I have 16Gb of DDR4-2666 RAM installed on two of four slots.

If I wanted to increase to 32Gb would it be better to buy 2 x 8Gb Sticks of DDR4-2666 and put those in the remaining two slots or buy 2 X 16Gb Sticks of DDR4-2666?

will the memory work just as well over 4 sticks as 2?

I am not sure how to find out if it is possible to use 3000mhz or higher sticks, I have looked in Bios (American Megatrends R01-80) but cannot see a way to increase it

 

Buy matching RAM. If I were doing this I would be buying 2x16 sticks of the fastest stuff with the best timings that I could afford and that was appropriate for my CPU and MOBO combo and taking the old stuff out. I wouldn't be buying another two sticks and adding it to what I already had. Even if you get the same speed with the same timings you may still run into trouble.

Trying to get mismatched sticks to work is just not something I'm prepared to waste time on anymore.

There are benefits and disadvantages to running both 4 sticks and 2 sticks but for most this is really not worth worrying about but 2 sticks is easier to get running faster and tends to be more stable and it has 2 less componants to go wrong in your machine. Like I said, I would be buying 2x16 of the best stuff I could afford.

1 hour ago, Tezbedz said:

I have 16Gb of DDR4-2666 RAM installed on two of four slots.

If I wanted to increase to 32Gb would it be better to buy 2 x 8Gb Sticks of DDR4-2666 and put those in the remaining two slots or buy 2 X 16Gb Sticks of DDR4-2666?

will the memory work just as well over 4 sticks as 2?

I am not sure how to find out if it is possible to use 3000mhz or higher sticks, I have looked in Bios (American Megatrends R01-80) but cannot see a way to increase it

 

 

In theory, if you're pushing the overclock, two works better than four.

Kits are sold as two sticks or  four for a reason. They are matched. If you buy a second kit comprising two sticks it often does work, but from time to time you can have issues. 

Edited March 23, 20215 yr by martin-w

Go for a kit of two matched 16GB sticks, you'll save yourself a lot of trouble. Trying to get four (even theoretically identical) sticks to work together can be a PITA...

Edited March 23, 20215 yr by tymk

You might have trouble finding stuff to match your existing RAM. Theoretically different brands of RAM with the exact same specs will work alongside one another but sometimes if you do that, they just don't like one another, so it's usually better to go for the exact same stuff if you can. You should be able to find out what RAM speeds your motherboard will support by looking up the specs of the board on the manufacturer's website or in the motherboard's instruction booklet, or failing that you can download and run the (free) CPU-Z which can be found here.

Theoretically, two RAM sticks is faster than four, and for a reason which you might initially find hard to believe: The closer your RAM sticks are physically to the CPU, the faster it will work, which sounds bizarre, but it is true, and that's because the electrical signals between the two components have less distance to travel down the wires. Now you might think this wouldn't matter when electrons travel at 186,000 miles per second, but if you consider that an Intel i7 processor is capable of handling 320,440 million instructions per second when running at 3.5 GHz, anything which can speed up that amount of journeys does actually make a difference overall in how fast it can get things done in the same way that if you could shave one second off a repetitive ten second process on a production line, then by the end of a day, you'd have saved a fair bit of time and have been able to make more components. This is exactly why computers have traditionally been made faster by making them smaller.

17 hours ago, Chock said:

 

Theoretically, two RAM sticks is faster than four, and for a reason which you might initially find hard to believe: The closer your RAM sticks are physically to the CPU, the faster it will work, which sounds bizarre, but it is true, and that's because the electrical signals between the two components have less distance to travel down the wires. 

 

It's not as simple as that. Depends on the topology. And it's about strain on the memory controller and "noise" rather than how far our electrons have to travel.

In fact, with a T-topology 4 modules can be faster in some games, otherwise it makes no difference.

The issues can arise with overclocking and can hold back high overclocks in some cases. Again, due to the strain on the memory controller and noise, not because electrons are slower.

 

To sum up, T-topology is best for stability with 4 modules and daisy chain topology is best for max overclock with two sticks.

It's not a huge impact though. If you do run 4 sticks and a high overclock, you may just need a slight increse in voltage.

Edited March 24, 20215 yr by martin-w

18 hours ago, Chock said:

 Now you might think this wouldn't matter when electrons travel at 186,000 miles per second, but if you consider that an Intel i7 processor is capable of handling 320,440 million instructions per second 

 

Actually that's an interesting concept. Electrons don't move at the speed of light through a conductor.

If we imagine a conductor, let's say basic 0.5 mm, carrying 5 amps, the drft velocity of the electrons is only one millimetre in one second. Its the wave that travels faster, the propagation of the electric field that's important.

And in a CPU, nope, it's not at the speed of light. It's slow. And the wave is two thirds of light speed.

 

 

Edited March 24, 20215 yr by martin-w