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Comment by duskwuff | Hacker News Reader

> hard drives can keep farming forever

SSDs have limited program/erase lifespan, and the proof-of-space algorithms used by Chia eat into that lifespan pretty fast.

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To be precise, the process of "plotting" (using disk space for Chia) causes a lot of writes to disks, but those writes are a one-time process. Once a plot is written it can be moved anywhere and farmed forever. The actual proof of space algorithm for farming only takes an initial 5 seeks and then 64 seeks for the full proof so farming is not a big stress on disks long-term.

What numbers are we talking about here? Assuming 1tb ssd with say 1000 cycles of warranty, would it die instantly or would it not even feel it?

do you need to use ssds with chia?

No, it's just useful to use SSDs for plotting since they're faster. For farming any storage (HDDs, for example) are fine.

How about a RAM disk?

Sure but you need about 300GB RAM for the temporary files needed while creating plots.

Thinking about it, for someone who is looking to be seriously into chia, that might make sense. The cost of the RAM is only about $1,500. Might be a smart idea.

Has anyone tried this? Would be interesting to see the benefits.

Wouldn't the ram be idling most of the time while farming? Only storage space matters for farming, speed doesn't.

Honestly, this part I don't understand.

Somewhere over that couple days I read that you can farm on an HD, but plotting is faster on an SSD, so I'm making a huge presumption that plotting on a ramdisk would be even faster, without the wear on an SSD.

I'm still not clear on Chia. Sometimes I think I understand it, and other times I'm not so sure...

Plotting is the initial process of building the files that you farm with. Plotting is very CPU/Memory/Disk IO intensive and the total writes to a disk to build a ~100gb plot is over 1tb with ~260gb of temporary space used at any one time during the process. This means that the process of building plots (plotting) is best done with an ssd. The fact that the process writes over 1tb to the disk to generate a ~100gb plot means that you will be really consuming the life of a consumer grade SSD with a low TBW rating. It is possible to use RAMDisk and yes it is potentially faster for a single plot. But you would need ~260gb of ram to plot 1 plot at a time. Nvme SSD's are only marginally slower than ramdisk but they are much cheaper per GB and you can connect multiples of them meaning you can build many plots at once. ie. 1-2 plots per CPU core concurrently provided you have sufficient ram ~3400mb per plot and sufficient fast temporary storage SSD. Once plotted the plot file can be moved to a spinning disk HDD and farmed from there as very little reads are ever made in the farming process. Can you use Ramdisk? yes. Is it better? No. It's far cheaper and faster to use SSDs and use your ram for building multiple concurrent plots.

Thank you very much. That’s the first explanation that makes complete sense.

Actually plotting in parallel across multiple SSDs is likely to have the highest TiB/day of plots created. And then you’d be better off using the ram to enable more parallelism.

It’s a matrix of processor cores, threads per core, temp drive bandwidth, memory, and temp drive speed. Oh and cost per TiB of plots per day.

Also plotting happens in several stages, and each has a different set of requirements. So timing the running of plots in parallel and staggering starts also comes into it.

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