Re: [boost] NuDB: A fast key/value insert-only database for SSD drives in C++11

Subject: Re: [boost] NuDB: A fast key/value insert-only database for SSD drives in C++11
From: Asbjørn (lordcrc_at_[hidden])
Date: 2017-03-27 11:29:18

On 27.03.2017 01:14, Niall Douglas via Boost wrote:
>
> Your hash function (which runs per thread) only needs to be as fast as
> your storage device is at a queue depth of 1. So, taking a top of the
> range NVM SSD, the Samsung 960 Pro, it can write at QD1 about 50k IOPS.
> That's around 200Mb/sec/thread. Blake2b runs at 1Gb/sec, so it should
> comfortably fit with a bit of room to spare on a single thread.
 >

I'm probably being dense, but I don't get your argument. NuDB hashes the value 
to use as a key, from what I understood. If you have a large value, the write 
will be much faster than with random 4k IOPS, no?

For reference, on my i7 4770k running Win 8.1 a 1TB 960 Pro has about 1700MB/s 
sequential write speed and 150MB/s 4k random write, both at QD1.

Cheers
- Asbjørn