Is my dream triple channel ITX motherboard possible?

[Helpful Tech Witch]

Just now, thDel said:

Yeah it’s a concept for a dream motherboard that doesn’t yet exist.

itx am4 triple channel memory

my question is is it possible

No. No am4 cpu has a memory controler with more then 2 possible sticks, as @jaslion and @Theory_Lukas said. Ans r5000 is the final am4 generation.

 

[thDel]

1 minute ago, mariushm said:

 

Processors that support QUAD channel  also do this interleaving thing but with 4 memory channels, and therefore 4 memory sticks. So it's even better. 

 

it seems like you're stuck with this triple channel speed, when it fact it's nothing special.  Processors (because the memory controller is inside the processor) also do it with dual channel. 

 

There's also the fancy Threadripper Pro processors which have EIGHT channels, each with one memory stick : https://www.pcworld.com/article/3566078/amd-threadripper-pro-has-64-cores-128-pcie-lanes-and-8-channel-memory-support.html

 

Even more - and that screenshot doesn't tell you - is that there's also the concept of DUAL RANK memory sticks, which do something similar. The memory controller can issue some commands to ONE HALF of the memory stick and while that half prepares data (reads it from memory chips and makes it ready to be pushed through the wires to the CPU), the processor actually transfers data from the other half of the memory stick. 

 

 

In REAL WORLD, the benefits of that interleaving and reduction of latency is super small, basically you wouldn't notice it. 

 

In ITX boards, you're limited to 2 memory sticks because PHYSICALLY there's no room on the motherboard for more.  It may LOOK like there's not, but wherever it looks like there's space for some, imagine there's lots of wires going all over the place through the circuit board, in multiple layers. 

In order to put memory slots, there has to be unused areas for the metal pins inside the ram slots to go through and those will block the path of various wires inside the motherboard. 

Some motherboards solve this problem by using laptop style SO-DIMM sticks instead of the long memory slots, but those bring their own complexity, it's not a solution.

 

Ok but in a theoretical world where I had three dims and quad channel cpu. Would I get triple channel speed?

[thDel]

3 minutes ago, HelpfulTechWizard said:

No. No am4 cpu has a memory controler with more then 2 possible sticks, as @jaslion and @Theory_Lukas said. Ans r5000 is the final am4 generation.

 

I don’t understand, does am4 support quad channel? If not what CPUs do?

[tech.guru]

4 minutes ago, mariushm said:

 

Processors that support QUAD channel  also do this interleaving thing but with 4 memory channels, and therefore 4 memory sticks. So it's even better. 

 

it seems like you're stuck with this triple channel speed, when it fact it's nothing special.  Processors (because the memory controller is inside the processor) also do it with dual channel. 

 

There's also the fancy Threadripper Pro processors which have EIGHT channels, each with one memory stick : https://www.pcworld.com/article/3566078/amd-threadripper-pro-has-64-cores-128-pcie-lanes-and-8-channel-memory-support.html

 

Even more - and that screenshot doesn't tell you - is that there's also the concept of DUAL RANK memory sticks, which do something similar. The memory controller can issue some commands to ONE HALF of the memory stick and while that half prepares data (reads it from memory chips and makes it ready to be pushed through the wires to the CPU), the processor actually transfers data from the other half of the memory stick. 

 

 

In REAL WORLD, the benefits of that interleaving and reduction of latency is super small, basically you wouldn't notice it. 

 

In ITX boards, you're limited to 2 memory sticks because PHYSICALLY there's no room on the motherboard for more.  It may LOOK like there's not, but wherever it looks like there's space for some, imagine there's lots of wires going all over the place through the circuit board, in multiple layers. 

In order to put memory slots, there has to be unused areas for the metal pins inside the ram slots to go through and those will block the path of various wires inside the motherboard. 

Some motherboards solve this problem by using laptop style SO-DIMM sticks instead of the long memory slots, but those bring their own complexity, it's not a solution.

 

thats not true there is ITX boards out there with 4 DIMMS but certainly none with 6 for triple channel.

see, https://www.newegg.com/asrock-c3758d4i-4l-intel-atom-c3758-series-processor-8-core-25w/p/N82E16813140012

for example

[Kilrah]

1 minute ago, thDel said:

Ok but in a theoretical world where I had three dims and quad channel cpu. Would I get triple channel speed?

Once again it depends on that CPU and whether it supports it. Apparently it's not the case for TRX40 CPUs.

