What is dual/ quad channel ?

[Mark_Lawrence]

I have a motherboard that support dual channel memory architecture and it has 4 dimm slots? What does this mean? is it ok to buy 4 pcs or ram to achieve a total of let say...32gb? or just 2 pcs of 16gb of ram to achieve 32gb because its dual channel memory architecture?

Pleas explain it to me because its so confusing. Is it safe to say that when you have two dimm slots it will be called single channel, 4 dimms slots is dual channel and 8 slots is quad channel? Am i right?

 

[TJ Hooker]

I have a motherboard that support dual channel memory architecture and it has 4 dimm slots? What does this mean? is it ok to buy 4 pcs or ram to achieve a total of let say...32gb? or just 2 pcs of 16gb of ram to achieve 32gb because its dual channel memory architecture?

Dual channel basically means the memory controller can access both channels at the same time, increasing throughput. You can then have up to 2 DIMMs per channel.
It would be preferable to get 2x16GB rather than 4x8GB to get 32GB if you have a dual channel CPU/mobo. 4x8GB would still work, but in general as you add more sticks you can run into issues getting them to all work nicely together, especially with high-speed kits. Rule of thumb is that you want to get as few as sticks as possible while still a) achieving your desired total memory; and b) having at least 1 DIMM per channel.

Pleas explain it to me because its so confusing. Is it safe to say that when you have two dimm slots it will be called single channel 4 dimms slots is dual channel and 8 slots is quad channel? Am i right?

No, you can have mobos with 2 slots that are still dual channel, and 4 slot mobos that are quad channel.

 

[Aeacus]

To put it short:
single channel = 1 stick of RAM
dual channel = 2 sticks of RAM
triple channel = 3 sticks of RAM
quad channel = 4 sticks of RAM

Also a great explanation can be seen from here: https://www.youtube.com/watch?v=-D8fhsXqq4o

 

[TJ Hooker]

To put it short:
single channel = 1 stick of RAM
dual channel = 2 sticks of RAM
triple channel = 3 sticks of RAM
quad channel = 4 sticks of RAM

Well, having 4 sticks of RAM doesn't necessarily mean you're running in quad channel though.

 

[Aeacus]

Let me rephrase that.

If you buy a RAM kit then they are usually rated as follows:
single channel = 1 stick of RAM
dual channel = 2 sticks of RAM
triple channel = 3 sticks of RAM (can be achieved only when removing 1 RAM stick from quad set RAM)
quad channel = 4 sticks of RAM

But what you actually get will depend on MoBo.

 

[MeanMachine41]

Hi Mark

The more memory channels, the more memory bandwidth available to the CPU.
For each channel you need an individual stick of RAM. This also depends, of course, on the CPU. Core i7-4790K and Core i7-6700K support up to two channels, while chips such as the Core i7-5960X can support up to four channels.

Normally this doesn’t matter as there's not a great deal of difference however you wouldn’t buy an expensive X99 motherboard and pricey Core i7-5960X, then intentionally not use quad-channel memory performance by installing 2 DIMMs instead of four.

Here is a link that may help you understand: http://www.hardwaresecrets.com/everything-you-need-to-know-about-the-dual-triple-and-quad-channel-memory-architectures/

As I'm not sure what you have, list your system specs for better advice.

 

[Mark_Lawrence]

It would be preferable to get 2x16GB rather than 4x8GB to get 32GB if you have a dual channel CPU/mobo. 4x8GB would still work, but in general as you add more sticks you can run into issues getting them to all work nicely together, especially with high-speed kits. Rule of thumb is that you want to get as few as sticks as possible while still a) achieving your desired total memory; and b) having at least 1 DIMM per channel.

Why wouldn't it work nicely together? There are available rams sold in packs such as the corsair vengeance led 4x8gb=32 gb 3200mhz which are all identical, i doubt that they will not work synchronously...for what use they are selling it in bundles/ packs.

 

[Mark_Lawrence]

To put it short:
single channel = 1 stick of RAM
dual channel = 2 sticks of RAM
triple channel = 3 sticks of RAM
quad channel = 4 sticks of RAM

How about my motherboard, it has 4 dimm slots but is in dual channel memory architecture only? if i put it with 4 ram sticks, will my motherboard be 4 channel memory already?

