DRAM on SSDs is typically used to store controller data. A lot of people assume that it's being used as a file-swap space and thus imparts write-though cache like benefits but that is not in fact it's use. That is the job of the cache (typically SLC cache) where files are temporary stored and organized until the controller is ready to actually write the data to NAND cells.
I just didn't respond to it because I don't disagree with it.
Dram can be used for more than one function, but yeah using say 1GB of ram as a write cache is a pretty poor use because that doesn't absorb much data.
Mind you even putting aside that gross mis-statement, it very easy to disprove the idea that being DRAM-less automatically cripple's a drives random write performance.
Never said anything like that. All I said was its a factor, and not irrelevant. Didn't say there weren't other factors, or other ways to achieve the same result.
I also never said dramless drives are not making progress, because it seems they are, you can tell by how many midrange ssds are now dramless. When before only low end was.
Its just I fell for that same line twice before and it ended up not being my real world experience, so I'm just sticking with dram from now on. It may be true, but I'm just not going for it a third time. Whole fool me once thing. Except I was fooled twice.
Random writes are absolutely not "really the important part" for consumer workloads.
Perhaps not for an average consumer? Idk. Its just sequential is getting so high pretty much regardless of what drive you have, that not having good random will really lock things up in long real world writes.
EDIT: Also, dram helps with random reads too. I mean you said it yourself, "it holds controller data" or in other words, its an index of your files, well thats the primary use. When you have faster access to the index, you have faster access to the files. When I said random writes I really should have said random transfers, because you're right, reading is more important for your average user. But dram is still helpful in that regard too.
But to be clear, helpful doesn't mean it is the only way or if you don't have it, you will have terrible performance. Thats not what I'm saying and never did, please don't put words in my mouth.
Anyway, not having good random writes can be detrimental even in short writes, my 40gb of random gamecube games with a few versions of dolphin in there ( I know its a weird test to have but thats my first go to) does have a section with a lot of small files, and the difference between the two drives ( or three technically) really shows the importance of random. Since the one with higher sequential, without help from primocache, takes twice as long. And they both have enough pslc cache to absorb 40gb.
Well we don't actually know how much pslc cache the new mx500 has, but they'd have to nerf it down pretty far for 8tb to not have 40gb of slc cache. Sorry I know this whole sata thing is really not super relevant compared to pcie 5x4 and all the new stuff, but it is my most recent experience since all my m.2 slots are full, which is why I keep bringing it up.
Its just that is what really made me realize the importance of random. When a drive with less sequential can complete a read + write task twice as fast, really goes to show.
Anyway, looking at fill whole drive, here's the MP700 2tb
Here's my nv7000 2tb
(though be wary, I hear this is another vendor that likes to switch parts around - none the less, mine performs amazingly when in a 4x4 slot, and even in the 3x1 slot, my p5 plus did NOT like the 3x1 slot and performed terribly, but performs well in a 4x4, thats why I have the worse drive in the better slot, I know, sounds counter-intuitive but I thought it would be better to have two well performing drives than one amazingly performing drive and one terribly performing one)
And seems TPU doesn't have a review for the sn850x at all that I can find, or for the 2tb p5 plus. The 1TB p5 plus loses slightly because of shorter burst period from less pslc cache but if you look at how far the MP700 falls compared to how far the P5 falls, MP700 falls further. So I would think the 2TB might take the lead. IDK. It would be close either way...... And considering the MP700 is a whole pcie gen ahead....
Anyway I don't want to fight with you, I have my preference and I admit its painted with a bit of bias from my recent experience with dramless drives and I never hid that fact.
