Again, you cannot look at *only* CPU utilization and make a judgment about the software, load, etc. Yes, it *could* be a problem, but the point I'm making is you don't know by looking *only* at CPU. It frequently is a symptom of something else happening -- the real bottleneck. For instance, it could be a symptom of running out of memory, but it shows up as CPU because there's a lot of paging going on.
To help understand this, imagine you walked into McDonald's. As soon as you put in your lunch order, the people behind the counter start running around like crazy. You get your order in 5 seconds. You go, "Wow, that was fast!" The next day you walk in and there's 30 people in line ahead of you. The people behind the counter are still working like crazy and each lunch still takes only 5 seconds, but you have to wait a lot longer. The workers are the CPU, the customers are the run queue. We haven't even started to talk about swapping, disk I/O, and other I/O. You might say, "Yeah, but if you could hire other workers that worked even faster, then each job might take only 2 seconds." That's true, but in our example it would cut down your wait time from 150 seconds to 60 seconds. That's a great improvement, but chances are the user (you) would still complain about it. Thanks for reading. This'll be the last time I'll post on this, this has all the markings of one of those threads Eric will have to close. You guys go one and have the last word. ----- Original Message ---- From: Jack Smith <jack.sm...@cliftonlaboratories.com> To: elecraft@mailman.qth.net Sent: Fri, February 19, 2010 1:46:47 PM Subject: Re: [Elecraft] W9OY on P3 The graphics processor makes a big difference. I have several Dell SX-260 computers that run SDR programs painfully slow, despite 2 GB of RAM and 2.5 GHz CPU. It turns out that Dell's graphic processor has no dedicated memory but rather shares normal RAM. That creates a huge bottleneck when running a graphics intensive program such as all the SDR software. Some is slightly worse than other but they all bog way down on the SX-260 compared with a machine with a separate graphics card and memory. Same SDR program on the SX-260 may run 70% CPU but only 10% on a computer with a separate graphics card and memory, with similar CPU speed and RAM. Jack K8ZOA On 2/19/2010 4:18 PM, ab2tc wrote: > I would have agreed if Windows had offered developers an easy way of > prioritizing threads and processes. But as far as I know it doesn't (or > developers don't know how to use it). In my experience the performance of a > PC with 90% CPU load is miserable for all processes running on it. With that > said, I don't see why PowerSDR should incur that kind of CPU load on a 3GHz > machine. I am running XP home edition on a dual core Dell at 2.9GHz and 2Gb > of RAM. My CPU utilization is hovering between 15 and 30% with all of the > following running: > > LP-Bridge > HRD > PowerSDR with EMU-0202 sound card at 192ks/s > VE7CC cluster client (highly recommended) > Iexplore composing this message > Thunderbird mail client > DX Atlas > > I can add more applications and the CPU barely nudges upwards. I think most > people would agree that a car that has to be driven always with the > accelerator nearly to the metal is underpowered and not much of a joy. I am > a firmware developer and we always worry whenever the CPU utilization > exceeds 50% even though we use OS's that allow intelligent prioritization of > tasks. > > AB2TC - Knut > > > Al Lorona wrote: > >> Just a minor point: There might be a misconception that high CPU >> utilization means your computer is inadequate for the task. >> >> Actually, you want the CPU to work hard for you. It isn't only CPU you >> should worry about, it's what is called the 'run queue'. The run queue >> determines how long your job has to wait until it's serviced by the >> computer. It's okay to have 100% CPU (and in fact you want it) if you >> don't have to wait at all. >> >> A person assessing the performance of a computer looks at several other >> things besides CPU when determining what to tune for better performance. >> >> >> Don Wilhelm-4 wrote: >> >>> >> >> >>> I am using a 3.0 GHz Pentium 4 with 1 GB of RAM, running >>> WinXP Pro and the CPU utilization ranges from 50% to 90%, so anyone >>> thinking of choosing this alternative with a lesser computer had better >>> think about a new computer first. >>> >> <snip> >> >> >> > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
