CPU and RAM usage

[Maxheadroom]

is there a reason why when i run a programe like antivirus scan or adaware my cpu dosent use all of its capabilities to speed up the scanning process?
for instance with firefox, adaware scanning and what ever progs are in the back ground running my cpu usage is still at a steady 5%, why isnt that upto say 70% so the scan will be done a lot quicker?
thanks

 

[ignatzatsonic]

Some scanning programs have a specific menu choice or slider where that can be controlled. I haven't used Adaware in a long time and can't recall about it. Have you checked all the configuration choices for the programs in question?

I suspect some of the problem may be due to the way the program is written and Windows internal choices as to what is most important.

 

[Roddy]

And I beleive WIN7 has much lower memory and CPU usage requirements versus Vista especially. Most anecdotal evidence suggests this. Also, whilst admitting I am not comparing apples with apples, when I boot into Vista I notice my CPU usually runs at about 40% and my memory at around 25-30% (fluctuates a bit). When I boot into WIN7 those numbers drop to about 25% and 15% respectivley.

Opening and using the same apps (Word, IE8 and Outlook) there are noticeable jumps in Vista CPU and memory usage. The jumps in WIN7, whilst still there, are nowhere near as pronounced,

I saw a graph in a Essential Guide to Windows7 magazine I picked up yesterday which highlighted the differences in Vista v WIN7 memory usage. Internal Microsoft graph, mind you, but these likewise backed up other PC magazines findings and my own observations...WIN7 is simply far better at managing these requirements.

Rgds
Rod

 

[H2SO4]

A very good question

In addition to what others have said already, consider the possibility that the scanning procedure may not be processor or memory-bound. In other words, the bottleneck is not the processor or the amount of memory, but other factors - the disk subsystem being the most obvious.

Scanning a bunch of files for "known bad" (malware) contents involves a repetitive sequence of events:

a) decide which file to scan
b) read the file into memory
c) scan the in-memory content
d) record results
Then loop back up to (a) until done.

Those actions vary in their use of specific hardware resources. Some, such as (c), are primarily dependent on the processor and memory. The speed with which files and file fragments can be read into memory is, however, more limited by the disk horsepower.

Memory utilisation doesn't necessarily have to go very high because the same memory is reused as one file fragment is scanned, and the operation moves on to the next one.

Combine all that, and you end up with a processor that's mostly waiting for the disk subsystem to furnish the next file fragment to scan, and memory which is just being purged and reused over and over again.

Result: processor utilisation substantially lower than 100%. Memory footprint unremarkable and stable in size.

 

[Maxheadroom]

ahh ok so if i understand what youve said there's a bottle neck occurring where the CPU can deal with alot more than the HDD can give in a few operations, so to see an increase in CPU usage running those same apps i would need a faster HDD?

 

[H2SO4]

ahh ok so if i understand what youve said there's a bottle neck occurring where the CPU can deal with alot more than the HDD can give in a few operations, so to see an increase in CPU usage running those same apps i would need a faster HDD?

Yes, exactly. The CPU is so fast that it only takes a small percentage of its total capabilities to process the data at the maximum speed that the other components - including the HDD - are capable of managing.

Disregarding for a minute the effect of any type of artificial self-throttling by the scanning app, which is what ignatzatsonic pointed out (and a good point too!), the combination of a faster disk and faster memory would in theory provide work for the CPU at a greater rate, leading to higher CPU utilisation.

If the CPU was "pegged" at 100% while it was doing the processing, then you could safely conclude that the CPU itself is the bottleneck, and that other system components are waiting on it to finish.

There's always a bottleneck, in every system.

 

[Maxheadroom]

i was thinking of overclocking my cpu when i got it but now looking at the usage and the fact that it hardly goes over 25% would i be wasting my time?

 

[H2SO4]

i was thinking of overclocking my cpu when i got it but now looking at the usage and the fact that it hardly goes over 25% would i be wasting my time?

I'm strongly biased against overclocking because it makes the hardware potentially unreliable, and that gives me nightmares.

Having said that, a faster processor will not go to waste just because an AV scanning operation may be disk-bound rather than processor-bound. In many other types of usage scenarios, the limiting factor will be the processor.

More grunt is always a good thing.