storage Are DRAMless SSDs a good buy now?

[Albert F]

Ok, so we all know a few years back DRAMless SSDs were not recommended in any way shape or form. But now with more and more drives going DRAMless (like the Samsung 980) are they a good deal? 

 

I am looking to buy an M.2 NVME drive to use as my main storage device and being on a budget DRAMless drives are all I can afford.

 

(first time m.2 user here)

[mariushm]

DRAM presence or lack of was way overrated even back then.

Modern SSDs work around the lack of DRAM and substantially reduce the performance gap by using HMB .. by borrowing some memory from the computer - most SSDs reserve up to 64 MB of RAM to use as DRAM was used before HMB was a thing.

 

For a regular home user DRAM doesn't matter. As a Samsung 980 owner, I can tell you for sure it's a perfectly fine drive. I basically flipped a coin between this and a WD SN570 - went with 980 because of the higher slc write cache which allows for longer sustained write speeds.

[ZetZet]

Yes. DRAM is pretty much only useful in synthetic benchmarks these days. In real world usage it's not noticeable. 

 

https://www.techpowerup.com/review/wd-blue-sn570-1-tb/16.html

 

Techpowerup rates based on real world performance and DRAMless SSDs easily make it among the top models. 

[Albert F]

49 minutes ago, mariushm said:

DRAM presence or lack of was way overrated even back then.

Modern SSDs work around the lack of DRAM and substantially reduce the performance gap by using HMB .. by borrowing some memory from the computer - most SSDs reserve up to 64 MB of RAM to use as DRAM was used before HMB was a thing.

 

For a regular home user DRAM doesn't matter. As a Samsung 980 owner, I can tell you for sure it's a perfectly fine drive. I basically flipped a coin between this and a WD SN570 - went with 980 because of the higher slc write cache which allows for longer sustained write speeds.

So you are basically saying that I should look for a SSD that has HMB and I should be good?

[mariushm]

I'm saying you should not care about it all.

Look at the read and write speeds and endurance and that's all. Get something with TLC memory and not QLC (as QLC is super slow once the write cache is filled) and you're good.

 

DRAM was only used to keep track of where files are stored in the memory chips, more precisely where each cluster or sector is in the memory chips (because SSDs don't store data linearly like mechanical drives). Without DRAM, this information is stored in a hidden area of the SSD flash memory.

 

So whenever the operating system requests data from SSD from a particular location, the ssd controller has to check a table to see where the data is actually stored (in which chip, which layer, which chunk of memory). When you write data to the SSD this table also has to be updated.

 

DRAM was used to copy that table from SSD to RAM when SSD boots and keep it in ram so that it's read slightly faster which meant higher read/write IOPS, which only means the SSD has the potential to read a lot more files in parallel or write more files in parallel, at the same time.

 

You as a regular person, just using a SSD, will very rarely be in the situation where you use an application that writes to 50-100 files at the same time, in parallel, or you're reading from 1000 files at the same  time ... most games read a couple of files in parallel at most, and they mostly read huge files in memory, so presence or lack of DRAM makes absolutel no difference to you.