[thDel]

Just now, Kilrah said:

Once again it depends on that CPU and whether it supports it. Apparently it's not the case for TRX40 CPUs.

Is there any current cpu that does?

[Kilrah]

1 minute ago, tech.guru said:

thats not true there is ITX boards out there with 4 DIMMS but certainly none with 6 for triple channel.

see, https://www.newegg.com/asrock-c3758d4i-4l-intel-atom-c3758-series-processor-8-core-25w/p/N82E16813140012

for example

Well sure but it's a tiny atom, much smaller than a normal full size socket and then the VRMs also don't need to supply 200+W like on a desktop CPU.

[Kilrah]

1 minute ago, thDel said:

Is there any current cpu that does?

Probably not since there's no point in it. You might want to look it up yourself on intel HEDT.

[tech.guru]

Just now, thDel said:

Is there any current cpu that does?

HEDT from intel and xeon

[mariushm]

4 minutes ago, thDel said:

Ok but in a theoretical world where I had three dims and quad channel cpu. Would I get triple channel speed?

Yes, but in a theoretical world you would install 4 sticks and you'd get quadruple channel speed (even better). 

In practice, the performance bumps above dual channel will be very small for most applications, because the data amounts read and written into the ram are SMALL. 

It takes  A LOT of time for the transfer to start (processor sends command, waits for the memory stick to be ready to accept the data, or waits for the memory stick to make the data available to be sent towards the cpu) and then the transfer is done super fast. 

In a large majority of situations the data amounts are so small, that the speed increase by using triple or quad channel is barely noticeable. 

 

Think of it like waiting 10 seconds for the transfer to start, and then taking 1 second to transfer data. With quad channel transfer takes 1s, with triple channel it takes 1.5s, with dual channel it takes 2s 

So in the end it's 10+1  vs 10+1.5 vs 10+2  .... very small performance difference. 

 

In order to see actual performance, the amount transferred to/from ram would have to be BIG enough to actually take more time than the ram latency and delay to commands, and most applications and games just don't deal with such data.

 

[tech.guru]

epyc supports eight channel if you want to go crazy

[thDel]

1 minute ago, tech.guru said:

HEDT from intel and xeon

What is that? 
 

soi understand that my dream of triple channel am4 gloriousness will never be, if there were to be three slots for capacity, would they be in single or dual channel?

[mariushm]

Just now, thDel said:

I don’t understand, does am4 support quad channel? If not what CPUs do?

AM4 supports processors with a controller that has TWO memory channels,  each memory channel allowing for TWO sticks.  The first and third slot are connected to the first channel, the 2nd and 4th slot are connected to the second memory channel. 

 

Motherboards with only 2 memory slots will simply connect only one memory slot to each channel available. 

 

Threadripper supports 4 channels, and up to motherboard manufacturer if it connects 1 or 2 memory slots to each channel. 

Threadripper Pro (like I linked)  has 8 channels and I think only one memory slot per channel is usually found on motherboards (not enough space for 2, and it's way more difficult to have 16 slots)

 

[thDel]

1 minute ago, tech.guru said:

epyc supports eight channel if you want to go crazy

Anyone digging a 7 channel MOBO

[Kilrah]

3 minutes ago, thDel said:

soi understand that my dream of triple channel am4 gloriousness will never be, if there were to be three slots for capacity, would they be in single or dual channel?

Nobody would make that with any existing platform so the question is moot...

[tech.guru]

1 minute ago, thDel said:

What is that? 
 

soi understand that my dream of triple channel am4 gloriousness will never be, if there were to be three slots for capacity, would they be in single or dual channel?

if you want the best its epyc it supports 8 channel memory.

buy a big tower and put a server board and epyc processor.

 

but i personally think you wont benifit from it because you really havnt thought about your use case and why you want the things you are asking for...

[thDel]

Just now, mariushm said:

AM4 supports processors with a controller that has TWO memory channels,  each memory channel allowing for TWO sticks.  The first and third slot are connected to the first channel, the 2nd and 4th slot are connected to the second memory channel. 

 

Motherboards with only 2 memory slots will simply connect only one memory slot to each channel available. 

 

Threadripper supports 4 channels, and up to motherboard manufacturer if it connects 1 or 2 memory slots to each channel. 

Threadripper Pro (like I linked)  has 8 channels and I think only one memory slot per channel is usually found on motherboards (not enough space for 2, and it's way more difficult to have 16 slots)

 

So I would have to fit a threadripper on an itx MOBO for my dream to work? 

thats just physically impossible.

