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How to improve SSD read/write performance

See this guide.

SSD benchmark utilities

  1. AS SSD Benchmark
  2. CrystalDiskMark

Restore write performance of SSD drive using secure erase

A Secure Erase is issued against a SSD drive all its cells will be marked as empty, restoring it to factory default write performance.

Here is the guide to secure erase a disk.

How to secure erase your hard drive (HD/SSD)

1. Use HDDErase
  • Download the HDDErase software and burn the iso file into a CD. and boot the computer from that CD. then run HDDErase.
  • You can also download and burn UBCD, which includes HDDErase.
  • Here is the guide to use HDDErase
  • HDDErase does not support all the motherboards/disks. You may need to look at method 2: use hdparm
  • this method can be used to restore write performance of a SSD disk.
2. Use hdparm
3. Use cat
  • Linux command cat can do the work too. It may take longer time than method 1 & 2 since is an software based method not using ATA firmware functions.
    sudo cat /dev/zero /dev/sdx
    

    where /dev/sdx is the disk to be erased.
  • This method can be used to restore write performance of a SSD disk though it will be slower than HDDErase or hdparm. Here is the post discuss this.
4. Use Darik's Boot And Nuke

Note: HDDErase and hdparm uses ATA's firmware functions to secure erase the disk. They are recommended to be used to restore the write performance of a SSD disk.

See also

How to enable Status Bar in Firefox 4

It is not as convenient as earlier versions since the status bar has been removed in Firefox 4. You have to install "Status-4-Evar" addon to enable it.


Status-4-Evar aims to bring back (some of) the old status bar items, give you more control over the built-in Firefox features, and provide new alternatives.

The extension provides "Status Text", "Progress Meter", and "Download Status" items. These toolbar items can be moved wherever you want by customizing the toolbars. Behavior of the toolbar items, and other additional settings, can be controlled in the extension preferences.

Enable dark background for Eclipse (Eclipse Color Themes)

1. Pick and download the themes from http://www.eclipsecolorthemes.org/
2. Follow this instruction to import or install: http://www.eclipsecolorthemes.org/?view=how-to-use

Fix Firefox 4 blur font problem

1. input about:config in the address bar.
2. search for gfx.direct2d.disabled, double click to set it to true.

how to remove ubuntu firefox modifications

sudo aptitude purge ubufox xul-ext-ubufox

How to make an image darker or lighter (useful when creating icons)

Sometimes we want to make the image darker or lighter to create mouse over image or diabled image.

Here is how we can do it using GIMP:



You can get to this tools in several ways:
  • In the image menu through ToolsColor ToolsLevels.
  • In the image menu through ColorsLevels.
  • By clicking on the tool icon in the toolbox if this tool has been installed there. For this, go to Tools Dialog.
Detail: http://docs.gimp.org/en/gimp-tool-levels.html

Windows 7: boot fix

Here is the tutorial.

Windows 7 license key works both 32 bit and 64 bit

windows 7 license key works on both 32 bit and 64 bit

OCZ Vertex 2 120GB SSD: cold boot cannot detect the drive

Got a OCZ Vertex 2 120GB SSD 2.5inch SATA for my Dell Vostro V130. Installed Windows 7 from external DVD drive and it works fine until the computer is turned off. When I tried (cold) start the computer, error occurs: "Reboot and select proper boot device, or insert boot media in selected boot device and press any key."

And if I Ctrl+Alt+Del to warm reboot the computer, the windows 7 starts without any problem. Then I realised that the cold start/boot cannot detect the OCZ Vertex 2 SSD drive until I do the warm reboot.

Google and found this is an known problem for OCZ SSD opened from Nov/2010 and has not been fixed.  The only hope is that the new firmware can fix it. It looks like hopeless though.

Only conclusion: I should never buy OCZ disks.

Update: change to IDE mode instead of AHCI mode, the cold boot can detect the drive and start the OS successfully. However, you need to reinstall the OS and the performance in IDE mode is a bit lower than AHCI mode.

