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Comment by dmix | Hacker News Reader

For those curious about high-end SSD's. I took the bait and it really wasn't worth it.

I paid $300 for a Vertex 3 when it first came out. It advertised 500MB/s up and down with SATA6.

I upgraded from one that was around 150MB/s.

I'm a developer, on my computer all day and to be honest, I rarely noticed the difference between the two.

The difference between HDD and SSD is massive. But between different SSD tiers, it's not super noticeable unless you are a heavy writer/reader for maybe something like video editting.

Kind of like 24bit music vs 16bit.

Spend the cash on size and reliability, not performance.

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To be fair, if you only look at sequential access numbers on any disk your likely to be disappointed unless you happen to have a very sequential workload, which isn't terribly common.

Loading large applications, copying large files, loading the OS, some types of video editing, etc may benefit from sequential performance but for the majority of real world workflows 4k random I/O per second is a much better metric (though certainly not universal). IO/sec is much more important in the area of dev work, database performance in particular. The current generation of SSDs are massively faster in IO/sec than older models, much greater improvement than the sequential numbers indicate. That said, you still may not notice a difference if what your doing doesn't hammers a database that is 'safe' (guaranteed consistency on disk) or if your working set doesn't outstrip the ram you've allocated to the db.

Yes yes yes.

The feeling you get from a good SSD is largely due to reduced IO latency (both read and write).

The ability to absorb random writes (to a degree) is huge too. It's why the 2008-vintage Intel X25-M caught the industry by surprise. Other SSDs at the time had extremely poor random write latencies.

Bandwidth is secondary, unless you are talking about an enterprise/database deployment (where queue depth is deep and you want great bandwidth and latency).

Pedants will note that bandwidth and latency are related (see Little's Law).

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