Question 1

How does FastMM4 compare to the default Delphi memory manager?

Accepted Answer

FastMM4 offers superior performance with lower overhead (5-10% per block), better multi-threaded scaling, and built-in debugging like memory leak detection. However, it requires setup and may not be compatible with all third-party libraries that depend on the default manager.

Question 2

Is FastMM4 compatible with all Delphi versions?

Accepted Answer

Yes, FastMM4 supports Delphi 4 or later, C++ Builder 4 or later, and Kylix 3, as per the README. But for newer versions, you should check for updates or community patches to ensure full compatibility.

Question 3

How to set up FastMM4 for memory leak detection in development?

Accepted Answer

Enable the conditional defines in FastMM4Options.inc to report memory leaks on shutdown, and set checks to run only when Delphi is detected. Place FastMM4 as the first unit in your .dpr file to ensure it initializes before other units.

Question 4

Can FastMM4 be used in C++ Builder projects effectively?

Accepted Answer

Yes, but you must follow the specific instructions in FastMM4BCB.cpp for integration. It provides similar benefits as in Delphi, but setup might differ due to C++ Builder's compilation model.

Question 5

FastMM4 vs. other memory managers for Delphi: which is better?

Accepted Answer

FastMM4 is often preferred for its balance of speed, low fragmentation, and debugging tools. However, alternatives like ScaleMM or TBB might offer different trade-offs in specific scenarios, such as extreme multi-threading or minimal footprint.

Question 6

How to enable large address space support with FastMM4?

Accepted Answer

Use the EditBin tool to set the LARGE_ADDRESS_AWARE flag in the EXE header, or in Delphi 6+, add the compiler directive {$SetPEFlags $20} to your .dpr file, allowing up to 3GB on 32-bit Windows and 4GB on 64-bit.

Question 7

Does FastMM4 work with third-party DLLs that don't use it?

Accepted Answer

No, for shared memory operations, both the application and DLL must be compiled with FastMM4. Otherwise, memory passed between them (like long strings) may cause issues due to mismatched memory managers.

FastMM

What is FastMM?

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