Excel calculation monopolizes processor

[hmmm...]

I have a big workbook. Full calculation takes a couple of hours. That would be OK with me except that during the calculations Excel takes (according to the Task Manager) 99% of the processor's capacity, and the computer is useless for anything else. I cannot even stop the calculation with the Escape key--it just ignores me until it's done.

Isn't Windows supposed to multitask? I do have Excel's calculation option set to Manual, and when appropriate I do calculate one worksheet at a time. The machine has more memory (1 Gb) than Excel uses. So the problem seems to be the way Excel uses the processor. I tried setting Excel's "Priority" in the Task Mananger to "Low". But this didnt' help. Any ideas on how to work with this other than to buy a second computer and let Excel use one on its own?

 

[BrianB]

Probably not your problem, but worth mentioning.
You don't say which version of Windows you are using, but I have seen a problem with (I think) 95 or 98 that it can only handle up to 512mb. RAM after which it slows down.

I have Excel 97 and 200 running with no problems on my 2 gigahertz/512mb/XP machine and 2000 seems to run slower than 97.


Excel has its own internal memory manager. 97 handles up to 180mb. 2000 is more.

Sometimes Ctrl + Break keys will stop calculation. Try to avoid =VLOOKUP()(), this one's pig on big worksheets.

Hope this helps.

 

[hmmm...]

BrianB, thanks for the reply.

I am running Excel 2002 on a 2 GHz/1 Gb mem/Win2000 machine. I upgraded to Excel 2002 recently because it manages more memory than Excel 2000 does. 2002 does indeed work faster, but this problem of processor-hogging, anti-multitask, unstoppable calculation remains. I'll give Ctrl+Break keys a try to stop it.

Meanwhile, MS tech support says that next week they will give me a response about this issue and whether there's any way to deal with it. I'll pass it along to this thread if it seems useful.

 

[XL-Dennis]

Hi,

When running tasks that require lot of memory and lot of CPU-power then Windows is not capable of deliver true multitasking.

(Except for that one CPU can only handle one instruction per cycletime)

Unless You want to use 2 x CPU and at least with 1 GB RAM then I believe You have to accept the way it is.

BTW, I had the pleasure of running a "well-equipped" workstation last week with 2 x P4 2,53 Ghz and with 2 GB RAM. Starting Win XP Pro was impressive fast :wink:

Kind regards,
Dennis

 

[hmmm...]

Hi XL-Dennis,

So on a machine with 2 processors, can I limit Excel to using just one of the processors?

Thanks

 

[XL-Dennis]

Hi,

By having 2 CPUs Windows is capable of allocation process-time that is required for different task.

The allocation is (AFAIk) controled by windows.

But yes - You can do other stuff while large XL-files are processed :D

Personally I use two computer with one keyboard and mouse via a switcher and with two screens.

One that is used for handling long execution of large XL-files (60 - 90 MB) (the old computer) and the other one for all the other work (the new computer).

Kind regards,
Dennis

 

[hmmm...]

Dennis--Thanks again for the information. I hadn't seriously considered giving Excel its own computer, but now that you suggest it, it seems very practical--scrounging up an old machine is a lot easier than trying to obtain a dual processor.

--Arthur

 

[PaddyD]

FWIW:

http://www.decisionmodels.com/