Currently Viewing Posts Tagged faster

Wifi Standard 802.11ac

802.11ac is main stream as well as 802.11n.

Because 802.11n has better distance and more power to pass-through wall. But 802.11ac is much fast than 802.11n.

802.11ac Technology Overview:

11n Specification:

  • 2.4 and 5Ghz¬† Supported
  • Wider channels 40MHz
  • Better modulation 64QAM
  • Additional streams up to 4 streams
  • Beam forming
  • Backwards compatibility, with 11a/b/g

11ac introduces:

  • 5GHz supported
  • Even wider channels 80Mhz and 160 Mhz
  • Better modulation 256 QAM
  • Additional streams up to 8
  • Beam forming
  • Backwards compatibility with 11a/b/g/n

Wider Channels:

80MHz channels is 4.5x faster than 20MHz

 

Now 802.11ac v2 is comming. Also called wave 2. It is expected to be available in 2015.

Here is some highlights of wave 2 802.11ac.

MU-MIMO

  • Use AP MIMO resources more effectively
  • Transmit data to multiple devices simultaneously.

4×4:4SS

  • Benefit of additional stream mostly for MU-MIMO
  • Not anticipating any 4×4:4SS client devices
  • Adds 33% to max datarate

VHT160

  • Double s max datarate
  • Practical problem: only 2 VHT160 channels in entire 5GHz band

Continue reading “Wifi Standard 802.11ac”

Replace PHP 5.3.3 by PHP 5.5.3

I have a test before to compare the performance of PHP 5.5 and PHP 5.3. The result is PHP 5.5 is 20% faster.

Now, I replaced PHP 5.3.3 by PHP 5.5.3 at this server, which my blog is on.

The php -v information shown as below:

PHP 5.5.3 (cli) (built: Aug 24 2013 10:14:23)
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies
with Zend OPcache v7.0.3-dev, Copyright (c) 1999-2013, by Zend Technologies

Continue reading “Replace PHP 5.3.3 by PHP 5.5.3”

  • Archives