PENDUKUNG PERANGKAT LUNAK SISTEM
Standar Kompetensi Kerja Nasional Indonesia Sektor Teknologi Informasi dan Komunikasi Sub Sektor Jaringan Komputer dan Sistem AdministrasiMendukung Perangkat Lunak Sistem112KODE UNIT : TIK.JK02.025.01JUDUL UNIT : Mendukung Perangkat Lunak SistemDESKRIPSI UNIT : Unit ini menjelaskan kemampuan yang diperlukanuntuk mengoperasikan dan mendukung perangkatlunak sistem.ELEMEN KOMPETENSIKRITERIA UNJUK KERJA01 Merawat perangkatlunak sistem1.1 Efektifitas sistem dievaluasi terhadappersyaratan vendor dan persyaratan unjuk kerjaorganisasi untuk menentukan aktivitasperawatan yang harus dilakukan.1.2 Utilitas sistem, struktur file (berkas) dan disk(cakram), serta berkas-berkas dan laporan unjukkerja digunakan untuk mengidentifikasi adanyaperiode puncak dan permasalahan unjuk kerjayang mungkin terjadi.1.3 Level data sistem dimonitor untuk menentukanapakah untuk kerja sistem konsisten terhadapstandar yang telah ditentukan.1.4 Identifikasi masalah dilakukan menggunakan toolsistem yang tepat.1.5 Sistem dimonitor dan disetel ulang bila perluuntuk memperbaiki unjuk kerja.02 Memasang perangkatlunak dan mengelolaberkas sistem2.1 Persyaratan sistem pengguna dievaluasi danstruktur berkas dan folder yang sesuai dimonitor.2.2 Tools administrasi dan sistem yang sesuaidigunakan untuk membuat struktur berkas danfolder.2.3 Keamanan, akses dan berbagi pakai berkassistem untuk memenuhi kebutuhan klienditetapkan.2.4 Kebutuhan proteksi virus jaringan diidentifikasisesuai prosedur organisasi.2.5 Berkas sistem diuji untuk menjamin akses yangtepat tersedia untuk kelompok pengguna.2.6 Konstruksi program sederhana diperiksa untukdicocokkan dengan pedoman organisasi.Standar Kompetensi Kerja Nasional Indonesia Sektor Teknologi Informasi dan Komunikasi Sub Sektor Jaringan Komputer dan Sistem AdministrasiMendukung Perangkat Lunak Sistem113ELEMEN KOMPETENSIKRITERIA UNJUK KERJA2.7 Berkas sistem yang dibuat berdasarkan standarorganisasi didokumentasikan.03 Mengelola pemakaiansistem3.1 Akses kepada sistem diberikan kepadapengguna.3.2 Akses dan penggunaan sistem untuk penggunadibuat tanpa kesalahan.3.3 Akses pada informasi dan sumber daya dibuatjelas dan nyata.3.4 Layanan sistem diintegrasikan dengan bantuantool sistem.04 Memonitor keamanansistem.4.1 Akses pengguna dimonitor sesuai dengan levelakses pengguna.4.2 Persyaratan keamanan untuk pengguna dandata yang tersimpan pada jaringan ditinjauulang.4.3 Resiko terhadap penyebaran data, prosespemulihan, dan pencegahannya ditentukan.4.4 Sistem yang menyediakan layanan back up danrestore dari gangguan kerusakan diterapkan.4.5 Prosedur pemulihan bencana didokumentasikan.05 Menjalankan back upsistem5.1 Sistem dipindai dari adanya virus dan virus yangterdeteksi dihapus.5.2 Back up sistem dilaksanakan berdasarkankebutuhan sistem dan organisasi.5.3 Back up sistem dilaksanakan secara teratur danberkala.5.4 Back up sistem dicatat sesuai persyaratanorganisasi.06 Memulihkan (restore)sistem dari back up.6.1 Pemulihan sistem dilaksanakan sesuai pedomanorganisasi.6.2 Sistem yang dipulihkan dioptimalisasiberdasarkan persyaratan organisasi.6.3 Sistem yang dipulihkan didokumentasikansesuai dengan persyaratan organisasi.Standar Kompetensi Kerja Nasional Indonesia Sektor Teknologi Informasi dan Komunikasi Sub