Quad-channel vs dual channel whats the difference ?
- Thread starter 2013
- Start date
No nothing to do with the extra physical DIMM slots slots per say. Rather with Quad channel you increase memory bandwidth. With 4 stick's you quadruples with memory bandwidth vs what you get with a single stick. As the name may indicated Dual Channel doubles the Memory Bandwidth.
The real world benefit of this varies depending on the task and application your working on.
The real world benefit of this varies depending on the task and application your working on.
Thanks I did not know, I was just wondering because intel use quad but AMD chose to use dual even on the next AM4 platform.
It is to do with the number of slots but only in so far as you need the necessary number of slots to do it. The reverse isn't true - just because you have four RAM slots doesn't mean you have quad-channel memory. Single, dual and quad-channel are to do with how your system accesses the memory.
A simple and reasonable analogy would be lanes on a motorway. Just because you have them doesn't mean that the cars on them are going any faster or slower. It means you can carry more passengers at once. Now that may sound like a good thing and if there's no extra cost to having it then of course you want it. But there is a cost and you don't necessarily need it - you have to look at what you're doing. In our motorway analogy there's a destination those cars are going to. Now maybe that destination can handle that many people, but very often it can't. For example in gaming, I'd be surprised if there was any difference that a human could detect. In rendering a 3D model with a lot of detail in Maya or something, maybe there is. But usually what matters is the speed of the cars and how quickly people can get in them when they know they need to go somewhere. These are memory speed and latency respectively. And I'd say they always matter more. When photoshop wants part of an image for the CPU to work on it sends out the request to the RAM and says "Gimme!". How quickly the RAM responds is latency. How fast it sends over the data is speed. Maybe the CPU can eat enough people, I mean data, at once that it would benefit from quad over dual, but usually it can't.
I would have a look around for benchmarks for your particular use case and see if anyone has done a comparison, but I would say with a fairly high degree of confidence that you wont find enough difference to warrant any cost in higher platform requirements, higher memory cost or anything else. If you already have what you need anyway, sure quad is better than dual. But even a small increase in cost will almost certainly be better spent on the next speed of RAM up or something with better latency.
I hope that helps.
A simple and reasonable analogy would be lanes on a motorway. Just because you have them doesn't mean that the cars on them are going any faster or slower. It means you can carry more passengers at once. Now that may sound like a good thing and if there's no extra cost to having it then of course you want it. But there is a cost and you don't necessarily need it - you have to look at what you're doing. In our motorway analogy there's a destination those cars are going to. Now maybe that destination can handle that many people, but very often it can't. For example in gaming, I'd be surprised if there was any difference that a human could detect. In rendering a 3D model with a lot of detail in Maya or something, maybe there is. But usually what matters is the speed of the cars and how quickly people can get in them when they know they need to go somewhere. These are memory speed and latency respectively. And I'd say they always matter more. When photoshop wants part of an image for the CPU to work on it sends out the request to the RAM and says "Gimme!". How quickly the RAM responds is latency. How fast it sends over the data is speed. Maybe the CPU can eat enough people, I mean data, at once that it would benefit from quad over dual, but usually it can't.
I would have a look around for benchmarks for your particular use case and see if anyone has done a comparison, but I would say with a fairly high degree of confidence that you wont find enough difference to warrant any cost in higher platform requirements, higher memory cost or anything else. If you already have what you need anyway, sure quad is better than dual. But even a small increase in cost will almost certainly be better spent on the next speed of RAM up or something with better latency.
I hope that helps.
TBH the main advantage really is areas people don't tend to benchmark - i.e. if you are running a lot of virtual machines especially utilising extended CPU virtualisation features then potentially quad channel bandwidth can be an advantage.
90% of the time or so I see no significant performance difference between my 4820K (Quad Channel 59.7 GB/s) and a 4770K (Dual Channel 25.6 GB/s) for gaming type stuff - infact the 4770K clock for clock can sometimes be a hair faster in some games - there are very specific games that gain slightly from the quad channel memory but they are few and far between (this evens up a bit or even slightly goes to the 4820K if you have a higher end multi GPU setup).
90% of the time or so I see no significant performance difference between my 4820K (Quad Channel 59.7 GB/s) and a 4770K (Dual Channel 25.6 GB/s) for gaming type stuff - infact the 4770K clock for clock can sometimes be a hair faster in some games - there are very specific games that gain slightly from the quad channel memory but they are few and far between (this evens up a bit or even slightly goes to the 4820K if you have a higher end multi GPU setup).
Don't forget that quad channel memory controllers' generally have to run memory at slower speeds than dual channel controllers are capable of due to their increased complexity. So faster memory modules on a dual channel controller can close the gap somewhat with a quad channel controller running its modules at slower speeds