Why is excel only using one cpu?

Question

I’m using excel to crunch massive amounts of data. I was previously using my 8th gen I7 laptop but this wasn’t able to run the spreadsheet any more, despite making lots of efficiencies with formula and macros.

I have now purchase a new desktop Whitchurch has 18cores and 128gb of ram. Whilst the application crashes less, it still seems to broadly go at the same speed, or perhaps a little faster.

I’m using a 64bit version of excel on a 64bit version of windows OS. I have set the priority of the app in task manager to high (and also tried real-time). I have changed the options within excel to use all of the available cores - 18 physical, 36 in total. Excel states that there are 36 threads calculating when I executed the macros which seems to make sense.

When using the resource monitor in windows I can see that whilst all of the CPU’s are performing some excel tasks (all each below 2%) only one cpu seems to be dealing with excel - and it’s running at 100% pretty much all the time. If I set affinity to remove that cpu from the allocated resources for excel, it simply dumps all of that activity onto another individual cpu.

This is not at all what I was expecting, it should spread the threads across all of the CPU’s.

Help!

Answer 1

Go to your pc's BIOS and check the settings for multi threading check to see if it is set to the correct threading setting:

How to enable hyper-threading in Windows 10 and is it needed? - Auslogics blog

Answer 2

Hi Stefan.Combes, hope you're doing well. I’m Ian, and I’m happy to help you today.

I'm sorry to hear about this issue.

This issue is more of a tech issue.

You can post it in here.

https://social.technet.microsoft.com/Forums/en-...

To share some ideas of mine.

You can enable the multi-threaded calculation by following the steps below.

1. Go to File > Options > Advanced
2. Under Formula section, make sure to turn on the "Enable multi-threaded calculation.

3, Set your desire Number of calculation thread.

4. Click Ok.

Also one thing I'm sure about is Excel VBA (Macro) only use one thread.

If you want to implement multithreading, then you need to implement it via code.

For the Excel itself, you can check the articles below.

https://docs.microsoft.com/en-us/office/client-...

https://answers.microsoft.com/en-us/msoffice/fo...

This is a user-to-user support forum and I am a fellow user.

I hope this helps, but please let me know if you need anything else.