Sektor Jaringan Komputer dan Sistem AdministrasiMendukung Perangkat Lunak Sistem114BATASAN VARIABEL1. Unit ini berlaku untuk seluruh sektor teknologi informasi dan komunikasi.2. Dalam melaksanakan unit kompetensi ini didukung dengan tersedianya:2.1 Sistem operasi, sistem komputer, dan sistem jaringan komputer.2.2 Basia data / DBMS.2.3 Standar dan prosedur organisasi.2.4 Perangkat keras, perangkat lunak dan file sistem.PANDUAN PENILAIAN1. Pengetahuan dan keterampilan penunjangUntuk mendemontrasikan kompetensi, memerlukan bukti keterampilan danpengetahuan di bidang berikut ini :1.1 Pengetahuan dasar1.1.1 Pengetahuan mengenai produk produk vendor.1.1.2 Pengetahuan mengenai bisnis organisasi / perusahaan.1.1.3 Pengetahuan mengenai Quality Assurance.1.1.4 Pengetahuan mengenai sistem manajemen perubahan.1.2 Keterampilan dasar1.2.1 Keahlian menganalisis proses kerja yag rutin dan non rutin.1.2.2 Keahlian merencanakan proyek.1.2.3 Keahlian bekerja sama dengan tim.1.2.4 Keahlian menulis / membuat laporan.2. Konteks penilaianKompetensi harus diujikan di tempat kerja atau di tempat lain secara praktekdengan kondisi kerja sesuai dengan keadaan normal.3. Aspek penting penilaianAspek yang harus diperhatikan :3.1 Kemampuan untuk memelihara sistem perangkat lunak.3.2 Kemampuan untuk mengatur sistem file.3.3 Kemampuan untuk Mengatur pengguna sistem.3.4 Kemampuan untuk melakukan back up sistem.3.5 Kemampuan untuk melakukan restore sistem.4. Kaitan dengan unit-unit lainnya4.1 Unit ini didukung oleh pengetahuan dan keterampilan dalam unitkompetensi yang berkaitan dengan:4.1.1 Berkomunikasi dengan klien.4.1.2 Memasang dan mengkonfigurasi perangkat keras pada sistemjaringan.4.1.3 Memasang dan mengkonfigurasi perangkat lunak pada sistemjaringan.4.1.4 Memasang dan mengkonfigurasi sistem jaringan.4.1.5 Melakukan back up dan restore sistem.4.2 Pengembangan pelatihan untuk memenuhi persyaratan dalam unit iniperlu dilakukan dengan hati-hati. Untuk pelatihan pra-kejuruan umum,Standar Kompetensi Kerja Nasional Indonesia Sektor Teknologi Informasi dan Komunikasi Sub Sektor Jaringan Komputer dan Sistem AdministrasiMendukung Perangkat Lunak Sistem115institusi harus menyediakan pelatihan yang mempertimbangkanserangkaian konteks industri seutuhnya tanpa bias terhadap sektortertentu. Batasan variabel akan membantu dalam hal ini. Untuk sektortertentu / khusus, pelatihan harus disesuaikan agar dapat memenuhikebutuhan sektor tersebut.Kompetensi KunciNO KOMPETENSI KUNCI DALAM UNIT INI TINGKAT1 Mengumpulkan, mengorganisir dan menganalisa informasi 32 Mengkomunikasikan ide-ide dan informasi 23 Merencanakan dan mengorganisir aktivitas-aktivitas 24 Bekerja dengan orang lain dan kelompok 25 Menggunakan ide-ide dan teknik matematika 26 Memecahkan masalah 27 Menggunakan teknologi 3
Random access memory
From Wikipedia, the free encyclopedia
Random access memory (usually known by its acronym, RAM) is a type of computer data storage. It today takes the form of integrated circuits that allow the stored data to be accessed in any order, i.e. at random. The word random thus refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.[1]
This contrasts with storage mechanisms such as tapes, magnetic discs and optical discs, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item.