Update2: new problem: lost all the changes when the computer is cold rebooted. Open a thread in OCZ forum. Have not got solution yet. 

Update3: the SSD is completely dead. Cannot be recognised by any computer. If it is connected, the computer cannot start. Have to return to the store for a replacement.

Disable / Enable touchpad on Dell Vostro V130

Fn + F6

Note: you need to install Dell Touchpad driver for Vostro V130. The universal synaptics touchpad driver does not support the shortcut key combo above. However the current Dell touchpad driver has a bug, the touch pad stops working after while when the system starts. So I am using the synaptics driver ATM and waiting for Dell's driver update.

Parsing URL to get the file name

e.g. I want to parse to get the file name, 1.txt, from the url: file:/home/wilson/Desktop/1.txt
public static String getFileName(String url) throws MalformedURLException {
  URL u = new URL(url);
  String path = u.getPath();
  if (path != null) {
   String[] tokens = path.split("/");
   return tokens[tokens.length - 1];
  }
  return null;
 }


See also: Parsing a URL

孕妇忌食

容易流产食物:

1、螃蟹

它味道鲜美,但其性寒凉,有活血祛瘀之功,故对孕妇不利,尤其是蟹爪,有明显的堕胎作用。

2、甲鱼

虽然它具有滋阴益肾的功效,但是甲鱼性味咸寒,有着较强的通血络、散瘀块作用,因而有一定堕胎之弊,尤其是鳖甲的堕胎之力比鳖肉更强。

3、薏米

是一种药食同源之物,中医认为其质滑利。药理实验证明,薏仁对子宫平滑肌有兴奋作用,可促使子宫收缩,因而有诱发流产的可能。
4、马齿苋

它既是草药又可作菜食用,其药性寒凉而滑利。实验证明,马齿苋汁对于子宫有明显的兴奋作用,能使子宫收缩次数增多、强度增大,易造成流产。

对胎儿有害的食物

5、罐头食品

罐头食品在制作过程中都加入一定量的添加剂,如人工合成色素、香精、防腐剂等。尽管这些添加剂对健康成人影响不大,但孕妇食入过多则对健康不利。另外,罐头食品营养价值并不高,经高温处理后,食物中的维生素和其他营养成分都已受到一定程度的破坏。  

6、菠菜

人们一直认为菠菜含丰富的铁质,具有补血功能,所以被当做孕期预防贫血的佳蔬。其实,菠菜中含铁不多,而是含有大量草酸。草酸可影响锌、钙的吸收。孕妇体内钙、锌的含量减少,影响胎儿的生长发育。

7、巧克力和山楂

过多食用巧克力会使孕妇产生饱腹感,因而影响食欲,其结果是身体发胖,而必需的营养却缺乏。孕妇较喜欢吃酸东西,山楂便成了首选果品。山楂对子宫有兴奋作用,孕妇过食可使子宫收缩,导致流产的可能,故要少吃。

8、猪肝

芬兰和美国已向孕妇提出了应少吃猪肝的忠告。  

因为在给牲畜迅速催肥的现代饲料中,添加了过多的催肥剂,其中维生素A含量很高,致使它在动物肝脏中大量蓄积。孕妇过食猪肝,大量的维生素A便会很容易进入体内,对胎儿发育危害很大,甚至会致畸。

9、久存的土豆

土豆中含有生物碱,存的越久的土豆生物碱含量越高。过多食用这种土豆,可影响胎儿正常发育,导致胎儿畸形。当然,人的个体差异很大,并非每个人食用后都会出现异常,但孕妇还是不吃为好,特别是不要吃长期贮存的土豆。

10、热性作料

孕妇吃热性作料小茴香、八角、花椒、胡椒、桂皮、五香粉等 容易消耗肠道水分,使胃肠分泌减少,造成肠道干燥、便秘。发生便秘后,孕妇必然用力屏气解便,使腹压增加,压迫子宫内的胎儿,易造成胎动不安、早产等不良后果。

11、味精

味精的主要成分是谷氨酸钠,血液中的锌与其结合后便从尿中排出,味精摄入过多会消耗大量的锌,导致孕妇体内缺锌。而锌是胎儿生长发育之必需品,故孕妇要少吃。

12、桂圆、荔枝

性温热易致胎热;

13、石榴

贫血者要少吃.

