Monday, August 15, 2016

Updated USB Specifications

Last week was spent updating the VIUD specifications on the new store site which includes a number of values related to the USB (read on for an explanation of each benchmark):

16 GB 32 GB 64 GB 128 GB 256 GB
Usable Capacity
15,961,546,752 bytes
31,651,479,552 bytes
62,911,414,272 bytes
125,818,503,168 bytes
253,121,003,520 bytes
File System
HD Tune Pro Benchmarks
106.5 - 116.7 MB/s
114.2 - 127.9 MB/s
119.9 - 130.7 MB/s
181.2 - 193.3 MB/s
56.0 - 146.8 MB/s
Average Read
111.7 MB/s
121.9 MB/s
123.5 MB/s
187.7 MB/s
142.1 MB/s
Access Time
0.889 ms
0.973 ms
1.16 ms
0.747 ms
0.811 ms
Crystal Disk Mark Benchmarks
Read Seq Thread
121.6 MB/s
130.1 MB/s
133.3 MB/s
208.8 MB/s
149.2 MB/s
Read Rnd Thread
16.4 MB/s
14.3 MB/s
14.1 MB/s
6.03 MB/s
22.1 MB/s
Read Seq
119.8 MB/s
127.6 MB/s
131.6 MB/s
205.4 MB/s
146.6 MB/s
Read Rnd
15.0 MB/s
13.3 MB/s
13.6 MB/s
5.47 MB/s
19.2 MB/s
Write Seq Thread
24.2 MB/s
34.8 MB/s
38.2 MB/s
132.5 MB/s
94.1 MB/s
Write Rnd Thread
0.051 MB/s
0.097 MB/s
0.69 MB/s
0.224 MB/s
1.37 MB/s
Write Seq
22.4 MB/s
25.6 MB/s
17.8 MB/s
129.8 MB/s
22.6 MB/s
Write Rnd
0.054 MB/s
0.055 MB/s
0.81 MB/s
0.0048 MB/s
1.07 MB/s
USBFlashBench Benchmarks
116.70 MB/s
124.93 MB/s
127.54 MB/s
206.48 MB/s
131.13 MB/s
22.72 MB/s
29.40 MB/s
32.89 MB/s
133.83 MB/s
55.93 MB/s
4GB File Copy
2:38.3 (24.1 MB/s)
1:49.5 (34.8 MB/s)
1:42.1 (37.3 MB/s)
0:30.2 (126.3 MB/s)
0:44.8 (85.2 MB/s)
0:33.4 (114.1 MB/s)
0:31.2 (122.1 MB/s)
0:30.6 (124.6 MB/s)
0:18.4 (206.9 MB/s)
0:28.8 (132.7 MB/s)

The VIUD's usable capacity is slightly less than the stated capacity which is typical of just about any mass storage device. Part of the overall device's drive space is taken up by the file allocation table which takes more space on larger drives. The other part, however, is just due to the USB board manufacturer using a slightly smaller size than stated. Perhaps this is due to a technical reason or, more likely, an economic one.

HD Tune Pro is a basic disk benchmarking and testing application. Unfortunately the write tests don't seem to work on newer operating systems but the read and error tests do give a nice visual display. I'd like to point out the low minimum read speed for the 256 GB VIUD which can be easily seen in the following graph:

VIUD 256 GB HDTunePro Read Benchmark
All other VIUD capacities have a roughly flat graph for the blue line but the 256 GB model has much slower read speeds at exactly 32 GB intervals for whatever reason.

CrystalDiskMark is another basic drive benchmarking tool that outputs several read and write tests:
  • Seq Thread = Sequential read/write, 128 KB block size with multiple queues and threads
  • Rnd Thread = Random read/write, 4 KB block size with multiple queues and threads
  • Seq = Sequential read/write, 1 MB block size with single thread
  • Rnd = Random read/write, 4KB block size with single thread

USBFlashBench is a simple tool that tests multiple block read/write sizes and then uploads the results to a website and creates nice graphs like:

USBFlashBench Results for the 256 GB VIUD
Finally, the 4GB file copy test is simply the time it takes to copy a 4 GB (4,000,000,000 bytes) file composed of random content to the VIUD and the time it takes to read it back. Due to caching we have to make sure to unplug the VIUD after the write test and then plug it back in to do the read test.

Tuesday, August 9, 2016

Product Shots!

Work on creating the VIUD store started last week and I'm already well on my way to getting it finished. I decided to go with Shopify as it seems to be a good sized Canadian online e-commerce system with the features I need.

I've spent the better part of the last week taking and preparing product shots of all the various VIUD models for use in the store. There are a lot of good online guides for taking product shots but to summarize what I've used:

  • Niken D90 camera with SB-600 flash
  • Small light tent
  • Piece of white paper over the flash to disperse flash and soften shadows
  • A few extra lights to get better shadow and reflections (some "real" camera lights would be very nice but I've made do)
  • About half-zoomed in on the lens
  • Auto color balance on the camera
  • Manual mode on the camera with a high aperture (F20) for a larger depth of field
  • Adjust the exposure time and bias to get a good picture (white background without too much shadow)
  • Adjust the picture's brightness, contrast, and saturation afterwards to get a realistic and good looking image

The shots turned out pretty good and I think they can speak for themselves!

Wednesday, August 3, 2016

Getting Closer...

So my summer vacation is unfortunately over and I'm getting back into the finishing stages of the VIUD preparation. All I can do before actually selling them is to do the coating of all the USB boards I currently have.

Through all the various testing I've done, mainly the shock testing, I've narrowed down a good combination of coatings and epoxies that seems to maximize the durability of the USB. I start with two layers of Silicon conformal coating.

Silicon Conformal Coating a USB

This is thin, flexible coating that gets into all the small nooks and crannies on the circuit board and even by itself seems to help a lot in minimizing damage caused by shock. Each coat requires at least a day to dry out.

Drying Out the Conformal Coating

Once the two conformal coatings are dry it is time for another two coatings of a thicker and more flexible insulating coating.

Coating a USB in Insulating Varnish
This gives the USB circuit board a considerably thicker and flexible coat to help absorb even more shock. It also helps prevent epoxy from leaking through the USB connector and making a considerable mess which is difficult and time consuming to clean up. Like the conformal coating each insulating coating takes a day to dry.

Drying Out the Insulating Coating

Next step is to just create an online store and actually start selling things!