We found that memory is at some point the bottleneck; at link time, the process takes a huge amount of memory, more than we used to have on our computer, and when the memory is full it starts to swap memory pages in and out! That took a long time. Increasing the memory of our machines, reduced the link time ! Max.

Have a look at MSDN Magazine (online somewhere at Microsoft.com). There was an article about it a few years ago. There's also code from product support. Keywords might be "NTFS5".

I am not sure, but this can be OS/display driver dependant: Create 2 memory DCs. Select each bitmap in his corresponding DC, then do the stretchblt between the DCs. The bitmap in the target DC will be modified. You can the bitblt the taget DC contents into another DC (like the DC of a control/window) or unselect the bitmaps, and do what you wish with the modified one.