14、腌制酸菜

含有亚硝胺,可导致胎儿畸变。

15、西瓜

每天吃水果不宜超过250g,限量吃西瓜,因为西瓜是利尿剂,容易造成孕妇脱水。  

16、饮浓茶

英国的一位医生发现茶叶中含有不少氟化物成分,一杯浓茶中氟化物含量可达1.25毫克。如果用来喂养孕鼠,则发现所生小鼠有骨骼方面的畸形,氟对胎儿的危害虽然尚未肯定,但还是不饮浓茶为好。孕期饮浓茶,不仅易患缺铁性贫血,影响胎儿的营养物质供应,由于浓茶内含有咖啡因,还会增加孕妇的心跳和排尿次数,增加孕妇的心脏和肾脏负担,有损母体和胎儿的健康。

17、饮咖啡和可乐型饮料  

咖啡和可乐的主要成分为咖啡因、可乐宁等生物碱。

咖啡因和可乐宁是一种兴奋中枢神经的药物。据测定,一瓶340克的可乐型饮料中含咖啡因50~80毫克,如果一次饮用含量达1克以上的咖啡因饮料,就会导致中枢神经系统兴奋,表现为躁动不安、呼吸加快、肌肉震颤、心动过速、期外收缩及失眠、眼花、耳鸣等。即使服用1克以下,由于对胃黏膜的刺激,也会出现恶心、呕吐、眩晕、心悸及心前区疼痛等中毒症状。胎儿对咖啡因尤为敏感,咖啡因能迅速通过胎盘而作用于胎儿,使胎儿受到不良影响。有人对孕鼠注射咖啡因实验证实,仔鼠易发生腭裂、脑膜膨出、脊柱裂、无下颌、无眼、骨骼异常、矮小、四肢畸形等现象。为了下一代的健康,孕妇应当慎饮或禁饮咖啡及可乐型饮料。

18、饮酒

研究表明,孕妇饮酒是造成婴儿畸形和智力迟钝的重要原因。

这是因为任何微量酒精都可以毫无阻挡地通过胎盘而进入胎儿体内,使得胎儿体内的酒精浓度和母体内酒精浓度一样。法国医学博士曾对127名有饮酒癖的妇女所生的孩子进行观察,发现他们都有共向的缺陷:单眼皮,即使双眼皮也不明显,鼻子扁平,内侧眼角眼皮外翻,脸蛋扁平且窄小,鼻沟模糊,上嘴唇薄且紧,下巴短。这种受酒精毒害、面部发育不健全的孩子约占饮酒母亲所生孩子的1/3。更为严重的是酒精对大脑和心脏的危害,孕妇饮酒导致婴儿患心脏病的约占30%。孕妇饮酒过多,生下的孩子不久就夭折的屡见不鲜.对死婴的解剖结果表明,其大脑不仅小于正常儿,而且脑发育不全或呈明显畸形状态。不少国家曾对胎儿期受酒精毒害的儿童进行智力测验,发现他们的智商都低于一般水平,大多数表现为反应迟钝、智力低下或者白痴。

Justice of Peace on campus

  1. The Univeristy of Melbourne Parkville Campus
    • Justice of Peace, available by appointment 12.30-2.30pm, Monday to Friday, at the Information Centre, ground floor, Union House.
    • (03) 8344 5415
  2. Monash University Caulfield Campus
    • Rod Simpson, Justice of the Peace, is available on Tuesdays from 10am to 2.30pm in A1.19 to provide a Certification and Statutory Declaration/Affidavit witnessing service. If you need documents witnessed at other times please contact Christel Kent who will provide you with names of other staff who can assist.


Just of Peace 可以免费certify文件,澳洲移民局是认可的。