Why doesn't WD Velociraptor speed up my VC++-compilation significantly?

Question

Several people round here recommended switching to the new WD Velociraptor 10000rpm harddisk. Also magazine articles praise the performance. I bought one and mirrored my old system to it. The resulting increase in compilation-speed is somewhat disappointing:

• On my old Samsung drive (SATA, 7200), the compilation time was 16:02.
• On the Velociraptor the build takes 15:23.

I have a E6600 with 1.5G ram. It's a C++-Project with 1200 files. The build is done in Visual Studio 2005. The acoustic managment is switchted off (no big difference anyway).

Did something go wrong or is this modest acceleration really all, I can expect?

Edit: Some recommended increasing the RAM. I did now and got a minimal gain (3-5%) by doubling my RAM to 3GB.

Answer 1

Are you using the /MP option (undocumented, you have to enter it manually to your processor options) to enable source-level parallel build? That'll speed up your compile much more than just a faster harddisk. Gains from that are marginal.

Answer 2

Visual Studio 2005 can build multiple projects in parallel, and will do so by default on a multi-core machine, but depending on how your projects depend on each other it may be unable to parallel build them.

If your 1200 cpp files are in a single project, you're probably not using all of your CPU. If I'm not mistaken a C6600 is a quad-core CPU.

Dave