 

[Mark_Lawrence]

Dual channel basically means the memory controller can access both channels at the same time, increasing throughput. You can then have up to 2 DIMMs per channel.
It would be preferable to get 2x16GB rather than 4x8GB to get 32GB if you have a dual channel CPU/mobo. 4x8GB would still work, but in general as you add more sticks you can run into issues getting them to all work nicely together, especially with high-speed kits. Rule of thumb is that you want to get as few as sticks as possible while still a) achieving your desired total memory; and b) having at least 1 DIMM per channel.

Why wouldn't it work nicely together? There are available rams sold in packs such as the corsair vengeance led 4x8gb=32 gb 3200mhz which are all identical, i doubt that they will not work synchronously...for what use they are selling it in kits/ bundles.

 

[Aeacus]

How about my motherboard, it has 4 dimm slots but is in dual channel memory architecture only? if i put it with 4 ram sticks, will my motherboard be 4 channel memory already?

Since your MoBo only supports dual channel and 2 sticks per channel, your RAM will run only in dual channel.

Here's how it works on MoBos with 4 RAM slots (i'll take my MSI Z170A Gaming M5 as an example).
Channels on my MoBo are as follows:
Slot #1 - Channel A
Slot #2 - Channel A
Slot #3 - Channel B
Slot #4 - Channel B

Currently, i have 2 sticks or RAM and they are seated in slot #1 and #3. This way, i have dual channel RAM since both sticks are in separate channel.
But if i were to put my 2 RAM sticks into slot #1 and #2, i have single channel, despite i having 2 sticks of RAM inside the MoBo.
And here is the reason why one should read the MoBo manual when inserting RAM when you have only 2 sticks and 4 slots.

If i were to buy 2nd set of RAM (2 sticks) and populate all my RAM slots, i'd still have my RAM running in dual channel since MoBo supports only 2 RAM channels.

 

[Mark_Lawrence]

How about my motherboard, it has 4 dimm slots but is in dual channel memory architecture only? if i put it with 4 ram sticks, will my motherboard be 4 channel memory already?

Since your MoBo only supports dual channel and 2 sticks per channel, your RAM will run only in dual channel.

Here's how it works on MoBos with 4 RAM slots (i'll take my MSI Z170A Gaming M5 as an example).
Channels on my MoBo are as follows:
Slot #1 - Channel A
Slot #2 - Channel A
Slot #3 - Channel B
Slot #4 - Channel B

Currently, i have 2 sticks or RAM and they are seated in slot #1 and #3. This way, i have dual channel RAM since both sticks are in separate channel.
But if i were to put my 2 RAM sticks into slot #1 and #2, i have single channel, despite i having 2 sticks of RAM inside the MoBo.
And here is the reason why one should read the MoBo manual when inserting RAM when you have only 2 sticks and 4 slots.

If i were to buy 2nd set of RAM (2 sticks) and populate all my RAM slots, i'd still have my RAM running in dual channel since MoBo supports only 2 RAM channels.

Thanks! now i know how these memory architectures work.

One question tho, is it true what tjhooker said that it is a rule of thumb to run fewer rams than an equivalent memory size of more rams? Because the more the ram count is, the hard it is to synchronize them thus causing issues?

 

[Mark_Lawrence]

Hi Mark

The more memory channels, the more memory bandwidth available to the CPU.
For each channel you need an individual stick of RAM. This also depends, of course, on the CPU. Core i7-4790K and Core i7-6700K support up to two channels, while chips such as the Core i7-5960X can support up to four channels.

Normally this doesn’t matter as there's not a great deal of difference however you wouldn’t buy an expensive X99 motherboard and pricey Core i7-5960X, then intentionally not use quad-channel memory performance by installing 2 DIMMs instead of four.

Here is a link that may help you understand: http://www.hardwaresecrets.com/everything-you-need-to-know-about-the-dual-triple-and-quad-channel-memory-architectures/

As I'm not sure what you have, list your system specs for better advice.

my motherboard is a maximus viii z170 formula and an i7 6700k

 

[TJ Hooker]

Dual channel basically means the memory controller can access both channels at the same time, increasing throughput. You can then have up to 2 DIMMs per channel.
It would be preferable to get 2x16GB rather than 4x8GB to get 32GB if you have a dual channel CPU/mobo. 4x8GB would still work, but in general as you add more sticks you can run into issues getting them to all work nicely together, especially with high-speed kits. Rule of thumb is that you want to get as few as sticks as possible while still a) achieving your desired total memory; and b) having at least 1 DIMM per channel.

