We weten het allemaal, als Windows traag opstart of je gewoon een wat soepeler systeem wil hebben defragmenteer je je harde schijf even. De bestanden die door veelvuldig gebruik verspreid zijn geraakt over je harde schijf worden netjes bijelkaar geraapt en aanelkaar geplakt. International Data Corp. heeft een onderzoek gedaan naar fragmentatie, en dan vooral de kosten daarvan voor bedrijven. Het blijkt dat er miljarden guldens aan hard- en software upgrades bespaard zouden kunnen worden als de harde schijven van de PC's in bedrijven regelmatig gedefragmenteerd zouden worden. Bedrijven zouden niet goed op de hoogte zijn van het probleem:
Although the fragmentation problem isn't new, it lacks the "sex appeal" of computer viruses and other problems, Widen said. However, it can be equally deadly to the bottom-line and IT professionals' attempts to maintain efficient information systems. While popular viruses like the Love Bug or Melissa have captured the attention of IT managers, fragmentation remains a silent killer, quietly stalking systems, causing them to freeze up and slowing down applications by as much as 15 minutes. "Unless a red flag gets raised people don't get concerned about it or look at the problem," Widen said.[break]Uit testen in echte bedrijven bleek dat de performance winst van een regelmatige defrag sessie niet mis is; tot bijna 220% in Windows 2000 en ongeveer 55% in veel gebruikte programma's als Word en Excel. Totaal zou er daarom 50 miljard dollar per jaar uitgespaard kunnen worden:[/break]Network defragmentation clearly provides cost savings of several magnitudes when compared to manual defragmentation, Widen said. According to a cost comparison study by IDC, defragmenting 1,000 workstations and 10 servers manually would take 52,520 hours and cost $2.1 million, based on $40 per hour for IT staff time. Using a network-deployed defragmentation system, the job would require only 24 hours of staff time at a cost of $960.
IDC also compared the costs of hardware upgrades versus the cost of licensing and installing defragmentation software. It estimated the cost of purchasing 1,000 workstations, including staff set up time, at $3.2 million. In comparison, licensing Diskeeper NT for 10 servers and 1,000 workstations would cost only $24,000.
Looking at the figures you would assume that because the memory is faster then obviously the card is faster in situations where memory bandwidth is involved. Confusingly this is not necessarily the case. On a 128-bit architecture you take information from memory 128 bits at a time regardless of how much information you actually want. Suppose for example you only want 40 bits of information .. you still have to take 128-bits. So the
question is how many of the additional 88-bits are utilized? The answer varies hugely from one application to another but on average one is lucky to get 70% utilization. So for every 128-bits read from memory 26-bits are useless.
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