If we have ssd’s that exceed the 2tb mark, why are RAM modules still limited in size?

Question

I understand that even the fastest nvme drive is way slower than RAM, but surely that isn’t the only reason we don’t see 1tb memory modules on the market. I was only able to find 512gb modules in my searching, and that was for servers.

In: Technology

Answer 1

Hi,

I am quite frankly aghast at the trolls to this question. Because it is a REALLY good one, to which I do not know all the answers.

So I’ll say a few things first. Many people do not know the difference between RAM and storage. Many people don’t know the difference between SSD and HDD. Many people don’t know the difference between volatile and non-volatile. Most people don’t understand the complexities of creating none volatile solid state storage.

And that’s the crux of it. RAM and STORAGE are two VERY different requirements and have two very different technologies. The former is to allow the CPU (And it’s cache / DMA friends) to access the RAM, where the program code is and run it as fast as possible. The latter is for long term (that is to say {out of memory} storage) for later retrieval by the CPU.

The reason that Memory is faster is because it doesn’t have to latch, that is, to remember it’s previous states.

The reason SSD is all slower per GB is because they HAS to be able to remember.

The chips used for SSD/ M2 /PCI are fairly flatlined now – only the interface and ways of combining those chips into something reliable (Variations of RAID, and ECC, if you will) is happening..

So RAM is faster because it has far fewer responsibilities (when working!) than storage, it is closer to the CPU (in literal mechanical terms and logical access terms) and it is made from smaller components, which are more simple than storage components (No need for memory (AKA storage)) and can therefore run at a much higher clock rate and have greater throughput.

NOW THEN. With greater density comes greater heat responsibility and greater potential for loss. You can’t just stack RAM like you can storage (Both were tried / both failed) Because RAM can run close to the speed of the signals feeding the CPU it needs to be an expensive bit of wafer.

I’m gonna leave you to google ‘Wafer’, ‘CPU Wafer’ or ‘news about electronic wafers’

Hope this helps dude. Don’t let the other bastards put you off. Can’t have too much RAM or correctly tiered storage.