Measuring and Improving Drive Performance
description
Transcript of Measuring and Improving Drive Performance
![Page 1: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/1.jpg)
Measuring and Improving Drive
Performance
section 5b
![Page 2: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/2.jpg)
This lesson includes the
following sections:
• Average Access Time
• File Compression
• Data-Transfer Rate
• Optimizing Disk Performance
• Drive-Interface Standards
![Page 3: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/3.jpg)
Average Access Time
• In storage devices, average access time (or seek time) is the time required for a read/write head to move to a spot on the storage medium.
• For storage devices, access time is measured in milliseconds (ms), or thousandths of a second. In memory, access time is measured in nanoseconds (ns), or one-billionths of a second.
• Diskette drives offer an average access time of 100 ms. Hard drives are faster, usually between 6 – 12 ms.
![Page 4: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/4.jpg)
Device Typical Access Time
Static RAM (SRAM) 5-15 ns
Dynamic RAM (DRAM) 50-70 ns
Read only memory (ROM) 55-250 ns
Hard disk drives 6-12 ms
CD ROM drives 80-800 ms
Tape drives 20-500 s
Typical Access Times for Memory and Storage Devices
![Page 5: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/5.jpg)
Disk Specifications by Seagate
![Page 6: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/6.jpg)
File Compression• File compression technology shrinks files so they take
up less disk space. • Using a compression utility, you can shrink multiple
files into a single archive file. •PKZIP, WinZip…
• Utilities such as Windows' DriveSpace enable you to compress the entire contents of your hard disk.
My archive
![Page 7: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/7.jpg)
WinZip File Compression Utility
![Page 8: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/8.jpg)
Data-Transfer Rate
• Data-transfer rate (or throughput) measures the time required for data to travel from one device to another.
• If a device transfers 45,000 bytes per second, its data-transfer rate is 45 KBps.
• Hard disks offer the fastest data-transfer rates of any storage device.
• MBps v.s. Mbps•Megabytes per second•Megabits per second
![Page 9: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/9.jpg)
![Page 10: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/10.jpg)
Optimizing Disk Performance
• Cleaning Up Unneeded Files•Temporary files.
•Used by Windows to store various versions of documents in progress•Usually stored them with file-name extension .tmp•You may use Windows built-in utility called Disk Cleanup to remove them
•Uninstalling
![Page 11: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/11.jpg)
Disk Cleanup Utility in Windows 2000
![Page 12: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/12.jpg)
Add/Remove Programs Utility in Windows 2000
![Page 13: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/13.jpg)
• Scanning a Disk for Errors
• Defragment a disk– Fragmentation occurs when a file is stored in
pieces on different sectors on the disk’s surface
Optimizing Disk Performance (Cont.)
![Page 14: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/14.jpg)
Hard Disk Fragmentation
One file can end up fragmented(scattered) over the disk surface.
![Page 15: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/15.jpg)
Hard Disk Fragmentation
This results in multiple head accesseswhich degrades performance.
![Page 16: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/16.jpg)
Disk Scanning Utility in Windows 2000
![Page 17: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/17.jpg)
Disk Defragmenter Utility in Windows 2000
![Page 18: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/18.jpg)
Drive-Interface Standards
• All PCs use a disk controller as an interface between a disk drive and the CPU. The two most common interface standards are EIDE and SCSI.
• EIDE (Enhanced Integrated Drive Electronics) has evolved over the years and has several variants, all of which have different names (Fast IDE, ATA, Fast ATA, ATA-2, ATA-3, ATA-4, and Ultra ATA).
• SCSI (Small Computer System Interface) is a faster, more flexible drive-interface standard found in high-performance computers.
![Page 19: Measuring and Improving Drive Performance](https://reader033.fdocuments.us/reader033/viewer/2022061319/5681429e550346895daed324/html5/thumbnails/19.jpg)
• Define average access time and explain how it is measured.
• Explain why file compression is a factor in drive performance.
• Define data transfer rate and describe how it is measured.
• Identify two drive interface standards.
Section 5b Review