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A Latvian and english Linux tiny operating system. used by golf & dvd lovers

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#1 2011-04-21 11:08:05

atang1
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Registered: 2006-03-30
Posts: 2705

USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Many linux people used USB drives. Smaller than 4 gB uses the old SLC(single layer semiconductor of one gate flash transistor). Many tiny Linux(150 mB) works well with 100,000 write cycle mtbf. But, Midi Linux had problems with large MLC(HC) flash cards(larger then 4 gB). Mandriva stopped selling USB installed cards, after complaints of card failures(10,000 cycles write mtbf).

MLC card were made up of multigate flash transistors and uses PRML compression scheme of hdd. Multigate has to write each gate more than once on the silicon dioxide gates to reflow the boric acid doping. So as compression ratio increases with number of gates per transistor, the life shortened by dividing with the number of gates. To lengthen the life of MLC cards, Linux has to take advantage of the 256 mB of nonvolitile sram to avoid writing to multigate transistors, which is not governed by gate failures. Use compressed data mostly read. Write only to sram.

This is now worked out on Asus EEEpc. Using two cards, one SLC(400x) to write, one MLC to store read only data. As usual, Asus paid attention to cpu stepping to avoid overheating, now USB data storage to replace hdd cheaply. Cards are cheaper than SSD.

XP sp3 is now divided into boot on the SLC card for execution of codes, and full install in the MLC card for read mostly and virtual memory to support the SLC.

If Asus had used nonvolitile sram, then they could have used only one HC card. But that means all data has to be reduced pixel transmission(no VGA).

On MLC mtbf, we are now studying boric acid percentage in Silicon dioxide gates to lengthen flash transistor life. The technology will be improved for write cycle life. Read cycle is infinite.

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2011-04-21 11:08:05

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#2 2011-04-21 13:54:14

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Speed of flash cards:
10x=1.5mbps
40x=6mbps; dma can be used to direct access the flash card used as hdd
133x=20 mbps
400x=60mbps; needs udma to speed up direct access of flash cards used as hdd
600x=80mbps

Speed of cdrom:
10x=1.5 mbps
24x=3.6 mbps
52x=7.8 mbps

speed of HDD:
ATA/33=33mbps Typical 33-45 mbps.
Sata 150=780 mbps max. Typically may run 20 mbps or 5 mbps dma speed.
Sata II=3000 mbps max. typically may run 20 mbps dma speed.
dma=5 mbps
udma=66 mbps

Speed of USB:
USB 1.1=12 mbps max.
USB 2.0=480 mbps max. Typical may run 1.5 mbps due to 10x cf cards speed.

Speed of WiFi/n:
WiFi/n=300 mbps max. Typically run 1-2 mbps(50-100 kBps in internet traffic) download of software.

1.5 mbps is easily enough to do movies on flash card. 60 mbps is almost as fast as HDD of today. In serial data transfer, done in packets, atm packet lossiness(resend) may seriously slow down data transfer. Wait state of atm must be synchronized to improve speed.

In packet switching, serial port speed is divided by the number of user packets, ao speed(TDMA) can deteriate very fast as users overload the speed of serial ports.

This leads to the technology of simultaneous data transfer through edgeQam channels where RF carrier frequency can carry IF frequency data channels(cdma) at the same time then separate them out by discriminators. Data(TDMA) transfer speed can improve tremendously.

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#3 2011-04-21 15:28:30

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Years ago, I learned that the speed of cpu depends on how fast the L2 caches is. At that time 500 mhz cpu ned L2 cache serial data transfer speed of 5 ghz. Just barely make the parallel processing speed of cpu.

Today most of the cpu speed are faster than L2 cache converting parallel speed to serial data speed. So cpu is always waiting for L2 cache data to appear.

When L2 cache is much faster than the parallel speed of cpu. Your computer will display results on the monitor much faster. This also means bus should be radio frequency antenna not laser diode and fiber optics, unless it is rF on glass.

