PrimoCache: Pros and Cons?

JMSOG · June 28, 2020

TL:DR; is there a good reason NOT to use primocache?

Fuller explanation:

My system has three drives in it: a 500gb NVMe boot drive, a random 2tb hard drive from 2013, and a WD Black 4tb drive from 2015. I'm not doing anything complex with these drives...they were plugged into the computer, formatted, and that was it, no RAID or anything.

To shorten a long story, it turns out I had a 500gb NVMe drive just sitting around, which was (close to) never used. I don't think throwing another 500gb of SSD storage into my system will be especially helpful without adding a lot of management, so I thought it might be interesting to use it as cache instead.

I know Linus seemed to sing the praises of PrimoCache about 1-2 years ago in a video about using Optane on an AMD system. Frankly, it looks pretty good to me:

1: it's non-destructive, so if my cache randomly dies, I won't lose anything (unlike StoreMi)

2: it can support capacities of over 256gb, something StoreMi can't do without paying a lot more than $30

3: It can support multiple drives, which means I could cache both my 2tb and 4tb drive.

The thing is...and this is just my thinking...if it was this perfect, why can't I find more people talking about it on youtube? Why isn't everyone using it if it is this good? Am I missing something?

So, before I put 6 terabytes of data at risk, I felt I should ask all of y'all...is there a good reason NOT to use the random NVMe drive with primocache in this case?

Electronics Wizardy · June 28, 2020

always do a backup first, but might as well try the trial. For downsides, if you turn on the faster write modes, that can leave data at risk due to a power loss or other issues.

porina · June 28, 2020

21 minutes ago, JMSOG said:

The thing is...and this is just my thinking...if it was this perfect, why can't I find more people talking about it on youtube? Why isn't everyone using it if it is this good? Am I missing something?

I think it sits in a gap. For people who have little money, they'll just put up with HDs for bulk. If you're better off, you can go all SSD. So this kinda sits in between.

21 minutes ago, JMSOG said:

So, before I put 6 terabytes of data at risk, I felt I should ask all of y'all...is there a good reason NOT to use the random NVMe drive with primocache in this case?

You mentioned StoreMI already, which personally I felt was a higher risk option since it moved data around, not duplicating it. I found out by chance earlier this year AMD no longer offer it, and they're supposed to be bringing out a successor. Haven't heard anything more about it since though, but could be one to watch out for.