DesignCAD memory useage

Here is some information about memory useage by DesignCAD.

I created a drawing with a file size of 83 Mbytes - a fairly large drawing - that had no blocks or symbols. The Windows Performance Monitor was used to monitor memory (RAM) useage.

The machine had 4 Gbytes of RAM, and the monitor reports only integer percentages (no factions) so the minimum RAM increment (1%) is 40 Mbytes.

State %RAM % Increase RAM useage
Vista 64 alone (plus Performance Monitor) 15% - ~600 Mbytes for Vista *
+DC and no drawing 16% +0% ~40 Mbytes or less for DesignCAD
+DC and drawing 27% +11% ~400 Mbytes for the 83 Mbyte file (4.8x)
+DC and Gouraud shaded drawing 29% +13% ~520 Mbytes for the Gouraud rendered file (6.3x)
+DC and Phong shaded drawing 30%/29% +13% ~520 Mbytes for the Phong rendered file (6.3x) ***

* Note: This is a neutered Vista - I turned off all the 240+ startup programs that Microsoft installs except the Performance Monitor. The initial Vista Installation used about 2 Gbytes of RAM. The trimmed version uses only 600-800 Mbytes (sometimes Performance Monitor reports 800 Mbytes).
** Phong shading with shadows and a 2048x2048 shadow mask.
*** Note: During shading memory use increased to 30%, but dropped to 29% after shading was complete.

DesignCAD is a RAM hog. To estimate the largest drawing (Mwork) you can work with subtract the amount of memory used by Windows (Mos) and DesignCAD (Mdc) from the total RAM in your machine (Mtotal):

Mwork = Mtotal - Mos - Mdc

Then divide Mwork by 6.3 (or 7 to be safe):

Mdrawing = Mwork/7

For example, in my machine Mtotal = 4000 Mbytes, Mos = 800 Mbytes, Mdc = 40 Mbytyes (or less).

Mwork = 4000 - 800 - 40 = 3160

3160/6.3 = 501.6
3160/7 = 451.4

In fact, I have tried to edit a 470 Mbyte file and DesignCAD locked up after the drawing was rendered in Phong with shadows. I have successfully worked with 350 Mbyte files on this machine. My next machine will have at least 16 Gbytes RAM!

If you work only in 2D you can probably get by with dividing Mwork by 5.