So to design a fast cpu of 7.5 ghz, you need rF bus of 75 ghz serial data that connects all the circuits on the cpu. The USB drive also need 75 ghz bus by radio antenna.

If you are stuck with an old laptop; however, we can make the speed faster by improving data transfer speed, but not cpu processing speed? Or overcome memory limitatation of sockets, using ram boost software?

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#4 2011-04-22 09:54:29

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Here is the roadmap to a faster older laptop. Hardware first to be improved. Find a wifi/b pcmcia that works with your operating system. You might have to search ebay availability? This can do internet at least 1 or 2 mbps, even good enough to download live, movies.

Change hdd to cf card ata adaptor with 400x cf card. Try 4 gB SLC(not HC). This limits you to xP sp1 max. Add pcmcia card reader, so that you can add ramboost software to increase virtual memory to support small dram capacity. XP needs at least 128 mB. WinME can use only 32 mB, but too much update download from Microsoft that may not be available in the future. So, you are down to Win98se(two disk install). Or Win95c(one disk install). Using IE5.5sp2(earthlink disk or google download) and outlook express5 can do beyond Google search engines. Also do most social forums including hosting forums(your own free website on subdomain, crawled by search engines if submitted).

Many people like the open source Linux, that you can use older laptops. But you need at least a cdrw on your laptop. Puppy Linux can do multisession to save sessions on the cdr media. cdrom makes livecd of Linux a pleasure to use. If you can save each session of data, its almost good enough like hdd install. If you are lucky enough to have a dvd on your old laptop, you can entertain yourself with movies like portable DVD player. If you want to save money on DVDrw, you just use pcmcia card reader(32 gB HC) to read and write and play movies too.

If you do not have cdrom on your laptop; you can still search ebay to buy an cdrom connected to a pcmcia scsi controller. You might also be lucky enough to find 16 bit pcmcia adaptors, such as USB adaptor. USB 1.1 with 12 mbps is plenty fast for data transfer.

So far, Linux people used too much memory(512 mB), even SliTaz does not have swap filesystem(ramboost) that extends dram limitations. Puppy uses hdd for swap, but not card readers. Linux, if using 16 mB execution area, and use ramboost to swap OS and data, you can have a very old laptop(32 mB) and get on internet. Squashfs will further reduce the use of memory size.

Its there for you to fool around and have a nice toy, or use it every day as a tool.

There will be some interest I hope, for tiny Linux to work with ramboost software for older computers' clean install.

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#5 2011-04-23 13:45:42

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Why linux livecd is perfect for CF card hdd adaptor? Livecd is an operating system that is read only. Life of cf card will be infinite and exceed 15 years of life. You need a small USB flash card for swap file to extend dram size to 512 mB or 1 gB size for browsers with webpage history. An older non-HC card with 10x speeed would be good enough for 1.5 mbps data transfer.

With XP sp3, you need 6 GB storage, and you need to install to read only, store all data added in each session in any USB flash card. Autoupdate can be written to the cf card in the HDD adaptor.

Both linux and windows operating system will have previous session booted up to remind you of what was on the computer. If you are on the net only, you only need one previous session saved. History of many sessions can be rebuilt on present session with the latest information on any websites.

Read only is fast on slow flash cards. Avoiding write to slow flash cards will lengthen the life of all flash card to last 15 years.

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#6 2011-05-04 21:35:31

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Finally, the new cf card arrived from China, it is the ones used in GPS or cellphones 4 gB capacity. But it is MLC. On the hdd adaptor, I can install XP sp1, but can not boot from it.

So, the ones that can boot is SLC, which means it is limited to 2 or sometimes 4 gB capacity. Larger than 4 gB are all MLC. or nand rather than nor flash cards. MLC has 256 mB of sram in front of the data compression nand flash transistors. The 'process 2' operation can not boot an operating system, unless the operating system is transferred to ram first(vmlinux in drams). Then boot from ram as in Linux. Microsoft windows are different when you install the operating system on hdd.