 

if I still did it, would it be that two dimms are connected to one channel and one dimm to the other? Would this be dual or single channel speed?

[thDel]

1 minute ago, tech.guru said:

if you want the best its epyc it supports 8 channel memory.

buy a big tower and put a server board and epyc processor.

 

but i personally think you wont benifit from it because you really havnt thought about your use case and why you want the things you are asking for...

No it’s a dream perfect system. Just trying to learn and to see what is possible.

[Kilrah]

1 minute ago, thDel said:

if I still did it, would it be that two dimms are connected to one channel and one dimm to the other? Would this be dual or single channel speed?

You would decide based on whether you're able to route a 2nd channel on such a cramped motherboard...

[thDel]

1 minute ago, Kilrah said:

You would decide based on whether you're able to route a 2nd channel on such a cramped motherboard...

Ok so my dream is still somewhat alive with a few asterisks.

[mariushm]

Just now, thDel said:

So I would have to fit a threadripper on an itx MOBO for my dream to work? 

thats just physically impossible.

 

if I still did it, would it be that two dimms are connected to one channel and one dimm to the other? Would this be dual or single channel speed?

A sane motherboard manufacturer that puts 3 memory slots and a threadripper socket on ITX motherboard, would wire each memory slot to a memory channel, so you'll get tripple channel if you install 3 memory sticks. 

 

A stupid motherboard manufacturer could wire 2 memory slots to a channel and the third memory slot to the second channel -  the amount of ram common on both sticks will run in dual channel mode (faster), the rest in single channel mode   ex   2 x 8 GB in one channel,  1 x 4 GB  -  you have 1x 4  + 1 x 4 =  8 GB in dual channel mode,  rest of 4 GB from first 8 GB stick + 2nd 8 GB stick  in single channel mode. 

 

It's also a compromise between cost and difficulty of manufacturing  - a 4 layer motherboard (mATX and ATX budget boards) can cost let's say 10-15$ to make. A 6 layer board may cost 40$ to make.  A server 8-12 layer board could cost 60-100$ just in the circuit board, to manufacture.  

 

ITX boards often have 6 layers .... could always add more layers to route the wires but nobody would pay the price to make it.

 

[thDel]

4 minutes ago, mariushm said:

A sane motherboard manufacturer that puts 3 memory slots and a threadripper socket on ITX motherboard, would wire each memory slot to a memory channel, so you'll get tripple channel if you install 3 memory sticks. 

 

A stupid motherboard manufacturer could wire 2 memory slots to a channel and the third memory slot to the second channel -  the amount of ram common on both sticks will run in dual channel mode (faster), the rest in single channel mode   ex   2 x 8 GB in one channel,  1 x 4 GB  -  you have 1x 4  + 1 x 4 =  8 GB in dual channel mode,  rest of 4 GB from first 8 GB stick + 2nd 8 GB stick  in single channel mode. 

 

It's also a compromise between cost and difficulty of manufacturing  - a 4 layer motherboard (mATX and ATX budget boards) can cost let's say 10-15$ to make. A 6 layer board may cost 40$ to make.  A server 8-12 layer board could cost 60-100$ just in the circuit board, to manufacture.  

 

ITX boards often have 6 layers .... could always add more layers to route the wires but nobody would pay the price to make it.

 

If a triple channel rog x670 strix came out next year people would pay big money.

[mariushm]

Just now, thDel said:

If a triple channel rog x670 strix came out next year people would pay big money.

Why? 

Explain why it's SO important to have triple channel. What do you do now that you think triple channel makes SO much better than dual channel? 

Is it just for looks, to have 3 memory sticks, or did you read somewhere that triple channel is the shit or you have some misconception? 

 

[jaslion]

38 minutes ago, thDel said:

Yeah it’s a concept for a dream motherboard that doesn’t yet exist.

itx am4 triple channel memory

my question is is it possible

No no it is not possible. It's dual or quad for trx4 the end. There are quad dimm slot itx boards around no issue. So get over your triple channel dream

[jaslion]

13 minutes ago, thDel said:

If a triple channel rog x670 strix came out next year people would pay big money.

They would never make that as triple channel is an outdated concept. Tech has advanced and the manufacturers all know that they can fit 4 slots on a itx board hell asrock made one for epyc of all things.

 

Triple channel won't happen again the end. No cpu supports it, it's an old concept, it's extra money to implement and they have far better things to do.