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Russell Mickler, Principal Consultant, has over 17 years of professional experience leading and managing IT organizations.
Why Do Computers Get Slower?
Written on September 21, 2010
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Hey, it’s the 400th post on my blog! W00t w00t! Thanks for reading!
Now, this evening, I’ll be lecturing on this problem to a bunch of graduate students. And here’s just a snippit of what I’ll be talking to them about.
Computers get slower because of demands put on three resources: memory, processor, and I/O (input/output). The most common performance problem is caused by excessive paging.
Generally speaking, as a computer gets older and you load more software on it, and attach more devices to it, the more memory (RAM) is used. RAM is pretty desirable because it moves very fast, but we can’t run out of RAM or the system would just halt. Die. Stop. And operating systems have a safeguard against that.
When RAM starts becoming constrained, the PC starts writing to the hard disk to what’s called a page file. Now, the o/s will always page to the drive – that’s a normal part of how computers work, writing “pages” of memory to the hard disk – and when they do that, they’re writing to a hard drive which is comparatively very slow to RAM. It’s undesirable, but we don’t want the PC to just go caputz, right?
When computers start paging excessively and writing to the drive too often, that slows the whole system down. As I said, I/O to the hard drive is very slow as compared to RAM and meanwhile, the processor is waiting for commits to the drive, or, reads from the drive, just as if it were RAM. All of this interaction causes a downward spiral in performance.
To make matters worse, every year, new software is released that presumes you’ve got more RAM; even software you use on the Internet. That software takes more RAM footprint, causing more paging, causing more I/O activity to the hard disk, causing the processor to wait, slowing the whole thing down. So as time progresses, there is a natural diminishing of capability due to the evolutionary requirements of new software.
The fix for this is managing what’s in memory; admittedly, few users would understand how to do this on their own but the fewer things you see on the system tray or task bar, the better off you’ll be.
Also, a technician would investigate how paging is set up and how fast the drive is performing. This is where hard drive performance – how fast it’s spinning, and how quickly it can get to data – could effect paging and system response time.
It’s real simple: the less RAM there is available, the more the system must access the hard drive, and that access time slows the computer down.
Now, there’s no magic pill for this. No “registry cleaner”, ”performance optimization” software, or service pack is going to fix excessive paging; that stuff’s just a gimmick.
What it takes to fix it is a tech who understands these relationships between processor, memory, and I/O, and can measure the impact your software has on these resources. Beware the gimmick! Ask for it the next time you’re getting your PC serviced. You may be surprised about how much your tech does or doesn’t know about excessive paging.
R