Why wouldn't it work nicely together? There are available rams sold in packs such as the corsair vengeance led 4x8gb=32 gb 3200mhz which are all identical, i doubt that they will not work synchronously...for what use they are selling it in kits/ bundles.

If you buy them together as a kit then yes they should all work together (although if you watch the video Aeacus posted apparently running a quad channel kit on a dual channel mobo can occasionally have issues). However, for high speed kits, it sometimes not as easy as simply enabling the XMP profile to get them to run at their rated speeds. Running 4 sticks is harder on the memory controller than 2 sticks, so it's possible you might have more issues with 4 sticks than 2. I honestly don't know how likely you are to have issues, but seeing as there's no upside to getting a quad channel kit over a dual channel kit for a dual channel mobo (assuming you can get a dual channel kit with your desired capacity), why risk it?

It would also allow you to add another two sticks down the road if you need more memory, although mixing kits is always a bit of a gamble.

Edit: http://www.tomshardware.com/reviews/ddr-dram-myths,4155.html#p8

 

[MeanMachine41]

Hi Mark

The more memory channels, the more memory bandwidth available to the CPU.
For each channel you need an individual stick of RAM. This also depends, of course, on the CPU. Core i7-4790K and Core i7-6700K support up to two channels, while chips such as the Core i7-5960X can support up to four channels.

Normally this doesn’t matter as there's not a great deal of difference however you wouldn’t buy an expensive X99 motherboard and pricey Core i7-5960X, then intentionally not use quad-channel memory performance by installing 2 DIMMs instead of four.

Here is a link that may help you understand: http://www.hardwaresecrets.com/everything-you-need-to-know-about-the-dual-triple-and-quad-channel-memory-architectures/

As I'm not sure what you have, list your system specs for better advice.

my motherboard is a maximus viii z170 formula and an i7 6700k

The Z170 M8 Formula has Dual Channel Memory Architecture.
When choosing DIMMs, its best to consult the MB QVL listing for tested DIMMs.

 

[Aeacus]

my motherboard is a maximus viii z170 formula and an i7 6700k

Max amount of RAM that your MoBo supports is 64GB.
specs: https://www.asus.com/Motherboards/ROG-MAXIMUS-VIII-FORMULA/specifications/

And here's your MoBo's RAM QVL list,
link: http://dlcdnet.asus.com/pub/ASUS/mb/LGA1151/MAXIMUS_VIII_FORMULA/M8F_DRAM_QVL_20160411.pdf

Just check the RAM QVL list and buy that specific RAM that is tested by Asus to work on all 4 slots (4 DIMM) at that speed.
Here i trust the RAM QVL list when picking the RAM to buy. If the MoBo maker (in your case, Asus) wasn't able to get some specific RAM to run in all 4 slots then i'm not going to test by myself if i can get it running in all 4 slots or not.

For example, to get 16GB of RAM at speeds of 3000 Mhz, buy the Corsair Vengeance LPX 16GB (4 x 4GB) DDR4-3000 set,
pcpp: http://pcpartpicker.com/product/2GX2FT/corsair-memory-cmk16gx4m4b3000c15
Same set comes with red heatsinks: http://pcpartpicker.com/product/q8dFf7/corsair-memory-cmk16gx4m4b3000c15r
and blue heatsinks as well: http://pcpartpicker.com/product/C27CmG/corsair-memory-cmk16gx4m4b3000c15b

But if you want to max out the MoBo RAM amount (64GB) at speeds of 3000 Mhz then buy this set of Corsair RAM,
pcpp: http://pcpartpicker.com/product/2mkwrH/corsair-memory-cmk64gx4m4b3000c15

For 2x 8GB (16GB total) at 3000 Mhz, you're looking this RAM,
black heatsink: http://pcpartpicker.com/product/MYH48d/corsair-memory-cmk16gx4m2b3000c15
red heatsink: http://pcpartpicker.com/product/2skwrH/corsair-memory-cmk16gx4m2b3000c15r
white heatsink: http://pcpartpicker.com/product/6ntWGX/corsair-vengeance-lpx-16gb-2-x-8gb-ddr4-3000-memory-cmk16gx4m2b3000c15w
blue heatsink: http://pcpartpicker.com/product/Ntp323/corsair-memory-cmk16gx4m2b3000c15b

From upgrade standpoint and as an example, this RAM set of 2x 8GB at 2800 Mhz is good to buy,
pcpp: http://pcpartpicker.com/product/j8FPxr/a-data-memory-ax4u2800w8g17drz
This RAM is supported on all 4 slots and sold as 2 sticks at a time. You can get the 1st set of 2x 8GB now and in the future, when you'll need more RAM, buy 2nd set of 2x 8GB.