So, with XP, you need sp1 on SLC flash card. then use MLC on the slave hdd adaptor for virtual memory. Because of the size of SLC, sp1 only can be used by itself, no sp2 or sp3 needed. Use Firefox v4 to replace IE6. SP1 can use wireless Bcm4318 wifi chip.

So, flash card operating system needs some planning before itt can be used to replace SSD.

Only tiny Linux operating system can use SLC flash card for LiveUSB setup. Mandriva being too large for nor flash cards, ran into flash card failures.

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#7 2011-05-05 09:10:05

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

So, the tip of howto use nand flash card to boot iso is to use lilo or grub, is obvious. When you try to scan nand device it will go into process 2 to access nand data compressed region of flash transistors for corrupted sectors.

This will make read only iso files very secure and mtbf very long time. Then the swap files will have at least 4 times larger than needed. ie., memory is 512 mB and swap file must be 2 gB on the nand for better mtbf.

This will solve many problems using nand flash cards to replace SSD. Nand read speed of 400x has 133x(20 mbps) as write speed.

Some of the hdd cf card adaptors of pin conversion scheme(pcmcia 68 pins, cf card 50 pins, hdd 44 pins), need to be sold with lilo or grub drivers for nand cards automatically. Or they can be made with progammable arrays to switch to process 2 for booting iso files.

Footnote:
Process 2 for nand device is the filesystem of data compression on the nand flash card. Process 1 is the non-volatile 256 mB of sram cache. Sram does need lilo or grub to boot process 2 read only iso file. However, from the cache to process 2 you must have the encoder and decoder for PRML data compression. In cellphones and gps devices, the cpu and rom has the bootloader to read and write to nand for booting iso file.

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#8 2011-05-06 11:12:59

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Finally, we come to the understanding of flash cards removable or fixed for hdd boot application. Fixed for hdd application(in dos, sys c: ) requires fixed location for bootmanager in mbr sector. Removable cards can use filesystem as partition, for linux, can use lilo or grub. Removable card can only be used for data hdd application.

Master and slave can both be fixed(sys c: ) for alternative boot system, using bios boot order.

There is a program to be downloaded from google search to fix the cf card for booting operating system. atcfwchq.com is a dos application program which fix the cf card to be bootable. You may have to use windows dos boot floppy to use this program. Or use the old SYS C: command? SYS c: may need more codes to do the data compression and sector by sector write on nand flash transistors.

Have fun. This old standard for booting hdd stopped us from using cf cards for booting as hdd. This also applies to sdhc hdd adaptors. Some one up there now understand why we still have floppy on laptops? Just to set flash cards to be system drives.

One more step is after sys c: or atcfwchq.com, you need to format to ntfs before you can install operating system. The old fat32 is formated wrong for boot sector address.

Do not be confused, when you install Linux livecd into USB drives. USB drives can be booted by bios order or boot floppy to redirect to USB drive. Iso bootable USB drives is fixed for bootmanager, different from removable USB data drives. Linux lilo and grub set the hdd to be bootable by partitions.

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#9 2011-05-06 11:47:19

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

When I installed XP on cf card, it did not boot because it was not sys c: processed. But the dma and udma speeds are ok to completely install the sp1. This cf card was used for the newest cellphones with the proper dma and udma speeds.

When I did sdhc XP install, the file loading stopped somewhere and can not load further. This maybe the speed of sdhc, because microsdhc goes further than sdhc. But still did not completey loaded all the files for sp1 install. For hdd substitute, sdhc may have to be 133x write; slower than 40x maybe unable to write all the sectors doing data compression as well as writing sector by sectors. Or maybe the data is written to the wrong fat address not sys'd.

So the saga goes on. But the details are now slowly being understood to use flash cards for hdd substitute to save battery life or extend the battery operation to 10 hours continous.

