Archived posting to the Leica Users Group, 2017/07/26

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] Help with understanding the new SSD in my computer.....
From: spencer at aotera.org (Spencer Cheng)
Date: Wed, 26 Jul 2017 19:13:41 -0400
References: <009501d30622$985eca00$c91c5e00$@verizon.net>

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.
> 



In reply to: Message from red735i at verizon.net (Frank Filippone) ([Leica] Help with understanding the new SSD in my computer.....)