 

[Mark_Lawrence]

If you buy them together as a kit then yes they should all work together (although if you watch the video Aeacus posted apparently running a quad channel kit on a dual channel mobo can occasionally have issues). However, for high speed kits, it sometimes not as easy as simply enabling the XMP profile to get them to run at their rated speeds. Running 4 sticks is harder on the memory controller than 2 sticks, so it's possible you might have more issues with 4 sticks than 2. I honestly don't know how likely you are to have issues, but seeing as there's no upside to getting a quad channel kit over a dual channel kit for a dual channel mobo (assuming you can get a dual channel kit with your desired capacity), why risk it?

It would also allow you to add another two sticks down the road if you need more memory, although mixing kits is always a bit of a gamble.

My motherboard has 4 slots with dual channel memory architecture. So if i buy 1 kit of 4 ram sticks, will it cause me problems?

It is better to populate all slots with identical rams than filling 2 slots first then adding 2 more in the future right? As u said the latter would create issues.

My current mb: https://www.asus.com/Motherboards/ROG-MAXIMUS-VIII-FORMULA/specifications/

My choosen memory: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3200mhz-c16-memory-kit-red-led-cmu32gx4m4c3200c16r

 

[TJ Hooker]

Out of curiosity what do you plan to do with your PC? 16 GB is more than enough for the vast majority of people.

 

[Aeacus]

My motherboard has 4 slots with dual channel memory architecture. So if i buy 1 kit of 4 ram sticks, will it cause me problems?

It is better to populate all slots with identical rams than filling 2 slots first then adding 2 more in the future right? As u said the later would create issues.

My current mb: https://www.asus.com/Motherboards/ROG-MAXIMUS-VIII-FORMULA/specifications/

My choosen memory: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3200mhz-c16-memory-kit-red-led-cmu32gx4m4c3200c16r

1. Your selected RAM isn't listed in your MoBo's RAM QVL list though. Here's 50:50 chance that it may or may not work on your MoBo.
2. In RAM QVL list, the following is written: "When running XMP at DDR4 3200 MHz or higher, the system’s stability depends on the CPU’s capabilities."

Channels on your MoBo are same as on my MoBo (checked your MoBo manual).
If i were you, i'd buy the ADATA XPG Z1 2x 8GB set and populate the RAM slots as follows:
Slot #1 - Channel A - ADATA XPG Z1 8GB (set #1)
Slot #2 - Channel A
Slot #3 - Channel B - ADATA XPG Z1 8GB (set #1)
Slot #4 - Channel B

After some time, when 32GB is needed, i'd buy the same exact set of ADATA XPG Z1 2x 8GB RAM and populate the RAM slots as follows:
Slot #1 - Channel A - ADATA XPG Z1 8GB (set #1)
Slot #2 - Channel A - ADATA XPG Z1 8GB (set #1)
Slot #3 - Channel B - ADATA XPG Z1 8GB (set #2)
Slot #4 - Channel B - ADATA XPG Z1 8GB (set #2)

 

[Mark_Lawrence]

Out of curiosity what do you plan to do with your PC? 16 GB is more than enough for the vast majority of people.

I'm a gamer of some heavy graphics games, user of softwares that uses a lot of ram such as autocad, inventor and other 3d softwares and i like to open a lot of tabs in my browser and uses multiple programs at a time.

 

[Mark_Lawrence]

My motherboard has 4 slots with dual channel memory architecture. So if i buy 1 kit of 4 ram sticks, will it cause me problems?

It is better to populate all slots with identical rams than filling 2 slots first then adding 2 more in the future right? As u said the later would create issues.

My current mb: https://www.asus.com/Motherboards/ROG-MAXIMUS-VIII-FORMULA/specifications/

My choosen memory: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3200mhz-c16-memory-kit-red-led-cmu32gx4m4c3200c16r

1. Your selected RAM isn't listed in your MoBo's RAM QVL list though. Here's 50:50 chance that it may or may not work on your MoBo.
2. In RAM QVL list, the following is written: "When running XMP at DDR4 3200 MHz or higher, the system’s stability depends on the CPU’s capabilities."

