asnowfall: 2013

SSD basics

RAM and SSD

SSD is a NAND-type flash. RAM has infinite number of READ & WRITE capability. SSD(or Flash memory) can be overwritten something less than 100,000 times. (Depending on the type of flash memory, it may be as few as 1,000 times)

SSD Types

Single level cell (SLC): Stores 1 bit per internal cell, has a higher number of write cycles. Expensive.
Multi level cell (MLC): Stores multiple bits per internal cell. Cheap and consumes more power.

Sector, Block and Page in SSD

Sector/Page = 4,096 byte. // Unit of Read/Write

Block = 1024 * sector // Unit of Erasing

Chip = Thousands of Blocks

Read/Write unit and Erasable unit (Performance degrade and Aging)

Key thing is Unit of Erasing is larger than Unit of Read/Write. This affects the speed at which data is written to blank SSD and crowded SSD. Writing to blank SSD is fast because there is no need to make space, and writing to crowded SSD is slow because making space is an expensive operation.

Example, here we write a single sector on to a crowded SSD

1. Read the entire Block into the controller’s internal RAM. (because unit of Erasing is Block)

2. Erase the Block in the SSD.

3. Write new sector in to Block sitting in RAM.

4. Write the entire Block on to the SSD

As you see, writing one sector required working on extra 1023 sectors because unit of Erasing (one Block has 1024 sectors) is Block. So as SSD gets crowded, the rate of erasing increases resulting in not only bad performance but also aging because SSD has fixed number Write cycles.

Wear-leveling

This is implemented inside controller, to spread the wear (erases) across the SSD. This means SSD ages uniformly.

File Deletion and the Trim Command

Magnetic disk reads and writes nativley, in terms of sector, so the file deletion is a check-box inside a data structure. SSDs do not read and write sectors natively, and that lead to problems in earlier SSD. Then SSD controller's came with TRIM command.

Precautions

1. Fragmentation is not problem in SSD. If used, Disk defragmenter will wear our SSD faster.

2. NTFS was not designed with SSD in mind. NTFS issues lots of small writes to increase reliability and this is not good for SSD.

3. Using an SSD as your C: drive may drastically increase the speed of your system, but it will wear out before a magnetic disk would.

4. High-end magnetic disks can outperform low-end SSDs in some cases because many low-end SSDs perform poorly for small, random writes, which is a characteristic of the typical Windows workload

Source: Windows Internals (edition 6) by Mark E. Russinovich

SSD gets slower as they age

SSD becomes slower as they age. This is not my experience because I do not own SSD, but I have heard people complain. Windows Internals (edition 6) by Mark E. Russinovich explains why performance of SSD goes down.

Sector, Block and Page in SSD

Sector/Page = 4,096 byte. // (Unit of Read/Write)

Block = 1024 * sector // (Unit of Erasing)

Chip = Thousands of Blocks

Unit of Read/Write and Unit of Erasing

1. Read the entire Block into the controller’s internal RAM. (because unit of Erasing is Block)

2. Erase the Block in the SSD.

3. Write new sector in to Block sitting in RAM.

4. Write the entire Block on to the SSD

Source: Windows Internals (edition 6) by Mark E. Russinovich

WDM in under sea optical fiber cables

Under sea optical-fiber cables use WDM for data transfer. According to Wikipedia, this technology can accommodate past protocol without any need for hardware upgrade and cheap to implement.

http://en.wikipedia.org/wiki/Wavelength-division_multiplexing

Groundbreaker project by NSA

In 2001 NSA transferred large number of employees from their pay-roll to private contractors. Needless to say number of employee transferred in secret and contract was 2billion worth at the time of estimation. According to 'Shadow Factory' 35 contractors shared this contract.

Basically employees sat on the same chair but got paycheck from different company.

http://www.crocodyl.org/spies_for_hire/project_groundbreaker_nsa_contract

Unit 8200 of Israel Army and Spy softwares

It is easy to notice that antivirus, telecom spying software goes back to Israel company. Unit 8200 developed software for Mossad. Due to revolving-door practices executives from Unit 8200 started software companies based on their previous knowledge.In Israel military experience counts in job interview, especially if you are from Unit 8200.

Variant system, Narus, NICE, Comverse, Check point, ECtel are few examples.

Source: Shadow Factory by James Bamford

former NSA officers working for private contractors.

Revolving door is a pillar of corporations in US. This incestuous relation is strong in Defense. Here is few of NSA officers who quite NSA and headed to private firms. Once NSA guy joined the private firm, the profits of the company shoots. Following is may be a 1% of list. I do not think if it is possible to track this relation.

SPARTA - Maureen Baginski (NSA’s signals intelligence director) October 2006.
Applied Signal Technology -John P. Devine, (former NSA’s deputy director for technology)
TRW -William Studeman (former NSA director)
Cylink - McConnell’s (former NSA deputy director)
E Systems - Charles R. Lord(NSA deputy director)

William B. Black Jr, ex NSA guy was working for SAIC. He quit SAIC and joined NSA again in 2000. Later SAIC got $280 million Trailblazer contract, the project William B. Black Jr managed in NSA.

