tailieunhanh - A complete illustrated Guide to the PC Hardware phần 10

Với mới chết bộ nhớ cache L2 256 KB, kết hợp với bộ nhớ cache 128 KB L1 ban đầu, AMD thực sự có một sản phẩm rất mạnh mẽ. Thu hẹp bộ nhớ cache L2 CPU đường ống Những điều tuyệt vời về cuốn sách này là đơn giản của nó, bước từng bước tiếp cận. | An easy-read and illustrated Guide to SCSI IEE1394 FireWire and USB. meters. Traditional SCSI only works within 3 meters. LVD has to compete with FireWire which also has a powerful bandwidth. Adaptec have a SCSI-controller delivering up to 160 MB sec. This unitcalled Adaptec SCSI Card 3950U2 uses two independent Ultra2 SCSI buses in one card. It connects up to 30 SCSI devices What do you gain with SCSI top Expensive but good. SCSI makes the PC a more expensive but more versatile. The advantages are that on the same PC you have free access to use many and good units It is easy to add accessories as DAT streamers CD-ROM recorders MO drives scanners ZIP- and DVD-drives etc. You can use SCSI hard disks. You can use CDROM drives on SCSI which may give a better performance. The advantages of SCSI hard disks SCSI hard disk are generally of higher quality than other good SCSI disks come with a 5 year warranty. Traditionally they are faster than the EIDE disks. At 10 000 or 14 000 RPM they have shorter seek times. They also have a bigger cache. Another advantage is the large number of accessories which can be attached. If you buy a 18 GB SCSI disk today you will guaranteed need additional disk storage in a few years. Then you just add disk number two to the SCSI chain and later number three. The system is more flexible than EIDE where you can have a maximum of four units incl. CD-ROM. The SCSI hard disks can also adjust the sequence in the PC s disk read commands. This allows reading the tracks in an optimal sequence enabling minimal movements of the read write head. Quantum calls this technology ORCA Optimized Reordering Command Algorithm . It should improve performance by 20 . Finally the SCSI controller can multitask so the CPU is not locked up during hard disk operations which you can experience with IDE. SCSI hard disks can achieve substantially larger transfer capacity than the IDE drives but they have the same bottle necks the serial handling of bits