buildpkg/quickpkg and single/dual CPU systems

Sieg · Tux's lil' helper Joined: 07 Oct 2002 Posts: 87

Hi,

I'm about to install Gentoo on 4 dual Xeon's and 2 single Xeon systems. We will often need to use buildpkg or quickpkg to deploy packages from the dev/test servers to the production servers. What I was wondering is what would be the impact of building a package on a dual cpu system that would have MAKEOPTS=-j5 and then running it on only a single CPU systems (they have HT enabled)?

Would this cause any problems since there would not be a second CPU? Would there be any performance impact?
Or would it be better to build them using MAKEOPTS=-j3?

It would be great if there would not be any impact at all, but I'd like to know!

They will all be Xeons with HT, so CPU architechture for all of them will be the same.

Thanks a lot for any input considering this!

robmoss · Posted: Sat Sep 06, 2003 1:22 pm Post subject:

Hmmm... well, I *think* that -j5 only affects how many instances of the compiler run at once, so as far as I know there would be no problems. But if I were you I'd wait for someone who really knows what they're talking about to reply...!

Sieg · Tux's lil' helper Joined: 07 Oct 2002 Posts: 87

Thanks for the info! Hopefully someone can confirm this but I guess it would make sense reading the description of MAKEOPTS in the make.conf file.

Ox- · Guru Joined: 19 Jun 2003 Posts: 305

From stat's that I've seen (sorry can't remember the link now) it doesn't hurt anything to go too high with -j. It's just a case of diminishing returns. Seriously diminishing, as in the line almost goes flat... but as long as your number is still within reason it doesn't go down

Sieg · Tux's lil' helper Joined: 07 Oct 2002 Posts: 87

Thanks. Would there be anything else to lookout for? Or if someone could confirm what robmoss2k said, it would be really appreciated!