[Leica] Help with understanding the new SSD in my computer.....

[Spencer Cheng]

Frank,

It all depends on your usage. Disk throughput is limited by 2 factors. One is the interface speed (SATA usually, 6 Gb/s). This is not usually an performance limitation.

The other more important factor is how fast the data you want can be found on the disk and pulled off the the disk. With HDD, there is an average latency of 12.5ms (depending on HDD spin speed) because it takes on the average 1/2 of a rotation to to find the data on the disk. The data is then pulled off the disk.

Data transfer speed from a consumer HDD usually will NOT exceed 150MB/s but the real performance killer is the 12.5ms seek latency.

An SSD usually hit about 300 MB/s or better transfer speed with basically no seek latency. [There is some “seek” latency but it’s a few hundred microseconds rather than 12.5ms]

12.5ms doesn’t sound very long but multiply that by hundreds of times per second.

Install your O/S and LRCC on the SSD (including swap space) plus as much of your data as you can fit on the SSD. You should see considerable performance difference.

My old MacBook Air comes with an SSD but a super wimpy CPU. Most of the time I never noticed the CPU was so slow because the SSD was fast as compensation.

Regards,
Spencer

> On Jul 26, 2017, at 11:19, Frank Filippone <red735i at verizon.net> wrote:
> 
> The top line is that the new SSD  is no faster than my HDD, as tested by
> LRCC.
>