Opinions on using an SSD for recordings

[cliveb]

I've seen a number of postings from people who use SSDs for their Myth backends.
My use of MythTV is as a time shifting DVR - recording OTA broadcasts, watching and then deleting.
I don't archive recordings long term. Therefore my use involves a lot of write cycles, and until now I'd always believed that was not good for SSDs.
But maybe I'm out of touch with how modern SSDs operate.
The advantage of using an SSD instead of HDD would be the lower power consumption and zero noise.
Any thoughts?

[bill6502]

I use spinning rust for all recordings. Just my 2¢.

[Gribnif]

My understanding is that the limit on write cycles in modern SSDs is pretty high and if a block becomes unwritable the firmware just takes one from its pool of extra blocks and uses that instead. Furthermore, if blocks do start to go bad, they will appear in the SMART reporting, so you know in advance if you're starting to have problems. While an SSD can of course fail catastrophically just like an HDD can for other reasons, hitting the write limit won't immediately cause a large number of blocks to become unusable.

That said, it's certainly still cheaper to use an HDD, even when you factor in the additional energy use.

[cliveb]

Thanks for the responses.
I asked on another forum and the resident hardware expert there confirmed that using SSDs for write-intensive applications isn't generally a good idea.
So I think I'll stick with HDDs for now.

[nouglywires]

I built a new MythTV box a couple of years ago with an SSD, fast (Intel J5040) fanless motherboard, fanless PSU. Power consumption at the wall outlet is 4-12W.

I just checked the SMART data for the SSD:
16,608 power-on hours.
12,336,792,952 LBAs written.
0 errors in all categories: read, write, CRC, ECC, erase fail, program fail, read retry, etc etc
Endurance (% lifetime remaining): 100%.

The response to remote button presses is absolutely instantaneous. You can hop back or forward as fast as you can press the button. It's a perfect viewing experience.

[seerozha]

I just upgraded an old Ubuntu server laptop from a spinning to a SSD disk, paid less than $30 for 500GB of disk and after running diagnostics it’s 5x faster on sequential reads. Storage is dirt cheap and performance improvement is tremendous.

[kmdewaal]

I use since more than a year 2x8TB SSD for recording. I expect this to live practically forever, but also because the disks are quite big relative to the amount of daily recording. When the SSD is twice as big it will last twice as long, that is the big idea. I do have had SSD failures of the type "sudden death" but I have not yet seen an SSD die of old age or too many bytes written. My 2 cents...

[white_haired_uncle]

I use 4TB RAID1 pairs of rust, and will do so for the forseeable future (4TB is big enough that a resync takes as long as I care to put up with, and rust is not going to get any faster). The drives are in an otherwise unused room (no drives in the FE) so I don't have to listen to them. Since they run a bit over 100x the speed of the highest bitrate HD recording anyway, throughput is acceptable since I rarely watch more than a few dozen TVs at once. The application resides in memory, so no issue there. Saving a ms or two when starting playback sure sounds nice, but by the time SSD is comparable in price (which will happen FOR ME, since I won't use >4TB HDD and eventually those will become pretty rare) I'll probably be too old to notice a ms here or there.

As far as SSDs wearing out, while I'm too lazy to do the math I can't see it being much of an issue. Yes, recording TV does write a lot of data (potentially only read once) compared to most other apps, but it also does so VERY SLOWLY.

[madprofessor]

I use since more than a year 2x8TB SSD for recording. I expect this to live practically forever, but also because the disks are quite big relative to the amount of daily recording. When the SSD is twice as big it will last twice as long, that is the big idea. I do have had SSD failures of the type "sudden death" but I have not yet seen an SSD die of old age or too many bytes written. My 2 cents...

Yeah, totally agreed on the size vs lifetime thing.

When I worked at an ISP we had 3 file servers for email with customer mailboxes spread across them. We had previously had spinning drives but they couldn't keep up with the I/O so they got replaced with SSDs.

I was actually expecting them to die pretty quickly due to the write intensity (this was back when POP3 was the main thing, so most of the data was written once and read once, then deleted).

But to everyone's surprise the SSDs lasted several years without any hint of issue, then the company was bought out and I had nothing more to do with it.

The SSDs were probably running (finger in the air guess) around 60 - 70% full, with the write once -> read once -> delete cycle that was knobbling the spinning drives.

And this was at least 15 years ago ... SSD tech has moved on a lot since.

And yes, as others have said, they can fail. We had one fail under warranty a couple of years back. It's times like that when you're thankful of RAID.