IsenstaedtAs far as I know, the ATi Radeon HD 3870 was the only graphics card to use (G)DDR4.

blibbaI don't think you understood the point of my post. I don't really understand the point of yours - yes hardly anyone who knows what they're doing uses single channel, but a) what has this got to do with overclocking, and b) what has this got to do with my post? Also, I hate to be the anal one, but you really ought to clean up posts like that before you hit "post". The grammar and punctuation is bad to the point that it's very difficult to understand for those of us that didn't write it.

SIGSEGVsorry, english is not my primary language. but my point is with abundant and cheap ddr3 memory in retail market, is there anyone here still using single mode rather than dual mode? what's the point using single channel? what will you do with ddr4 on single channel? i think dual channel mode is enough to do multitasking computation, except you're working with super heavy computation such as 3d objects rendering etc. that's why ddr4 is used for enterprise server systems

blibbaAlso, you seem to imply that single-channel means a single stick of RAM. This is not the case. If you use a Celeron G530 with two identical sticks of RAM, for example, it'll be single channel.

IntelMemory Specifications
Max Memory Size (dependent on memory type) 32 GB
Memory Types DDR3-1066
# of Memory Channels 2
Max Memory Bandwidth 17 GB/s

AquinusWell, you can stop thinking about channels because DDR4 doesn't work that way. DDR4 uses point-to-point links a lot like how PCI-E works. So each DIMM has its own set of memory links so each chip by itself is capable of independent memory operations. That is what I gathered from reading the spec, so memory controllers will have to change a good amount to accommodate it.

AquinusThe G530 has two memory channels, so your example is incorrect. Not to say that isn't how it works, but even modern systems with two channels will run dual-channel even if the memory sizes are different so you'll find it really hard to run single channel if the motherboard gives you the option. I bet you it won't though because channels typically aren't switched, they're hard wired.
ark.intel.com/products/53414/Intel-Celeron-Processor-G530-(2M-Cache-2_40-GHz)

AquinusWell, you can stop thinking about channels because DDR4 doesn't work that way.

DDR4 uses point-to-point links a lot like how PCI-E works.

So each DIMM has its own set of memory links

so each chip by itself is capable of independent memory operations.

largonEvery DDR-SDRAM chip so far can do that.

blibbaThe only relevance of DDR4 to the consumer market is the potential development of GDDR6.

Current high-end consumer systems don't even benefit from the bandwidth of DDR3. Set your Z77, Z68, X58 or X79 rig to single channel. The performance will barely be altered by a colossal bandwidth reduction. Severs do benefit though, or so I'm told.

AquinusNot at the same time. As you said, channels are interleaved. ;)

largonNot sure what you mean. If you got and n-channeled memory controller and as manu single rank DDR3 DIMMs onboard, the mem ctrl can R/W all the chips at the same time. If there's more than n ranks though, then it's a nono as the interface is just n64bit*. I removed the line about DDR4 lacking rank interleaving from my earlier post 'cause it makes no sense and I don't know why I wrote it. DDR4 can do rank interleaving just fine.

*three and 3×64bit for tri channel Nehalem.

AquinusDDR4 in server configurations will be switched a lot like how PLX did with their PCI-E bridge chip.