The word RAM is mostly associated with volatile types of memory, where the information is lost when power is switched off. However, many other types of memory are RAM as well (i.e. Random Access Memory), including most types of ROM and a kind of flash memory called NOR-Flash.
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[edit] History
The first type of random access memory was the magnetic core memory, developed in 1951, and used in all computers up until the development of the static and dynamic RAM integrated circuits in the late 1960s and early 1970s. Prior to the development of the magnetic core memory computers used relays or vacuum tubes to perform memory functions.
[edit] Overview
[edit] Types of RAM
Modern types of writable RAM generally store a bit of data in either the state of a flip-flop, as in SRAM (static RAM), or as a charge in a capacitor (or transistor gate), as in DRAM (dynamic RAM), EPROM, EEPROM and Flash. Some types have circuitry to detect and/or correct random faults called memory errors in the stored data, using parity bits or error correction codes. RAM of the read-only type, ROM, instead uses a metal mask to permanently enable/disable selected transistors, instead of storing a charge in them.
As both SRAM and DRAM are volatile, other forms of computer storage, such as disks and magnetic tapes, have been used as "permanent" storage in traditional computers. Many newer products such as PDAs and small music players (up to 160 GB in Jan 2008) do not have hard disks, but often rely on flash memory to maintain data between sessions of use; the same can be said about products such as mobile phones, advanced calculators, synthesizers etc; even certain categories of personal computers, such as the OLPC XO-1, have begun replacing magnetic disk with so called flash drives. There are two basic types of flash memory: the NOR type, which is capable of true random access, and the NAND type, which is not; the former is therefore often used in place of ROM, while the latter is used in most memory cards and solid-state drives, due to a lower price.
[edit] Memory hierarchy
Many computer systems have a memory hierarchy consisting of CPU registers, on-die SRAM caches, external caches, DRAM, paging systems, and virtual memory or swap space on a hard drive. This entire pool of memory may be referred to as "RAM" by many developers, even though the various subsystems can have very different access times, violating the original concept behind the random access term in RAM. Even within a hierarchy level such as DRAM, the specific row, column, bank, rank, channel, or interleave organization of the components make the access time variable, although not to the extent that rotating storage media or a tape is variable. (Generally, the memory hierarchy follows the access time with the fast CPU registers at the top and the slow hard drive at the bottom.)
In most modern personal computers, the RAM comes in easily upgraded form of modules called memory modules or DRAM modules about the size of a few sticks of chewing gum. These can quickly be replaced should they become damaged or too small for current purposes. As suggested above, smaller amounts of RAM (mostly SRAM) are also integrated in the CPU and other ICs on the motherboard, as well as in hard-drives, CD-ROMs, and several other parts of the computer system.
[edit] Swapping
If a computer becomes low on RAM during intensive application cycles, the computer can resort to swapping. In this case, the computer temporarily uses hard drive space as additional memory. Constantly relying on this type of backup memory is called thrashing, which is generally undesirable because it lowers overall system performance. In order to reduce the dependency on swapping, more RAM can be installed.
[edit] Other uses of the term
Other physical devices with read/write capability can have "RAM" in their names: for example, DVD-RAM. "Random access" is also the name of an indexing method: hence, disk storage is often called "random access" because the reading head can move relatively quickly from one piece of data to another, and does not have to read all the data in between. However the final "M" is crucial: "RAM" (provided there is no additional term as in "DVD-RAM") always refers to a solid-state device.
