Have RAM frequencies been misimterpreted?

[Britton30]

We run CPUz and it tells us that the RAM frequency (speed) is, say, 1066MHz. We are in dual channel mode so we proudly say this RAM is 2133MHz which is how all manufacturers advertise it.

Have we been wrong in this assumption? It would seem so. The frequency in the above example is in fact 1066MHz in single or dual channel mode. The 2133MHz figure is actually MT/s, mega transfers per second, not the true frequency.

I have got this info from this Wiki article: http://en.wikipedia.org/wiki/DDR3_SDRAM

Have we all been wrong for years about dual channel doubling the RAM frequencies?

[damric]

You are right. A kit of DDR3-1600 means 1600 Mega Transfers per Second, not 1600 Million Cycles per Second. Actual DDR3-1600 frequency is 800MHz.

Manufacturers often advertise RAM speed as a misnomer.

This is probably because the general public doesn't know what DDR stands for anyway so it's probably easier for them.

[Tradesman]

This stuff all gives me a big headache. I myself with stick w/ freq, it's quicker to say and type and while say 1066 may refer to clock cycles, since it DDR (Double Data Rate) then effective single data rate is 1066 and DDR is 2133 (granted MT's) which is the rating for a single stick.....Then we look at that single stick which is operating at 64bits, yet when we pair another stick with it in Dual channel then theoretically the bandwidth would double since we are now running at 128bits (likewise for triple channel running at 192 bit and then into true Quad channel (ie a socket 2011 and appropriate CPU and opposed to a common misconception that ANY TIME you are running 4 sticks you are in quad channel, it requires an appropriate mobo/chipset and a CPU w/ a true quad channel MC (Memory Controller)) that runs the DRAM at 256bits), but it doesn't truly double/triple or quad size things.

And lets not forget, DDR4 is just around the corner which will have even higher TRUE clock cycle freqs, believe as an example at 2133 it will produce 4266 MT/s and at lower voltage ranging 1.05-1.2 and soon moving to 1 volt (if all goes as planned/expected) and if DRAM continues as it is, look to see the true clock freq keep going up, and like w/DDR3, JEDEC will be scrambling to set/publish new specs just as they are now (and have been) with DDR3, which I believe currently may cover through 2133 (and we have 2400, 2600, 2666 & 2800 with 3000 and 3200 hitting the market as we speak (well type/read )

[Britton30]

LOL, headaches for me too! and my UEFI also has settings for 2133[B]MHz[/[B] to further add to this misconception. Mentioning the bit rate of RAM helps me to separate DDR and Dual channel in my little pea-brain though. Then there is BSCLK, CPU multi, RAM dividers, HT Link, NB Freq......

Won't DDR4 require a new batch of CPUs too?

[Tradesman]

They've got em in the labs, but have a feeling it'll be like the socket 775, where initially DDR4 will show up in something like the sockets 1155/2011 mobos, much the same as as DDR3 went into use in the 775s (and others) where folks could go either DDR2 or DDR3 (often an equal split or 4 sticks DDR2/2 Sticks DDR3)