Leading suppliers of enthusiast-grade memory modules, such as Corsair, have already announced their upcoming DDR5 SDRAM sticks that feature rather unprecedented data transfer rates that start at 6400 MT/s and go all the way up to 12600 MT/s. To a large degree, such extreme speeds will be enabled by on-board power management ICs (PMIC) and voltage regulating modules (VRM), which will require proper cooling, Corsair said this week.
"DDR5 conceivably could run much hotter than DDR4 [as] they have moved voltage regulation off the motherboard itself and now it is on the [module], so you actually could be pumping a lot more heat," George Makris, DIY marketing director at Corsair, said in a YouTube video from the company.
For years, many considered heat spreaders unnecessary for most DDR3 and DDR4 modules, even those intended for enthusiast-grade PCs. With DDR5, things may change as modules will get more complex. Corsair says that its upcoming cooling systems for DRAM sticks will do the job.
The DDR5 was developed to support tangible performance scaling for years to come. This data transfer rate scaling is enabled by multiple architectural peculiarities of DDR5 that will allow DRAM makers to produce JEDEC-standardized DDR5-12600 chips in the future. Yet it does not look like any manufacturer is going to fab DDR5-10000 or DDR5-12600 DRAM ICs in 2021 or 2022, so to make appropriate DIMMs manufacturers will have to handpick capable chips, increase their voltage beyond normal 1.1 Volts and ensure quality power delivery.
Since DDR5 modules have their own PMIC and VRM, module producers can develop rather capable solutions to allow overclocking. For example, Adata is already mulling 1.6 Volts for its range-topping DIMMs (we can only wonder how memory controllers of CPUs produced using 5nm or 7nm-class process technologies will handle such signaling voltage, which is a 45% increase from the standard 1.1 Volts. Such an extreme overvoltage will obviously make memory chips hot. Furthermore, PMIC and VRM components will have to be cooled too. Therefore, enthusiast-grade DDR5 modules (at least the best of RAM modules) might need better cooling than their DDR4 counterparts.
Corsair has a lot of experience designing sophisticated cooling systems for its Dominator memory modules that not only cool DRAM chips themselves directly, but can also cool down the module's PCB as well since the latter has special layers. To that end, Corsair is sure that it will offer comprehensive heat spreaders for DDR5 modules too.
So spacing out the DDR5 slots (on the same channel) will help with cooling the RAM when both are populated (2DPC) but will at the same time reduce the speed the memory can run at. With only one slot per channel populated (1DPC) the frequency degradation will be smaller but on the other hand there's very little benefit to cooling in that scenario too.
So I doubt they'll go that route since it would hurt the "sticker" memory frequency that motherboard vendors use for advertisement, the primary number they advertise is 1DPC which would be best with narrow slot spacing, the 2DPC number is listed but I also expect they'll be just fine with pointing a massive and noisy fan on the 2DPC configuration if that's what's necessary to get the best possible frequency for 2DPC.
The only thing QDR does is reduce the amount of power needed for clock distribution. Also, DIMMs have a "strobe" signal (basically a clock) for each 8/9bits word and the other end uses strobe edges to clock data in, can't do that anywhere as easily if those were changed to QDR.
IBM's OMI (Open Memory Interface) that is capable of 1 TB/s transfer speeds seems like the right path for the industry to follow.
Corsair had something like these for some of their overclocked ram, though it was overkill unless you had a tight case and everything else overclocked too, this will now be needed for those.
Not a terrible thing, but if that fan dies… data corruption would be real fast, so if I were going to buy I would get ECC DDR5, unless operating systems/UEFI can implement temperature monitoring and actions.