Wednesday, March 21, 2018

High endurance microSD card suitable for use in car dashcam

If you have a car dashcam, you will need to install a microSD card in it to store its video recording and emergency photo taking.

Even though certain dashcams come with some amount of internal memory, the storage capacity of this internal memory just won't be enough, and you probably would not like to give your whole dashcam (instead of the microSD card only) as evidence for investigation in case it really captured some critical event that happened to your car.

Most people found that the microSD card installed in their dashcam is unable to last long and will be unusable within a few months of usage. Most memory card manufacturers also exclude warranty if they found out the memory card is used in dashcam. Why? Because ordinary memory cards are not designed to be used in tough working conditions in your dashcam.

What kind of tough working conditions for the memory card to work in your dashcam, which installed right behind your car windscreen?

  • It will need to be able to endure the sunlight heat entering and developed in the car. At noon, when your car is parked in uncovered place, its cabin temperature can easily go above 35 degree Celsius (if you installed good window tint with high TSER value) , and can possibly go beyond 65 degree Celsius if your car is non-tinted and stays for long hours under hot sunlight.
  • It will need to have high number of rewrite cycles for its lifespan. As you might aware, the electronic storage cells in the memory card has limited times of data rewrite. That is also the reason whereby disk defragmenting is highly discouraged for SSD hard disk as massive data rewrite will shorten its lifespan. Whenever your dashcam is working, it will keep on recording videos into your microSD card. If you are recording 1080p videos, it just takes a few hours to completely used up a 32 GB microSD card. When the microSD card is used up, older videos will be overwritten by new records, and the rewriting will occur.

Other than the above 2 essential conditions, the memory card used in your dashcam should also meet the following conditions:
  • Shock and vibration proof - if it got damaged while writing data during accident shock, you will have difficulty retrieving what it had recorded.
  • Water proof - what if the accident caused it to immerse in water?
  • Class 10 - this is the minimum read/write speed required to smoothly record 1080p full HD video.

By the way, certain memory card manufacturers also include the following conditions, which I consider as "marketing gimmick" as it should be true for all flash memory cards:
  • Magnetic proof - metal detector used for security scanning could induce magnetic field. Don't worry, only magnetic hard disk will be endangered by magnet. Flash memory should immune to magnet by nature. So, nothing to shout about.
  • X-ray proof - x-ray is used for security scanning in airports. Flash memory should immune to X-ray as well. Nothing to shout about either.

Therefore, you need high endurance microSD card that can fulfil all of the above conditions to work in your car dashcam, to last for at least 24 months of operations, or a minimum of 5,000 hours of continuous 1080p full HD video recording.

The high endurance microSD card should have an operating temperature range of around -25ºC to 85 ºC and storage temperature range of around -40ºC to 85ºC.

Some of the available high endurance microSD cards in the market include:
  • Sandisk high endurance video monitoring card
  • Transcend high endurance MLC microSD card
  • Silicon Power high endurance MLC microSD card
  • Kingston Industrial Temperature microSD UHS-I
  • Adata Premier Pro microSD UHS-I
The price of this kind of high endurance microSD card is much higher than ordinary microSD card. Among them, Sandisk high endurance video monitoring card has a relatively lower price, being a mid-range product of its kind. It has a 2 years warranty period which would not void even you use it in your dashcam.

Sunday, March 18, 2018

My experience sharing of using Intel Optane technology accelerated hard disk

Recently I have purchased a Dell XPS 8930 desktop computer which comes with an ordinary 1 TB SATA hard disk, paired with a 16GB Intel Optane memory card.

As advertised by Intel, "the Intel Optane memory is a smart, adaptable system accelerator for PCs with at least a 7th Generation Intel Core processor and a hard disk drive. It provides uncompromising system responsiveness for large capacity storage drives, making everything you do fast, smooth and easy."

Intel has put up a short video to explain what is Optane memory about and how its Smart System Acceleration works, as below:

The main purpose of this Optane memory is to boost up the performance of ordinary SATA hard disk, which capacity is generally much higher than SSD and price is much more cheaper than SSD, so that the data access time of the Intel Optane accelerated hard disk can be comparably as fast as SSD.

I have this Dell XPS 8930 desktop with 1 TB Optane accelerated hard disk as its storage, running on Intel Core i5-8400 CPU and 8 GB memory. I also have a Dell Inspiron 5370 laptop with 256 GB SSD as its storage, running on Intel Core i7-8550U CPU and 8 GB memory. Both of them are running on MS Windows 10 operating system.

In my personal experience of using this desktop with Optane accelerated SATA hard disk which has storage capacity 4 times larger than my laptop, its boot up time is almost instantaneous and faster than my laptop. This is really amazing.