[edit] "RAM disks"
Software can "partition" a portion of a computer's RAM, allowing it to act as a much faster hard drive that is called a RAM disk. Unless the memory used is non-volatile, a RAM disk loses the stored data when the computer is shut down. However, volatile memory can retain its data when the computer is shut down if it has a separate power source, usually a battery.
[edit] Recent developments
Several new types of non-volatile RAM, which will preserve data while powered down, are under development. The technologies used include carbon nanotubes and the magnetic tunnel effect. In summer 2003, a 128 KB magnetic RAM chip manufactured with 0.18 µm technology was introduced. The core technology of MRAM is based on the magnetic tunnel effect. In June 2004, Infineon Technologies unveiled a 16 MB prototype again based on 0.18 µm technology. Nantero built a functioning carbon nanotube memory prototype 10 GB array in 2004. Whether some of these technologies will be able to eventually take a significant market share from either DRAM, SRAM, or flash-memory technology, remains to be seen however.
In 2006, "Solid-state drives" (based on flash memory) with capacities exceeding 150 gigabytes and speeds far exceeding traditional disks have become available. This development has started to blur the definition between traditional random access memory and "disks", dramatically reducing the difference in performance
[edit] Memory wall
The "memory wall" is the growing disparity of speed between CPU and memory outside the CPU chip. An important reason for this disparity is the limited communication bandwidth beyond chip boundaries. From 1986 to 2000, CPU speed improved at an annual rate of 55% while memory speed only improved at 10%. Given these trends, it was expected that memory latency would become an overwhelming bottleneck in computer performance. [2]
Currently, CPU speed improvements have slowed significantly partly due to major physical barriers and partly because current CPU designs have already hit the memory wall in some sense. Intel summarized these causes in their Platform 2015 documentation (PDF):
“First of all, as chip geometries shrink and clock frequencies rise, the transistor leakage current increases, leading to excess power consumption and heat (more on power consumption below). Secondly, the advantages of higher clock speeds are in part negated by memory latency, since memory access times have not been able to keep pace with increasing clock frequencies. Third, for certain applications, traditional serial architectures are becoming less efficient as processors get faster (due to the so-called Von Neumann bottleneck), further undercutting any gains that frequency increases might otherwise buy. In addition, partly due to limitations in the means of producing inductance within solid state devices, resistance-capacitance (RC) delays in signal transmission are growing as feature sizes shrink, imposing an additional bottleneck that frequency increases don't address.”
The RC delays in signal transmission were also noted in Clock Rate versus IPC: The End of the Road for Conventional Microarchitectures which projects a maximum of 12.5% average annual CPU performance improvement between 2000 and 2014. The data on Intel Processors clearly shows a slowdown in performance improvements in recent processors. However, Intel's new processors, Core 2 Duo (codenamed Conroe) show a significant improvement over previous Pentium 4 processors; due to a more efficient architecture, performance increased while clock rate actually decreased.
[edit] See also
- CAS latency (CL)
- DIMM
- DVD-RAM
- Dual-channel architecture
- Error-correcting code (ECC)
- Registered/Buffered memory
- Compact Flash
- PC card
- Memory shaving
- Static RAM (SRAM)
- STT RAM (Spin Torque Transfer RAM)
- Non-Volatile RAM (NVRAM)
- Dynamic RAM (DRAM)
- Fast Page Mode DRAM
- EDO RAM or Extended Data Out DRAM
- XDR DRAM
- SDRAM or Synchronous DRAM
- DDR SDRAM or Double Data Rate Synchronous DRAM; now being replaced by DDR2 SDRAM
- RDRAM or Rambus DRAM
[edit] Terminology
[edit] Notes and references
- ^ Strictly speaking, modern types of DRAM are therefore not truly (or technically) random access, as data are read in burst; the name DRAM has stuck however.
- ^ The term was coined in Hitting the Memory Wall: Implications of the Obvious (PDF).
[edit] External links
- How RAM Works – Article by Jeff Tyson and Dave Coustan
