If you want to know quickly why they do not create faster RAM memories for our PC, first of all we must clarify that by this we mean the speed at which data is transmitted. Which involves increasing the clock speed at which they operate and at the same time the voltage. This increases power consumption and because there is no material in the known universe with 100% efficiency, and which can transmit electrical signals without distorting them, then what we have is that heat is released. Thus, the main problem with RAM is its temperature and, consequently, excess heat.
Why aren’t faster RAMs made?
There are many types of RAM on the market, both for the processor and for the graphics card. Although in general we have two types of memory cells. The first is SRAM memory which is used in processors and therefore in registers and cache memories. The second is the DRACHMAwhich is used in different types of memory external to the processor such as DDR, LPDDR, HBM, GDDR, etc.. They all store every bit of memory in the same structure, consisting of a transistor and a capacitor.
The problem is that the higher we raise the temperature, the more likely it is that the structure lose the electrical charge stored there and with it the information. So you get to the point where it can’t be held and its main function is lost. Since the processor needs this memory to function and run programs, overheating of this memory becomes a problem.
The RAM temperature limit for this is 85°C as a general rule, and even some modules are meant to run at lower speeds. Since DRAM requires constant refreshes, if the RAM temperature increases, refreshes must be more frequent. The paradox? Such an operation even more heat in the RAM. So in the end the result is the same. Curiously, 5% of the circuits in RAM are not used to store or transmit data, but to prevent data loss.
SRAM as RAM instead of DRAM?
SRAM, on the other hand, does not have this problem, no need to refresh, but because it needs more transistors per bit, it cannot give as much storage capacity. That’s why we don’t see SRAM as system RAM and we don’t see high-speed DRAM as cache. In the second case, it would not be able to run at CPU speed and would be a performance bottleneck. Also, the reason AMD chose V-Cache to be SRAM and not DRAM is precisely because the temperature problem.
So, if it is true that we could see SRAM memory chips, we would find that, for example, 2 GB of SRAM memory would cost us about 8 GB of DRAM memory. Taking into account the lack of optimization of applications in terms of the amount of memory used. On the other hand, the communication interfaces would not consume less, but even more and, consequently, this would significantly increase the energy consumption.
The RAM temperature problem will get worse in the future
The other point is that the solution for the industry as a whole has been to press the accelerator and increase the average consumption of each of the computers. In the midst of a world where all the action of the various world leaders is to reduce the carbon footprint, well the logic is that sooner or later the various manufacturers are going to hit a wall of regulations and restrictions in this point. Something they take into account in the long term, but not in the short and not in the medium term.
For the moment, the RAM memory has not “benefited” from the corresponding increases in consumption. However, we have already seen the occasional model, which is still a curiosity, with active cooling and, therefore, using fans. Let’s also not forget that once the CXL standard is normalized, it is possible that we will see memory modules not in the form of DIMMs, but in PCI Express interfaces and therefore in the form of cards with their cooling. Sincerely and from here we hope that this will never happen.
Although, and finally, it will be a huge challenge in future memories with greater capacity. To the extent that the distance between the transistors decreases by reducing them the more the problems of thermal drowning increase. Thus, the temperature in the RAM is not only an issue when it comes to speed, but also when it comes to storing data. Thus, for some time now, the capacity jumps are not like they were a few years ago.
