz will be the lowest of the pairs (or individual). CAS doesn't matter but I would suggest manually inputting the values through the BIOS.

[Alir]

22 hours ago, ARikozuM said:

You can add 16GB to your current 8GB. Stick to the same voltage and speed for the least issues, though you shouldn't have any. If you're on a Z-chipset, you can mix speeds but the overall bandwidth or MHz will be the lowest of the pairs (or individual). CAS doesn't matter but I would suggest manually inputting the values through the BIOS.

 

But if the model is exactly the same, just double the RAM, would that cause problems? Would I be fine with just popping them in and going on my way?

[ARikozuM]

3 minutes ago, Alir said:

 

But if the model is exactly the same, just double the RAM, would that cause problems? Would I be fine with just popping them in and going on my way?

You should be fine. Most people run into issues running RAM speeds that the board doesn't support.