Posts by technovelist

Japanese space lasers aim to clean up orbital junk

"Japanese"

Just here for the MTG references.

Why the end of Optane is bad news for all IT

Re: You know mmap is a thing right?

Yes, you can memory map the Optane DIMM storage into memory. In fact that's the only way to get direct access without time penalties.

The good news is that both Linux and Windows do this very well. Even if you are running a Hyper-V Linux virtual machine you get direct access to the underlying storage.

A valid use case for Optane DIMMs

First of all, a lot of people here are confusing the Optane SSD, which of course has an SSD interface, with Optane DIMMs, which were the truly revolutionary advance.

The SSD was very fast for an SSD, around 5-10 microseconds per access, but obviously that is several orders of magnitude slower than RAM and can be accessed only in pages of 4k.

The Optane DIMM was a different animal entirely, even though the underlying medium was the same phase-change storage in both cases.

Optane DIMMs have read access times on the order of 150 nanoseconds, not too much slower than DRAM if we are talking about enormous amounts of data where the page tables have to be traversed to figure out the physical address.

The use case I'm referring to is a gigantic hash table. I'm currently working on building a trillion record hash table occupying 8 TB of Optane DIMM storage, with the ability to read millions of random records a second, all on one machine. Of course it is also persistent, so you can build it once and process it with whatever programs you want later.

This isn't possible with any other commercial technology.

Rust can help make software secure – but it's no cure-all

Re: "Rust will stop you using data after it's been freed"

"A real programmer can write FORTRAN in any language" -- anonymous

Revealed: The 25 most dangerous software bug types – mem corruption, so hot right now

My rule is never to use raw pointers other than in library classes that manage the data and lifetimes thereof. Application code should not use them.

Re: Airbags

C++ is not to blame for the fact that a lot of people are unable to write good C++ programs. It is certainly possible to do so, and it can provide performance that is unavailable in "safe" programming languages.

So if you aren't a very good programmer, maybe you should use another language... or learn to be a better programmer. But blaming C++ isn't going to help.