Source: Shadow Factory by James Bamford

Rocket fuel

Quote from the book Griftopia in the context of Greenspan denying the existence of bubble in market..

"humanity has reached a happy stage in history where bullshit can be used as rocket fuel"

ePub to PDF conversion using 'Adobe Acrobat Pro Extender"

Following the best method for converting ePub to PDF. I have used Calibre and font in the converted PDF is way to big, pages are too small. Following method gives normal font size. You need 'Adobe ACrobat Pro Extender"

1) Rename the extension from EPUB to RAR
2) Unzip
3) Open *.OPF file. Navigate to following TAG
           ""
4) Open 'Adobe ACrobat Pro Extender". Navigate to
   File -> Combine -> Merge Files in PDF
5) In "Combine files" dialog
     a. select 'single PDF' button on R-Top corner
    b. click on 'Add files'
    c. Add the all HTML files in a single shot
    d. Then re arrange the files in the ORDER given in "" of step-3
       Example:
           -> select XXXXX_cvi_YYY.html
              -> select XXXXX_tp_YYY.html
           -> select XXXXX_cop_YYY.html
6) Click Combine.

7) You have PDF

Science point of view?

Some say orange and orange-extract are same, at least in terms of nutrition(like both of them share citric acid etc..). People take pride while expressing this as if this is conquering of chemistry of Orange. In general this reductionist talk is seen as being scientifically aware.

Now there is an another group of people of who say Orange and orange-extract are not same because latter does not capture every aspect of Orange. Even this kind of talk is seen as sign of being scientifically aware.

How convincing these arguments are depends on listener.

Well I think orange-extract captures only one character of Orange. It is like defining Gandhi as Indian while ignoring all other characteristics.

Identify INLINE attachments in MAPI message

Inline attachments sit amidst the main body of e-mail. And the main body has syntax to refer to these attachments. This syntax is different for HTML and RTF. main bodies. HTML main body uses ContentID to refer to attachment. RTF main body uses /objattph to refer to attachment.

Exceptions
============
1) HTML mainbody some times uses RTF syntax to refer to inline attachment. Here is an example of that and note that there are no CID inside HTML stream. Correspondingly there is 'Content-ID' header for inline-attachment.

HTML mainbodypart
=================
img src="objattph://"

Attachment bodypart
====================
Content-Type: image/jpeg; name="Picture (Device Independent Bitmap) 1.jpg"
Content-Description: Picture (Device Independent Bitmap) 1.jpg
Content-Disposition: inline;
    filename="Picture (Device Independent Bitmap) 1.jpg";
    creation-date="Mon, 17 Jun 2013 18:21:33 GMT";
    modification-date="Mon, 17 Jun 2013 18:21:35 GMT"
Content-Transfer-Encoding: base64

Mushroom rice

Potato + Mushroom + Corn + spice + Garlic + small quantity of water.

Keep this on stove for 30+minutes with low flame.

Churn once is a while.

Finally mix with rice, then Eat.

Note: You may have to add salt because mushroom and corn are sweet

Humans taming energy

Simple burning fire(like forest fire) and steam engine are examples for non-structured and structured energies. Humans came to know about fire first but required 100s of years to channel that the energy to do sophisticated work in internal combustion engine, and the jet engine.

Extensive and Intensive physical properties

Extensive property depends on the 'extent' of the object. Value of Extensive property will be less for smaller object and more for larger object. Example: Weight is Extensive property. Weight of cup of water is smaller compared to weight of bucket full of water.

Intensive property is independent of the 'extent' of the object. Value of Intensive property will be same irrespective of the size of the object. Example: Density is Intensive property. Density is same for water that is inside cup or bucket.

IQWiG (Drug quality control in Germany)

http://en.wikipedia.org/wiki/Institute_for_Quality_and_Efficiency_in_Health_Care

In Germany drug makers have to prove to IQWiG that their products are good compared to the ones already available, then only Govt. buys from that drug maker. Not many western countries are courageous and honest enough do this. In US Medicare and Medicaid are paid by Govt., and Govt. does not even negotiate for cheap price. Drug maker does not have to prove anything about superiority to sell to Govt.

US is a dream customer for Pharma

EMA and FDA

EMA is the agency responsible for regulating medicines in EU. EMA is counterpart of FDA. Till recently EMA was not forth coming in sharing drug-trail data with independent researches like Cochrane. The reason given by EMA were:

- 'these documents have commercial data'
- 'these documents have patient personal data'
- 'these documents have data about the design of clinical trail'
- 'documents were shredded because it passed legal hold period'.
-'you can use the data for analysis but should not publish the results'

Going by these excuses EMA is representing drug makers, not the people or tax payers.

Independent researcher's struggle with EMA
http://www.cochrane.dk/research/EMA/

Now EMA has made all drug-trail data available for scrutiny.
http://www.reuters.com/article/2012/07/15/us-europe-medicines-idUSBRE86E04I20120715

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