Well, to be fair, the Intel i5-8400 Coffee Lake processor in my desktop with 6 cores 6 threads processing power, is having a higher performance benchmark than the Intel i7-8550U Kabe Lake R processor in my laptop with 4 cores 8 threads processing power. This would probably explain why the desktop boot up time is faster than the laptop. However, without the acceleration of Optane memory, its boot up time with SATA hard disk will be much more slower.

As for the loading speed of applications in the desktop, and the speed of opening data files, it depends on whether they have already been cached in the Optane memory or not. I can feel that their loading speed is about the same with loading from SSD when they are cached, and is as slow as loading from SATA hard disk when they are not cached.

There is no mechanism for me to control which piece of data to be cached and which not to be cached. It is automatically determined by the Optane memory card itself. I can tell from experience that those frequently used one will stay in the cache and load up pretty fast.

Intel provides 2 options of Optane memory capacity, one is 16 GB and another is 32 GB. I think the 32 GB one is of better pick as it has double the caching capacity. However, the Dell XPS 8930 selling in Malaysia does not provide option for buyer to opt for 32 GB Optane memory, as only 16 GB Optane is available.

All in all, I am happy with the performance of this Intel Optane memory in my desktop computer. The only drawback is that current Intel Optane technology does not support RAID storage. It can only work with raw SATA hard disk.

I haven't have experience in using SSHD hybrid hard disk. Perhaps the experience is similar. I am also wondering what makes the different of using Optane memory with SATA hard disk from using SSHD.

Thursday, March 15, 2018

How to determine a good car window tint film from TSER, UVR and VLT values?

The performance of car window tint film is generally determined by these 3 values:

  • TSER - Total Solar Energy Rejected. This is the overall solar energy filtered by the film. The higher the TSER, the more heat from sun is blocked from entering into your car through its windscreens and windows.
  • UVR - Ultraviolet Rejection. Ultraviolet rays can cause colour fading in upholstery and furnishings. It can also cause skin damage and skin cancer.
  • VLT - Visible Light Transmission. This is determined by the darkness of the film. The darker the film, the lower its VLT will be. Note that JPJ has regulation for the minimum amount of VLT allowed for the tint film, so the VLT need to be equal or above the permitted value to abide to the regulation imposed. As VLT contributes quite a large portion of TSER, it will affect the TSER value pretty significantly.

Traditionally, many tint shops tend to use IRR (infra-red rejection) as an indicator, but the infra-red wavelength spectrum is very long and there is no standard of how much of the spectrum to be used to measure IRR, some products claim to have high IRR by measuring only a short portion of it right after the visible light spectrum, which does not have much meaning for the real heat rejection performance measurement. Therefore, unless the wavelength spectrum of IRR is clearly specified and the measurement is until 2,500 nm or more, otherwise this value can be neglected as TSER can provide a more meaningful value for consideration.

So, how to determine a tint film is good, moderate or poor, based on its TSER, UVR and VLT values?

First we look at VLT value, as it's minimum requirement is regulated in Malaysia. A good VLT value should be as low as possible (so that the TSER value will also be lower) but should not go below the JPJ standard. Otherwise, the enforcement officer may ask you to remove your tints from your windows due to violation of this regulation.

The minimum allowed VLT currently imposed by JPJ is as follow:
  • Front windscreen: 70%
  • Front side windows: 50%
  • Rear side windows: 30%
  • Rear windscreen: 30%

The MS2669:2017 standard has set the requirements for tint film for the following 3 tests:
  • Solar test: VLT, UVT (opposite of UVR) and TSET (opposite of TSER).
  • Weathering test: TSET/TSER value should be stable for a period of 5 years with less than 4% degradation. This is simulated with 1,000 hours shining from solar mercury lamp.
  • Boil test: the tint film should not form bubbles under high temperature.

With reference to this MS2669:2017 standard, we can then determine the range of TSER and UVR which is considered to be good, moderate or marginal only.

  • Good: > 50%
  • Moderate: 39% - 49.99%
  • Marginal: 25% - 38.99%
  • Failed: below 25%

  • Good: > 99.5%
  • Moderate: 98.5% - 99.49%
  • Marginal: 98% - 98.49%
  • Failed: below 98%

Therefore, if you are looking for a good car window tint firm, you can look for those that meet the following realistic requirements:
  • TSER: 56% - 62%
  • UVR: 99.5% - 99.9%
  • Front windscreen VLT: 70% - 75%
  • Front side windows VLT: 50% - 60%
  • Rear side windows VLT: 30% - 50%
  • Rear windscreen VLT: 30% - 50%

Hint: Click on the "Older Posts" link to continue reading, or click here for a listing of all my past 3 months articles.