Hi!> To have a bit of a work around for the Intel Meltdown bug (yes, no > Spectre), I wanted to try out some AMD based CPUs. So far so good using > a SuperMicro H11SSL-i. A decent server board using an Epyc CPU. All > the things you need and expect for a server grade MBOn the plus side: 16+16 cores, on the minus: A low CPU tact of 2.2 GHz. Would a box like this be better for a package build host instead of 4+4 cores with 3.x GHz ? -- pi at opsec.eu +49 171 3101372 2 years to go !
Mark Linimon
2018-Feb-14 11:10 UTC
package building performance (was: Re: FreeBSD on AMD Epyc boards)
On Wed, Feb 14, 2018 at 09:15:53AM +0100, Kurt Jaeger wrote:> On the plus side: 16+16 cores, on the minus: A low CPU tact of 2.2 GHz. > Would a box like this be better for a package build host instead of 4+4 cores > with 3.x GHz ?In my experience, "it depends". I think that above a certain number of cores, I/O will dominate. I _think_; I have never done any metrics on any of this. The dominant term of the equation is, as you might guess, RAM. Previous experience suggests that you need at least 2GB per build. By default, nbuilds is set equal to ncores. Less than 2GB-per and you're going to be unhappy. (It's true that for modern systems, where large amounts of RAM are standard, that this is probably no longer a concern.) Put it this way: with 4 cores and 16GB and netbooting (7GB of which was devoted to md(4)), I was having lots of problems on powerpc64. The same machine with 64GB gives me no problems. My guess is that after RAM, there is I/O, ncores, and speed. But I'm just speculating. mcl
On 2/14/2018 3:15 AM, Kurt Jaeger wrote:> > On the plus side: 16+16 cores, on the minus: A low CPU tact of 2.2 GHz. > Would a box like this be better for a package build host instead of 4+4 cores > with 3.x GHz ?jail server. Lots of processes ---Mike>-- ------------------- Mike Tancsa, tel +1 519 651 3400 x203 Sentex Communications, mike at sentex.net Providing Internet services since 1994 www.sentex.net Cambridge, Ontario Canada