What is JEDEC? Plus other questions

[opio]

Apparently the highest JEDEC speed for DDR3 is 2133mhz

What does this mean?

 

[Calculagator]

That means DDR3 cannot run faster than 2133 MHz without overclocking it. Memory that lists a faster speed is built to be overclocked to reach that speed. Unless a motherboard overclocks automatically, you would need to manually set the speed to be the faster speed.

 

[WyomingKnott]

Are you referring to the JEDEC speed profiles stored on ram sticks, that tell the BIOS what speeds the ram runs at by default? Or you do mean that JEDEC ( Joint Electron Device Engineering Council, a standards organization) has decreed that DDR3 shall never be run above 2133 mhz?

 

[Tradesman1]

That JEDEC is way behind the times 😉 JEDEC is the Joint Electron Device Engineering Council and supposedly they lay out the standards for DRAM....Problem is they are years behind. Based on their 'Standards DDR3 originally was only to go up to 1600, and by they time they finally issued standards for 1866 and 2133, those sticks had already been out for a couple of years. The DRAM manufacturers took it upon themselves to sort of make their own stands as they went (with GSkill and to a degree Corsair sort of leading the way). DDR4 was to be the onward progression of DDR3, which is why it hhas and runs such high CLs and timings. I anticipate the manufacturers tightening the timings up and getting closer to DDR3 CLs once additional lines of CPUs and mobos arrive that support DDR4

 

[opio]

Thank you!

 

[Tradesman1]

No worries

 

[Pinhedd]

That JEDEC is way behind the times 😉 JEDEC is the Joint Electron Device Engineering Council and supposedly they lay out the standards for DRAM....Problem is they are years behind. Based on their 'Standards DDR3 originally was only to go up to 1600, and by they time they finally issued standards for 1866 and 2133, those sticks had already been out for a couple of years. The DRAM manufacturers took it upon themselves to sort of make their own stands as they went (with GSkill and to a degree Corsair sort of leading the way). DDR4 was to be the onward progression of DDR3, which is why it hhas and runs such high CLs and timings. I anticipate the manufacturers tightening the timings up and getting closer to DDR3 CLs once additional lines of CPUs and mobos arrive that support DDR4

It's not that JEDEC is behind, it's that the DIMM manufacturers are getting ahead of the SDRAM manufacturers.

SDRAM manufacturers = Samsung, Hynix, Micron

DIMM manufacturers = G.Skill, Corsair, Kingston, etc...

The DIMM manufacturers aren't creating standards at all, they're simply interpolating and extrapolating upon the JEDEC standards that the SDRAM manufacturers adhere to.

 

[Tradesman1]

JEDEC started writing DDR4 specs back in 2004 or so, which was the progression from the DDR3 specs they were writing. CLs continued up from the base DDR3 specs, i.e. believe they planned 2133 to be CL12, 1866 to be CL11 etc, and note 1866 basically got dumped from the DDR4 lineup as it was outdated. Rather than rewrite to what DRAM manufacturers have taken things to, they have stuck to their already ancient expectations. We've had DDR3 2133 at CL9 for a few years now, yet the DDR4 is 'to spec' at 12 and higher. Additionally I have to beg to differ, it's the manufacturers who have been basically setting standards for DDR3 going back to 1866. The companies (like GSkill) are designing and implementing higher data rate DRAM based on what they learn, the leaders are for all intents and purposes setting the standards for the lower end DRAM manufactures to follow as far as timings. Their R&D departments are already looking into tightening timings that vary from JEDEC spec for the performance people want. They 'planned' to have specs up through 3200, and yet there is already DDR4 3300, which barely is higher than available DDR3 rates