On 01.04.2012 13:05, Vitor Garcia wrote:
On Sun, 1 Apr 2012 04:45:08 -0400 Auguste Pop <auguste@gmail.com> wrote:
anyway, i think the following command can easily get the information you need: grep -c processor /proc/cpuinfo
This command will make a few 2 Cores processor with some kind of virtual processing technology (like hyper-threading) to be counted as a 4 cores processor.
Which is totally fine.
Then you just have to multiply both numbers and you know how many "real cpus" you have on the system. Otherwise you may be counting virtual processors, which shouldn't be used for heavy stuff such as compiling.
Simple tests (building readline because it's small) with -j4 and -j8 on my i7-920 show that -j8 is around 20% faster than -j4. IIRC wikipedia states that HT core can increase performance by up to 30%. -- Florian Pritz