News for hackers. Stuff that matters.

A comment on Intel’s first Optane SSD: 375GB that you can also use as RAM.

Re:Intel’s first Optane SSD: 375GB that you can also use as RAM by Animats on Monday March 20, 2017 @02:30AM (#13912188)
The big limitation of this device is wear. "Optane SSDs can safely be written 30 times per day", says the article. That implies a need for wear monitoring and leveling. Although you can modify one byte at a time, the need to monitor wear implies that just memory-mapping the thing isn't going to work.

Wear management could be moved to hardware, though, using a special MMU/wear monitor/remapping device. If you're using this thing as a level of memory below DRAM, viewing DRAM as another level of cache, something like that would be necessary. That's one application.

This device would make a good key/value store. MongoDB in hardware. Then you don't care where the data is physically placed, and it can be moved for wear management.

[ Parent | on HN ]
Re:Intel’s first Optane SSD: 375GB that you can also use as RAM by pilif on Monday March 20, 2017 @02:47AM (#13912238)
From the article:

> This gives the drives much greater endurance than NAND of a comparable density, with Intel saying that Optane SSDs can safely be written 30 times per day, compared to a typical 0.5-10 whole drive writes per day.

I understand this as: to get normal length usage of traditional SSDs you can get away with writing enough data to completely rewrite the device 0.5 to 10 times, whereas with the new device, it's 30 times.

The new technology is 3 times better than SSDs with regards to write durability.

I think the article would be better worded if it didn't leave out the most important number: 10 rewrites per day for how long before either the SSD or the new thing fails?

[ Parent | on HN ]
Re:Intel’s first Optane SSD: 375GB that you can also use as RAM by viraptor on Monday March 20, 2017 @03:07AM (#13912320)
It doesn't say that the wear leveling is not present inside the box already. It could mean rewriting the whole storage 30 times a day effectively.
[ Parent | on HN ]
Re:Intel’s first Optane SSD: 375GB that you can also use as RAM by Animats on Monday March 20, 2017 @12:52PM (#13915669)
If writes can be done at the byte level, the bookkeeping and indirection for byte level wear leveling would take more space than the data. If wear leveling is required, it has to be done on blocks of some reasonable size. They might be smaller than for flash, though.
[ Parent | on HN ]