# CPU-Z shows Quad channel



## LUXIL (Feb 27, 2022)

Hi Guys, I would like to know why CPU-Z shows that I have Quad Channel when I have only 2 stick installed as Dual Channel. Is it bad or good :/ ?

Thanks


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## Athlonite (Feb 27, 2022)

DDR5 is dual channels per Dimm whereas DDR4 is only single channel per Dimm so it's fine


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## ThrashZone (Feb 27, 2022)

Hi,
Looks like it's too fast to read lol


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## Wirko (Feb 27, 2022)

CPU-Z knows how much you paid for your DDR5 and is now trying to cheer you up. Don't worry, the piping from your CPU to RAM is still "normal" width, 128 bits in total. Most of the industry, including Intel and motherboard makers, calls it two-channel. The new thing about DDR5 is that each of the two 64-bit channels can operate as two separate 32-bit channels, and those are sometimes called "subchannels".


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## W1zzard (Feb 28, 2022)

Athlonite said:


> DDR5 is dual channels per Dimm whereas DDR4 is only single channel per Dimm so it's fine





Wirko said:


> Most of the industry, including Intel and motherboard makers, calls it two-channel. The new thing about DDR5 is that each of the two 64-bit channels can operate as two separate 32-bit channels, and those are sometimes called "subchannels".


That. It's just a slightly different way how CPU-Z names it


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## mrthanhnguyen (Feb 28, 2022)

It is bad coz you have micron chip.


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## ir_cow (Feb 28, 2022)

DDR5 shows up as quad because of the 2x32 bus to CPU-Z. It should still be dual channel. So Intel says, though Quad makes more sense from a technical standpoint.


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## fadideeb (Oct 11, 2022)

Hello

please CPU-Z shows that my ram channel 4 x 32-bit
I have 16gb 2*8gb of ddr5 4800MHz

one of the ram is micron and the other one is kingston fury

what does that mean ?


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## 3x0 (Oct 11, 2022)

Each stick is 2x32bit, so since you have two sticks it's 4x32bit


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## fadideeb (Oct 11, 2022)

3x0 said:


> Each stick is 2x32bit, so since you have two sticks it's 4x32bit



thank you


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## Benja (Nov 4, 2022)

3x0 said:


> Each stick is 2x32bit, so since you have two sticks it's 4x32bit


so that means dual channel as well?


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## 3x0 (Nov 5, 2022)

4x32bit is dual channel DDR5


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## LabRat 891 (Nov 5, 2022)

Now that the question has been thoroughly answered... 
Does that imply DDR6 will have 2x64-bit/stick?


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## agent_x007 (Nov 5, 2022)

Actually, it's more likely it's going to get 4x 16-bit (if it's necessary), than 2x 64-bit.
As using smaller width allows for more effective use of bus.
In 64-bit vs. 2x 32-bit example :
If you don't have 64-bit's to transfer one way, some part of bigger bus is wasted on each cycle.
While 2x 32-bit get's you a read of 32-bits from memory and at the same time write 32-bit in another part of memory (<== very simplified).
DDR4 dual rank memory does similar thing to ^this, that's why dual rank DDR4 is considered faster at the same clock speeds.


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## Wirko (Nov 5, 2022)

agent_x007 said:


> Actually, it's more likely it's going to get 4x 16-bit (if it's necessary), than 2x 64-bit.
> As using smaller width allows for more effective use of bus.
> In 64-bit vs. 2x 32-bit example :
> If you don't have 64-bit's to transfer one way, some part of bigger bus is wasted on each cycle.


Hm, that's all approximately true but I'd still add a few things.

Actually, one of the few things already known about DDR6 is that it will have four 16-bit channels per module (and will be twice as fast, which surprises no one). 2x 64-bit on one module would be next to impossible. For one, the connector would have to be twice as dense (more or less), or maybe implemented in two levels (like the AGP bus).

Many narrower channels do have a small advantage over fewer wider channels in theory but the memory controller just gets more complex, and it's complex enough as it is. I'm not even sure if client CPUs make use of those 32-bit subchannels. Server CPUs more likely will. Someone would have to create a specialised benchmarking program to prove or disprove that.

Narrower channels also have at least one disadvantage. The smallest unit of data transfer is 64 bytes (512 bits), that's one cache line. If you do that over a 64-bit bus, it will take 8 transfers = 4 clock cycles. If you do that over a 32-bit bus, it will take 16 transfers = 8 clock cycles.



agent_x007 said:


> While 2x 32-bit get's you a read of 32-bits from memory and at the same time write 32-bit in another part of memory (<== very simplified).


DDR5 is also not a dual port memory (if anyone thinks of it as such). One subchannel accesses one half of total memory on the stick, the other one accesses the other half. They are also interleaved, so it's not a simple divison like channel A = first 8 GB, channel B = second 8 GB. It's like channel A = first 64 bytes, channel B = next 64 bytes, and so on. So the benefit of narrower channels is pretty limited, I think.



agent_x007 said:


> DDR4 dual rank memory does similar thing to ^this, that's why dual rank DDR4 is considered faster at the same clock speeds.


Yes. However, a single rank DDR5 module is made of two mostly independent halves so it physically can't have just one rank. It has two. But if a CPU can't use two subchannels separately, it also can't take advantage of doubled ranks. By extrapolation, a dual rank module probably has four ranks?


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## aQi (Nov 10, 2022)

The fact that ddr5 has sub channels. Well nothing wrong anywhere in your scenario just enjoy more bandwidth.


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