Channels on your MoBo are same as on my MoBo (checked your MoBo manual).
If i were you, i'd buy the ADATA XPG Z1 2x 8GB set and populate the RAM slots as follows:
Slot #1 - Channel A - ADATA XPG Z1 8GB (set #1)
Slot #2 - Channel A
Slot #3 - Channel B - ADATA XPG Z1 8GB (set #1)
Slot #4 - Channel B

After some time, when 32GB is needed, i'd buy the same exact set of ADATA XPG Z1 2x 8GB RAM and populate the RAM slots as follows:
Slot #1 - Channel A - ADATA XPG Z1 8GB (set #1)
Slot #2 - Channel A - ADATA XPG Z1 8GB (set #1)
Slot #3 - Channel B - ADATA XPG Z1 8GB (set #2)
Slot #4 - Channel B - ADATA XPG Z1 8GB (set #2)

I will be taking the risk. I like my chosen ram because it has nice led bar. But i doubt that it wont run properly on my mb. But when it do, i'll do a little overclock to my cpu to stabilize with my memory. I guess it is what that "When running XMP at DDR4 3200 MHz or higher, the system’s stability depends on the CPU’s capabilities." phrase mean because the memory controller wont be able to catch up with the memory frequency itself thus overclocking will be required. (I've learnt that previously from another forum)

 

[Aeacus]

I will be taking the risk. I like my chosen ram because it has nice led bar. But i doubt that it wont run properly on my mb. But when it do, i'll do a little overclock to my cpu to stabilize with my memory. I guess it is what that "When running XMP at DDR4 3200 MHz or higher, the system’s stability depends on the CPU’s capabilities." phrase mean because the memory controller wont be able to catch up with the memory frequency itself thus overclocking will be required. (I've learnt that previously from another forum)

You're free to go with the RAM you chose. The thing with it's 50:50 chance of working is due to the fact that there are ton of different RAMs available and MoBo makers don't have time nor manpower to test out all the different RAMs.

There are, however, 3000 Mhz Corsair Vengeance LED RAMs too,
specs: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3000mhz-c15-memory-kit-red-led-cmu32gx4m4c3000c15r

But if you want the fastest Corsair Vengeance LED RAMs that your MoBo supports then you can go for 3466 Mhz ones,
specs: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3466mhz-c16-memory-kit-red-led-cmu32gx4m4c3466c16r

 

[TJ Hooker]

The chance of non QVL RAM working is way higher than 50%. It's quite likely to work.
I have used an 8 and then 16 GB kit with my mobo, neither of which were on the QVL, both of which worked fine.

 

[Mark_Lawrence]

I will be taking the risk. I like my chosen ram because it has nice led bar. But i doubt that it wont run properly on my mb. But when it do, i'll do a little overclock to my cpu to stabilize with my memory. I guess it is what that "When running XMP at DDR4 3200 MHz or higher, the system’s stability depends on the CPU’s capabilities." phrase mean because the memory controller wont be able to catch up with the memory frequency itself thus overclocking will be required. (I've learnt that previously from another forum)

You're free to go with the RAM you chose. The thing with it's 50:50 chance of working is due to the fact that there are ton of different RAMs available and MoBo makers don't have time nor manpower to test out all the different RAMs.

There are, however, 3000 Mhz Corsair Vengeance LED RAMs too,
specs: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3000mhz-c15-memory-kit-red-led-cmu32gx4m4c3000c15r

But if you want the fastest Corsair Vengeance LED RAMs that your MoBo supports then you can go for 3466 Mhz ones,
specs: http://www.corsair.com/en/vengeance-led-32gb-4-x-8gb-ddr4-dram-3466mhz-c16-memory-kit-red-led-cmu32gx4m4c3466c16r

First of all thanks for spending time for searching rams that will be compatible to me but all the rams you suggested aren't found on the qvl link you gave to me in your previous reply. Where could i find them?

 

[Mark_Lawrence]

The chance of non QVL RAM working is way higher than 50%. It's quite likely to work.
I have used an 8 and then 16 GB kit with my mobile, neither of which were on the QVL, both of which worked fine.

Maybe the qvl is just for people who need extra reassurance that what they purchase will not go into waste.

 

[Mark_Lawrence]

And here's your MoBo's RAM QVL list,
link: http://dlcdnet.asus.com/pub/ASUS/mb/LGA1151/MAXIMUS_VIII_FORMULA/M8F_DRAM_QVL_20160411.pdf

Not that i dont trust but, can i ask where did you find this qvl link for my motherboard (maximus viii formula)? I cant find it on the asus website or anywhere on the net.