The larger a VC++ project is (or any project for that matter) the more time it takes to build. If you have solutions with many large projects the build times could get into your way. Starting a rebuild and going to lunch was a common scenario for me, as building took 20-25 minutes. Of course, you don’t rebuild everything all the time, but sometimes is enough to change something in a header somewhere deep inside the dependency web and trigger a rebuild of many or all the projects in a solution.<\/p>\n
Using compiler switches and other tricks I managed to reduce the build time with about 50% or more (the percent of speedup is similar on different machines, regardless of the previous build times on those machines). Replacing the hard disk with an SSD provided an additional 25% speed. My full build times have decreased from 20-25 minutes to about 7 minutes.<\/p>\n
First off all, Visual Studio enables parallel projects builds<\/strong> by default. As long as your projects don’t have dependency and can be built in parallel, it is possible to have up to 32 projects built at the same time. By default the number of projects built in parallel is set to the number of available cores. This option can be change from Tools > Options > Projects and Solutions > Build and Run.<\/p>\n
Another strategy for increasing the build times is to reduce the number of times framework headers (STL, MFC, ATL, etc.) or headers from your project that do not change often and are included in many places are included into the various source files of your projects. These headers can be put in the pre-compilead header, and therefore compiled just once. <\/p>\n
The next table shows the additional speed-up gain for several projects after moving framework headers to the pre-compiled header of each project.<\/p>\n
\n
\n
Before<\/th>\n
After<\/th>\n<\/tr>\n
\n
Release<\/th>\n
Debug<\/th>\n
Release<\/th>\n
Debug<\/th>\n<\/tr>\n
\n
00:00:37.32<\/td>\n
00:00:25.23<\/td>\n
00:00:32.79<\/td>\n
00:00:19.24<\/td>\n<\/tr>\n
\n
00:00:12.16<\/td>\n
00:00:07.47<\/td>\n
00:00:04.90<\/td>\n
00:00:02.41<\/td>\n<\/tr>\n
\n
00:00:51.35<\/td>\n
00:00:50.72<\/td>\n
00:00:44.15<\/td>\n
00:00:37.25<\/td>\n<\/tr>\n
\n
00:00:24.41<\/td>\n
00:00:20.16<\/td>\n
00:00:20.19<\/td>\n
00:00:20.16<\/td>\n<\/tr>\n
\n
00:01:15.40<\/td>\n
00:01:14.07<\/td>\n
00:01:14.10<\/td>\n
00:01:10.56<\/td>\n<\/tr>\n
\n
00:01:34.66<\/td>\n
00:01:17.97<\/td>\n
00:01:23.60<\/td>\n
00:01:22.15<\/td>\n<\/tr>\n
\n
00:01:11.99<\/td>\n
00:00:54.07<\/td>\n
00:01:11.70<\/td>\n
00:00:43.20<\/td>\n<\/tr>\n<\/table>\n
The speed-up gain by using these techniques may vary depending on your project specifics. In some cases the gain may not be significant or the build time may actually increase. You should play around with these settings and enable them only when they help you.<\/p>\n
In summary, some of the strategies that can help increase your build times are:<\/p>\n
\n
break dependencies between projects they can be built in parallel<\/li>\n
if you have large projects try to break them in smaller, independent projects; the more such projects you have the more work can be done in parallel<\/li>\n
use multi-processor compilation (\/MP) for C++ projects to enable compiling multiple translation units at the same time<\/li>\n
move framework headers (STL, MFC, ATL, etc.) and other headers that do not change and are included all over your project to the pre-compiled header<\/li>\n
use a SSD and keep your sources on it<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
![\"vcbuild1\"](\"http:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2013\/09\/vcbuild1.png\")
<\/a><\/p>\n