Excel 2010 Spreadsheet Constantly "Not Responding"

We have a spreadsheet that is currently 190MB in our environment that is extremely sluggish when opened.

When filters are turned on, everything slows to a crawl. Inserting a column with filters on will cause Excel to hang indefinitely until the process is killed in Task Manager.

When attempting to turn off the filter, I am usually presented with a "Excel cannot complete the task with the available resources." However, after clicking OK it normally turns off the Filter anyways. At that point, I am able to enter information at a quicker pace. This occurs on both x64 and x86 Office 2010.

The spreadsheet itself is 439,949 rows deep and spans to column CU.
CTRL+Shift+End confirms the that no empty cells outside of the range are being utilized.

Anything I can do for this?

What are you using the spreadsheet for?

Are you using array formulas? If so, which ones? More than a few thousand array formulas can very noticeably slow computation and in many cases there are workarounds to them such as SUMPRODUCT.

I think my personal best was around 40MB. I usually get concerned around the 25MB mark and check to make sure I'm not using Excel as a database (that's what Access is for)

I am not sure of the specifics besides that it is combined sales volume over multiple periods. There are four columns that have a SUM forumla in every row, totaling around 1,791,248 SUM formulas. When the Filter is turned on, the spreadsheet becomes nearly unusable.

Any suggestions?

I'd export the whole thing to Microsoft Access.

Criteria based queries can sum, sort, count, pretty much anything Excel does, and without the instability.

My primary access table just hit 4,000,000 rows on 9/10 and it's still going strong.