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#10 2011-05-08 11:51:23

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

It took Asus to work out their netbook hdd adaptor for cf cards(2). The first cf card is 2 gB(nonHC). Then they use a second HC cf card of higher capacity. Then they use a software to copy C to D drive. This made the two cf cards appear to be one continous drive to the cpu.

This makes nor flash cards do all the work(execution area), and the nand HC card did the copy and read only of many codes, as long as the dram requirement of operating system is sufficient with 2 gB. With flash transistors, the memory should be used mostly for read only.

However, on the internet, webpages are dynamic. To make flash cards work longer, webpages had to be reduced pixels in nature(mobile banking in text). and zoomed in video rams(dram). Nor flash card is for hybernation of data in execution area, to do instant on feature on rebooting.

Tablet LCD display has its own video rams for pixel scanning data storage.

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#11 2011-05-30 19:06:14

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

All these discussions, just so that we can use cheap 4 gB SD(SLC nor) card and cheap ide adaptors to run old laptops on XP sp1 and Firefox4 that people had stripped out the big hdd. Of course, SDHC(MLC nand) will become cheap still.

It is really an exercise to design the next generation of mainframe computers where hundreds of 8 bit cpus will run USB bus with nand flash memory. Battery usage will be minimal.

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#12 2011-07-24 16:40:02

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

It does not take long for computer architecture to change yet again. Since nand flash cards uses 256 mb of non volatile sram. Srams are fast, and can be used as dynamic memory; if only you can fit tiny operating system into 96 mB(16 mB execution area, 64 mB of operating system and 16 mB of swap cache). This architecture does not use disk operating system, but only use memory bank switching s operting system.

The rest of the 256 mB of free memory can be used for virtual memory for internet data transfer. On the nand data compression free memory area, we need operating system runtime codes also. This idea is to be able to bank switch the compressed data storage area also run the computer applications.

This kind of architecture as compared to IBMPC is favourable. Because IBMPC only uses 456 kB for execution area. then use extended or expanded memory with FAT table to store files like in a disk operating system, but in dynamic memory.

So, the tablets and netbooks with ARM cpu do not run disk operating system, but run memory bank switching system on many flash memory cards. Each memory card will have its own operating sysem embedded(16 mB execution area plus 8 mB of cache swap area.

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#13 2011-08-01 09:10:35

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

This change of hardware architecture to USB memory cards or MicroSD flash card from hdd is significant because most operating system will be changed from disk operating system to memory bank switching operating system.

Memory banks of database in internet servers can be switched by packets(posix); using search engines.

The operating system game is pretty much over. as more and more tablets and netbooks will be using browser as operating system.

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#14 2011-09-16 10:36:56

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

Every once in a while, flash cards are removed without shutting down the power. And flash memory were lost. 'My computer' will not recognize it.

You need to download the panasonic sd formatter 2008 for a quick fix. Google then download 2.0.

Once installed, it will do a quick format and/or resize it. then windows explorer will recognize it and you can save programs on it again, Best by drag and drop from the cdrom or hdd to the flash card any program you desire in window explorer. You can fill up the flash card in a hurry..

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#15 2012-04-06 11:17:20

atang1
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Registered: 2006-03-30
Posts: 2705

Re: USB drives using SLC/MLC for longer MTBF? upgrade laptops? quick fix

latest ARM A10 has solution using nand flash cards to do boot. Nand flash cards are structure differently. 256 mB of nonvolitile sdram for cache purpose and the rest(nand) to store data compressed. Old nand was two gates on each transistor. New nand may have 3-8 gates per transistor for data compression table.

ARM A10 leaves boot loader in the data cache part to boot the operating system then store all the rest of the operating system in the data compressed area.

So, we now know, old ARM cpu can only do non SDHC(nor) card upto 2 gB. A10 can go upto 32 gB of nand flash cards for operating system.

nor is SLC. nand is MLC.

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