DIGIT-ARC read-only archive · snapshot: July 23, 2026

CPU usage increases to 100% when using TurboC

11 posts · originally from https://geek.digit.in/community/threads/cpu-usage-increases-to-100-when-using-turboc.91192/

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Shikhar Original post #1
Jun 23, 2008 at 3:08 PM
I have a P4 2.4 Ghz , 1024+256MB DDR RAM , 160+20GB HD. Win XP. Geforce FX 5500 256MB card.

I have Zonealarm security suite in the startup.
Whenever I run TurboC CPU usage increases from 2 - 3% to directly 100%. And as soon as I exit TurboC the CPU usage again drops to 2 - 3%. When using TurboC , PC is quite sluggish & sometimes input takes 1-2 seconds for display.

What should I do???

I never faced this problem when I used it on my P3 800MHz (about 4years back).

Thanks in advance.
yogeshm.007
Jun 23, 2008 at 6:34 PM
I've no clear idea about this.
Right click on the executable and go to properties, there you must see "Compatibility" tab, experiment with those settings...

I never faced this problem when I used it on my P3 800MHz (about 4years back).
You must have been running Win 98 then, and perhaps are running Win XP now.
QwertyManiac
Jun 23, 2008 at 6:39 PM
Its obviously because Turbo C and the programs its compiler generates, are both 16-bit. You are like in dinosaur age, complaining of animals being too huge for you to live with.
infra_red_dude
Jun 23, 2008 at 7:17 PM
I have a P4 2.4 Ghz , 1024+256MB DDR RAM , 160+20GB HD. Win XP. Geforce FX 5500 256MB card.

I have Zonealarm security suite in the startup.
Whenever I run TurboC CPU usage increases from 2 - 3% to directly 100%. And as soon as I exit TurboC the CPU usage again drops to 2 - 3%. When using TurboC , PC is quite sluggish & sometimes input takes 1-2 seconds for display.

What should I do???

I never faced this problem when I used it on my P3 800MHz (about 4years back).

Thanks in advance.
As Harsh said, its a 16bit app designed to be used in pure DOS. Under windows it runs on ntvdm. Its a known issue and afaik nothing can be done about it.
alok4best
Jun 23, 2008 at 8:07 PM
its perfectly fine, it used to take close to 100% on my PC too.

P.S->It doesn't mean that its not taking 100% anymore on my PC.
I have just stopped using Turbo C. :D
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Shikhar #6
Jun 23, 2008 at 8:21 PM
Thanks everyone for ur valuable replies. I am junking TurboC and thinking about using some new freeware C++ compiler.
dheeraj_kumar
Jun 23, 2008 at 9:55 PM
If so, I'll take the pleasure of recommending Microsoft Visual C++ 2008 Express Edition. :) Download the Platform SDK if needed :)
Krazy_About_Technology
Jun 24, 2008 at 3:31 AM
+1 to dheeraj_kumar. Turbo C runs using NT Virtual Device Manager executable that emulates the 16bit environment. Its normal for it to use 100% processor. But if you switch to full screen mode, by pressing Alt+Enter, the usage will decrease a bit. Its more when running a 16bit program in Windowed mode.
xbonez
xbonez #9
Jun 24, 2008 at 4:16 AM
in case you'd like to continue using Turbo C, as i did, all you need to do is launch it, then laucn task manager, and in the processes tab, give the process ntvdm below average priority...comp and compiler will both work fine after thatni
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Shikhar #10
Jun 27, 2008 at 10:16 PM
Thanks again. Great work guys!!!
krazzy
krazzy #11
Jun 27, 2008 at 10:36 PM
Same thing used to happen to me. And because of this my laptop battery which usually lasts a couple of hours on a full charge would go down in less than half an hour. And the whole thing would heat up. Thank God I don't need to use it now.