DDR3 PC3- instead of PC3-?

Question

RAM

A piece of iron question: if the type of supported memory is written in the specification for the motherboard, for example, PC3-10600 (1066) - is it possible to put PC3-12800 (1333) instead of it?
A more general question: do memory strips designed for a higher frequency work at a lower one? As an extreme example: DDR3-2133 instead of DDR3-800. Or are there other characteristics besides frequency that make it backwards incompatible? And then at the same price, I would buy a more "older" version.
One of the questions in the series: "Everything you wanted to know about memory, but didn't bother to ask."

Answer 1

Will work without problems. The manufacturer indicates the guaranteed speed (frequency) of the bar. Plus, manufacturers often “sew” several modes of operation - there will be different timings at different frequencies. Higher speed means more latency. And vice versa.
But in any case, the memory bar will work at a lower speed.
When compared with cars, they write maximum speed - 180 km / h. 200km/h This does not mean that you can’t do less ... you can go 5 km / h. Also, some models can be overclocked a little faster than the calculated ones. Same thing with the operating system. There are only a few nuances - it is necessary to increase the timings during overclocking. But this is already beyond the scope of the question raised.

Answer 2

То есть наоборот, при меньшей частоте будет меньшая задержка?
Right.
Higher speed - higher timings (more delay).
Lower speed - lower timings = lower latency.
But the relationship is not linear.

Answer 3

Right.
Higher speed - higher timings (more delay).
Lower speed - lower timings = lower latency.

Not true :)
Timings are measured in cycles.
The “duration” of a cycle is 1/frequency.
So memory with high frequency and high timings may have less timing delay than memory with low frequency but small timings.

Answer 4

In theory, everything should work, but in practice, sometimes there are cases of incompatibility. Therefore, before buying memory, it is advisable to familiarize yourself with the list of compatible memory with your board (usually there is one on the motherboard manufacturer's website). There is nothing more to add, everything has already been said, although for greater educational program, keep the article - “First look at DDR3. Exploring the next generation of DDR SDRAM, theoretically and practically
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Answer 5

The general answer is yes. But there are exceptions, and I have encountered them. Sometimes it helps to set the timings and frequencies manually in the BIOS, then the higher frequency dice that have not worked start to be seen in the system, and most often there are no problems.