30. With Write-Through cache, each write operation to the cache is accompanied by a write operation to the main memory. That means, the data is written to the cache and the main memory at the same time.
With Write-Back cache, the CPU writes to the cache first. But the actual updating of main memory takes place at a later time.
31. EDO (Extended Data Out) memory is a type of RAM chip that will make improvements on the time to read from memory.
ECC (Error Checking and Correcting) memory means that data that is being read or transmitted will be checked for errors and, if necessary, corrected immediately.
With Registered memory, the memory chips contain registers that will re-drive the signal as it goes through the memory chip.
32. Processor package types:
- 8088, 8086 processors used 40 pin DIPs. 80286,80386, 80486, and some Pentium computers (60MHz, 66MHz) used PGA (Pin Grid Array).
- Pentium chips (75 MHz and above) used SPGA (Staggered PGA). Pentium II CPUs use catridge type mounting method, called "slot-1".
33. Hot swapping/ hot spare:
- A hot spare is a spare unit that is ready to take on the job of the main unit in the even of failure. Hot spare refers to the physical unit such as a disk drive or even a standby computer, such as in a clustered configuration. The failure may or may not be noticed by clients. For example, if the RAID system is configured with RAID 0, a failure may be noticed by the clients, whereas, if configured with RAID 5, the failure may not be noticed (in case of single point failure).
- Hot-Swapping is the ability to add and remove devices to a computer while the computer is running and have the operating system automatically recognize the change. Hot plugging is also called hot swapping.
- Universal Serial Bus (USB) and IEEE 1394 support hot plugging. This is also a feature of PCMCIA.
34. Unbuffered: Here the chipset controller communicates directly with the memory.
Buffered memory: A buffer isolates the memory from the controller chipset to minimize the load times that the chipset experiences. The load times can be bigger as the memory size increases.
35. Bus Mastering is a feature supported by some bus architectures that enables a controller connected to the bus to communicate directly with other devices on the bus without going through the CPU. Most modern bus architectures, including PCI, support bus mastering because it improves performance.
36. SDRAM is the standard used for mother boards that support 100MHz memory buses. Older DRAM technologies, such as EDO DRAM are designed for use with 66MHz memory bus.
37. While using Microsoft operating systems, only computers with Windows NT 4.0 or above can work as DHCP server. Any computer with Windows operating system can be a DHCP client.
38. The following tools are available for monitoring and optimization in Windows NT server in running in TCP/IP environment:
1. SNMP: SNMP can be used for monitoring and managing other nodes in a TCP/IP network. This include monitoring of WINS service, DHCP service, create performance counters related to TCP/IP etc.
2. Performance Monitor: This can be used to monitor several counters related to disk, memory, processor, cache etc.
3. Network Monitor: The Network Monitor monitors the data stream on the network and has access to the following information:
- The source and destination addresses of frames
- The header information
- The data being sent.
- You need to enter the criteria for monitoring before Network Monitor can start monitoring the data.
4. Event Viewer: Event Viewer displays information whether all the services / applications have started or running properly.
39. ISA, EISA, and PCI bus:
- The two types of PCI bridges are Host-PCI bridge, and PCI-PCI bridge.
- ISA cards can go into: 1. ISA slots, 2. EISA slots, and 3. VL Bus slots.
40. Memory chips:
- SRAM - Static random access memory - Uses transistors to store information
- DRAM - Dynamic random access memory - Need to be refreshed to retain data.
- ROM - Read only memory - Data in ROM can not be erased or changed
- PROM - Programmable ROM - Once programmed, data can't be erased or changed
- EPROM - Erasable PROM - Data can be erased by ultraviolet light and can be reprogrammed using a programmer.
- EEPROM - Electronically erasable PROM - Data can be erased electrically. Chip can then be reprogrammed. EEPROMs are frequently used to store BIOS.