Hardware: Difference between revisions

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* The copy-paste speed on my 7200rpm hard disk is about 160MB/s.
* The copy-paste speed on my 7200rpm hard disk is about 160MB/s.
* [http://www.androidcentral.com/weekend-project-diy-usb-go-old-cables DIY USB on the go cables].

Revision as of 22:23, 18 January 2014

  • My own collection
Device Family Instruction Clock & Memory
Pogoplug ARM9 ARMv5 1.2GHz, 256MB
Raspberry Pi ARM11 ARMv6 700MHz, 512MB
Beaglebone Black Cortex A8 ARMv7 1GHz, 512MB
UDOO Cortex A9 ARMv7 1GHz, 1GB

See wikipedia for a list of ARM cores. These SoC are 32-bit. The newest ARM architecture is ARMv8 which is 64-bit; see here.

  • Samsung pico DLP projector sp-h03 LED, 30 ANSI lumen 854x480, 12V & 1A power. The manual is available at Samsung web site here. The input signal in D-Sub can be 1280x800, 1280x768, 1280x720 resolution although the manual also said "All resolutions higher or lower than 854 x 480 are converted to 854 x 480 by the scaler chip in the projector. To obtain an optimal picture, the resolution from the PC should be similar to the projector (854 x 480)".
  • USB device speed comparison
Device Read Write FS
MicroCenter4G Example 12.77MB/s Ext3
MicroCenter4G Example 5MB/s vfat
Patriot XT 32G USB3.0 Example 50MB/s vfat
Patriot XT 32G USB3.0 Example 115MB/s fat16
Patriot XT 32G USB3.0 Example 113MB/s fat32
Patriot XT 32G USB3.0 Example 24MB/s ntfs
Patriot XT 32G USB3.0 Example 139MB/s ext2
Patriot XT 32G USB3.0 Example 50~100MB/s ext3
Patriot XT 32G USB3.0 Example 140MB/s ext4
Example Example Example vfat

When testing Patriot XT USB 3.0 drive, I partition it into ext2 (15GB)& ext3(15GB). The problem of unstability in Patriot XT's ext3 partition is not related to ext3 partition because if I switch the order of partitions of ext2 and ext3, then ext2 becomes unstable.

  • A word about USB flash drive.
    • According to the Slo Bytes USB Flash Drives report from Brian K. Lewis, flash drives are capable of handling 10 thousand to 10 million write and erase operations during their lifetime, depending on the source as well as the specific USB drive. Regardless, a flash drive typically will outlast any standard hard drive. The main concerns about the life expectancy of a flash drive are damage from neglect and becoming lost or stolen.
    • The life expectancy of a USB Flash Drive can be measured by the number of write or erase cycles. USB flash drives can withstand between 10,000 to 100,000 write/erase cycles, depending on the memory technology used. When the limit is reached, some portion of the memory may not function properly, leading to lost of data and corruption.
    • Most experts would agree that around 10 years is about what you can expect to retain data on a flash drive without powering it up. That means you can lock away a USB drive for 10 years and return to still see your data. After 10 years of not being powered on, the electrical charges determining if bit of information is either a ‘1’ or a ‘0’ gets hazy. This is because like all electrically charged devices, they suffer from what is called electro/magnetic deterioration; or simply put, where devices will eventually lose their power.