Excel ran out of resources while attempting to calculate one or more formulas - excel

Question

I have a workbook to do 'smart'-graphs on my expenses. It's been running for a year and there are now a lot of graphs and expenses. Excel now throws an out-of-resources error whenever I change anything or open the workbook. Thing is, I have lots of resources and its not using hardly any of them.
Win8 64bit w/ 8 core CPU and 32GB of ram
Office 2013 64bit
I have 2 sheets, the first sheet called Expenses has 3 columns [Date,Description,Amount] and about 1500 rows of data. The second sheet has a LOT (500 or so) of formulas that are all the same and aim to do "Sum all expenses between date X and Y where description matches -some needle-". The formula I have is this:
=
ABS(
SUMPRODUCT(
--(Expenses!A:A >= DATE(2011,12,1)),
--(Expenses!A:A < DATE(2012,1,1)),
--(ISNUMBER(FIND(C50,Expenses!B:B))),
Expenses!C:C
)
)
Can I give Excel more resources? (I'm happy for it to use all my ram, and chug my CPU for a few minutes).
Is there a more efficient way I can do this formula?
I understand that this formula is creating a large grid and masking my expenses list with it, and that for each formula this grid has to get created. Should I create a macro to do this more efficiently instead? If I had a macro, I would want to call it from a cell somehow like
=sumExpenses(<startDate>, <endDate>, <needle>)
Is that possible?
Thanks.

Answer 1

I had a similar problem where there were a few array formulas down about 150 rows and I got this error, which really baffled me because there really aren't that many formulas to calculate. I contacted our IT guy and he explained the following, some of which I understand, most of which I don't:
Generally when the computer tries to process large amounts of data, it uses multi-threaded calculation, where it uses all 8 processors that the computer tricks itself into thinking it has. When multi-threaded calculation is turned off, the computer doesn't throw the 'Excel ran out of resources...' error.
To turn off multi-threaded calculation, got to the 'File' tab in your Excel workbook and select 'Options'. On the right side of the box that appears select 'Advanced' and scroll down to the heading 'Formulas'. Under that heading is a check box that says 'Enable multi-threaded calculation'. Untick it, then select 'OK' and recalculate your formulas.

Answer 2

I had a go at creating a function that hopefully replicates what your current equation does in VBA with a few differences. Since I don't know the specifics of your second sheet the caching might not help at all.
If your second sheet uses the same date range for all calls to sumExpenses then it should be a bit quicker as it pre-sums everything on the first pass, If your date range changes throughout then its just doing a lot of work for nothing.
Public Cache As Object
Public CacheKey As String
Public Function sumExpenses(ByVal dS As Date, ByVal dE As Date, ByVal sN As String) As Variant
Dim Key As String
Key = Day(dS) & "-" & Month(dS) & "-" & Year(dS) & "_" & Day(dE) & "-" & Month(dE) & "-" & Year(dE)
If CacheKey = Key Then
If Not Cache Is Nothing Then
If Cache.Exists(sN) Then
sumExpenses = Cache(sN)
Exit Function
End If
Set Cache = Nothing
End If
End If
CacheKey = Key
Set Cache = CreateObject("Scripting.Dictionary")
Dim Expenses As Worksheet
Dim Row As Integer
Dim Item As String
Set Expenses = ThisWorkbook.Worksheets("Expenses")
Row = 1
While (Not Expenses.Cells(Row, 1) = "")
If Expenses.Cells(Row, 1).Value > dS And Expenses.Cells(Row, 1).Value < dE Then
Item = Expenses.Cells(Row, 2).Value
If Cache.Exists(Item) Then
Cache(Item) = Cache(Item) + Expenses.Cells(Row, 3).Value
Else
Cache.Add Item, Expenses.Cells(Row, 3).Value
End If
End If
Row = Row + 1
Wend
If Cache.Exists(sN) Then
sumExpenses = Cache(sN)
Else
sumExpenses = CVErr(xlErrNA)
End If
End Function
Public Sub resetCache()
Set Cache = Nothing
CacheKey = ""
End Sub

Answer 3

There could be many causes of this. I just wish Excel would tell us which one (or more) of the 'usual suspects' is committing the offence of RAM hogging at this time.
Also look for
Circular references
Fragmented Conditional formatting (caused by cutting, pasting, sorting, deleting and adding cells or rows.
Errors resulting in #N/A, #REF, #DIV/0! etc,
Over-use of the volatile functions TODAY(), NOW(), etc.
Too many different formats used
... in that order
While you're there, check for
Broken links. A formula relying on a fresh value from external data could return an error.
Any formulas containing #REF!. If your formulas are that messed these may well be present also. They will not cause an error flag but may cause some unreported errors. If your formulas are satisfied by an earlier condition the part of the formula containing #REF! will not be evaluated until other conditions prevail.

Answer 4

Fragmented conditional formatting was the case for me.
Older versions of the same workbook did not have an issue. Today, I cut/pasted many cells and the issue started occurring.
Removing the columns where I was cutting/pasting resolved the issue for me.
This is difficult to diagnose since conditional formatting does not immediately standout like normal formulas.