Few things ruin a workday faster than an AutoCAD out of memory error — often right before a deadline. The message usually appears when saving, plotting, or regenerating a large drawing. The good news: in most cases the drawing is fine, and the fix takes minutes. Here are the seven most common causes, in the order we see them.
AutoCAD is conservative about giving memory back to Windows. After hours of regen, undo, hatching and copy-paste, it can hold hundreds of megabytes — even gigabytes — it no longer needs. This is the single most common cause, and the reason a restart "fixes" everything.
Copies from client files bring blocks, layers, linetypes, dimension styles and regapps you never use. Each one stays in memory while the drawing is open. Run -purge (note the hyphen, it opens the command-line version) repeatedly, then choose Regapps and All.
A single 50 MB scanned site plan attached as an image can consume several times its file size in RAM. Underlays are convenient but expensive. Unload what you are not currently working on, or convert them to lightweight vector references.
Every attached reference is fully loaded into memory unless demand loading is on. Nested xrefs multiply the cost: one host file may silently pull in a dozen others.
Solids, surfaces, and associative hatching with tiny spacing generate huge amounts of geometry. Visual styles like Realistic also keep extra GPU and system memory busy.
Modern AutoCAD is 64-bit, so the old 4 GB ceiling is gone — but Windows still needs room to breathe. If AutoCAD plus your browser, mail client and PDF reader exceed physical RAM, the system starts swapping and AutoCAD throws the error.
Audit errors, bad scale lists and broken custom objects inflate memory and often cause crashes alongside the memory error. Run AUDIT with Fix errors = Yes, or RECOVER on the file.
-purge → All (run it 2–3 times).AUDIT and let it fix errors.XREF → Unload).Restarting works, but it costs you your session, your layer states and your flow. CadMemFree reclaims idle memory from inside AutoCAD, so you can keep working in the same drawing. The free tier includes 14 days of full features, then 10 automatic cleans per day plus 10 manual cleans — free forever.
Often yes. Check the %TEMP% folder and .sv$ files, and use the Drawing Recovery Manager (DRAWINGRECOVERY).
Sometimes. If it happens on small drawings with a fresh session, look at RAM, GPU drivers and the page file first.
No. It only releases memory AutoCAD is holding but not using; it never touches geometry, layers or xrefs.
Tired of the out-of-memory dialog? Download CadMemFree free or see pricing.