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Topic: Debug window size (Read 2278 times) |
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rtr2
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Re: Debug window size
« Reply #10 on: Sep 12th, 2014, 11:11am » |
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on Sep 12th, 2014, 08:28am, DDRM wrote:| I was trying to keep the program as simple as possible for maximum clarity, since it was a minimal test of a specific problem, not a "working program" intended to run for more than a minute or two. |
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What you intended might not be what happens! I quite inadvertently left your program running over lunchtime, and when I got back to the office I realised immediately that things weren't right - the fan was screaming and there was a noticeable 'hot' smell (my old Pentium 4 - Netburst architecture - has a horrendous maximum dissipation of about 85 Watts!).
Hopefully no damage was done, and it wouldn't have been your fault if it had, but the addition of a WAIT 1 would have eliminated the risk. Do you really think its inclusion would have significantly compromised the 'simplicity' of your program? Wasn't there a possibility that an inexperienced user would build on your code without appreciating the issue?
Quote:| VDU26: Ooh, I almost never use that, so I didn't know about that! |
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VDU 26 resets the text and graphics viewports to correspond to the current window (client) dimensions - typically you might use it after maximising or resizing the window to allow you to make use of the increased area. You need to be aware that VDU 26 can, and typically will, alter the relative positioning of graphics (origin at the bottom-left) and ordinary 'VDU 4' text (origin at top-left).
Quote:| Mode 22 on a 1024x768 display: I wasn't - I have a 1280 x 1024 display |
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I must admit I automatically assumed the OP's display was 1024x768, both because all our desktop PCs (four of them) work at that resolution, and because it would have explained the symptom he described. It was also for a long time the most popular size, but it may no longer be.
But given his later clarification of the symptoms I may well have been wrong in that assumption.
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Malvern
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Re: Debug window size
« Reply #11 on: Sep 12th, 2014, 2:56pm » |
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on Sep 12th, 2014, 11:11am, g4bau wrote: the fan was screaming and there was a noticeable 'hot' smell (my old Pentium 4 - Netburst architecture - has a horrendous maximum dissipation of about 85 Watts!).
Hopefully no damage was done,
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Unlikely, but you could buy another one for £10 now.
Pentium 4's are designed to throttle back performance as the temperature rises above certain thresholds and safely shut down when the silicon gets too hot.
But best clean off your heatsink just the all the same.
If anyone wants more information about what really happens if you run at 100% CPU load then look up the Bitcoin mining sites.
People there run very high loads continuously trying to get rich so there is a lot of advice. Keep your fans running, your heatsink clean and monitor the on-board temperature sensors.
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Edja
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Posts: 60
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Re: Debug window size
« Reply #12 on: Sep 12th, 2014, 3:10pm » |
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Quote:| Keep your fans running, your heatsink clean and monitor the on-board temperature sensors |
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... or you could add a WAIT 1 to your code, as suggested.
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rtr2
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Re: Debug window size
« Reply #13 on: Sep 12th, 2014, 4:22pm » |
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on Sep 12th, 2014, 2:56pm, Malvern wrote:| People there run very high loads continuously trying to get rich so there is a lot of advice. Keep your fans running, your heatsink clean and monitor the on-board temperature sensors. |
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Certainly, if that's what you use your PC for, but nobody should need to do it simply to run a trivial 'BBC BASIC for Windows' program!
Another good place to find information is the 'overclocking' sites, where the consequences of running the CPU faster and hotter than intended are discussed. In particular you will find confirmation that the accelerated electromigration resulting from an elevated core temperature is a genuine phenomenon, which really can shorten the life of the chip.
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Malvern
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Re: Debug window size
« Reply #14 on: Sep 12th, 2014, 5:58pm » |
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Quote:| where the consequences of running the CPU faster and hotter than intended are discussed. |
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So overclocking gets mentioned now. The Microsoft analysis of fault histories that get sent to them suggests that Under-clocking is the best way to increase the life of the PC, and that laptops are more reliable than desktops and brand name PCs are more reliable than "white box." Now that is most likely because of heat related issues and how the manufacturers deal with it. Home brews and "White Box" are more likely to get it wrong.
Why do you keep on implying that running at 100% CPU load implies overheating? Heating, yes, but overheating is going to occur if the heat load is not being removed adequately. There are two parts to this equation and you focus on one.
As a physicist you know the heat flow equations. If the heat sinking capacity is large and the conduction interfaces are good then the chip temperature can easily be kept well below the design maximum silicon temperatures and should be to stop all the things you fear.
If the heat sinking is poor or non-existent or there is bad chip to heat sink conduction then you can overheat on very low loads, but you know that. But even that does not necessarily mean that your CPU will be destroyed. In the majority of cases it will generate and exception and shut down safely. You might get data loss but the CPU will survive. (Otherwise how would Microsoft get the data?)
The heat sink vendors will tell you just how bad the stock heat sinks are and how you are about to fry your PC. It's not true.
Back to BB4W trivial programs. Of course they should not use all the CPU capacity doing nothing useful. I never ever implied that was a good thing.
But your argument is akin to saying you shouldn't go on the Autobahn because your radiator might not be working properly.
And an overheating engine will shorten its life. And now we have added that if you over-rev it it can reduce the life of the engine. So only keep the car (or P4) for going to the shops?
Maybe it is because I majored in thermodynamics and designed heat exchangers for the first couple of years of my professional life that I hold such odd views.
If anyone has actual information about how long a CPU should last under any set of conditions that would be wonderful to see. It is information that does not seem to escape the foundries.
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rtr2
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Re: Debug window size
« Reply #15 on: Sep 12th, 2014, 9:31pm » |
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Quote:| Why do you keep on implying that running at 100% CPU load implies overheating? |
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You continue to miss the point. We are talking about unnecessarily running at 100% CPU, through the omission of a WAIT statement. That has a number of undesirable consequences:
It slows down other processes/threads running on the same core.
It depletes the battery when that is the source of power.
It uses extra energy and therefore adds to CO2 emissions.
It causes heating, which will shorten the life of the CPU chip. I have never said that 100% CPU load necessarily causes overheating, but simply that it may cause overheating. Neither you nor I know what proportion of PCs have insufficient or impaired cooling arrangements, such that running at 100% CPU for extended periods may cause damage (which I reiterate may not necessarily be catastrophic failure, but parametric changes caused by ion migration). But what is certain is that some do.
The remainder of your comments and insults are largely irrelevant and do not merit any response from me. I have no idea why you feel the need to be so obnoxious and provocative.
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| « Last Edit: Sep 12th, 2014, 9:48pm by rtr2 » |
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