My two cents worth : Update gcc before changing any hardware.
With gcc somewhat current, try this on the replacement CPU. This gives a listing of all CPU supported compiler flags. Including -mtune / -march :) gcc -c -Q -march=native --help=target sample of output : -msse4 [enabled] -msse4.1 [enabled] -msse4.2 [enabled] -msse4a [enabled] -msse5 -msseregparm [disabled] -mssse3 [enabled] -mstack-arg-probe [disabled] -mstack-protector-guard= tls -mstackrealign [disabled] -mstringop-strategy= [default] -mstv [enabled] -mtbm [enabled] -mtls-dialect= gnu -mtls-direct-seg-refs [enabled] -mtune-ctrl= -mtune= bdver2 -muclibc [disabled] -mveclibabi= [default] -mvect8-ret-in-mem [disabled] -mvzeroupper [enabled] -mx32 [disabled] -mxop [enabled] -mxsave [enabled] -mxsavec [disabled] -mxsaveopt [disabled] -mxsaves [disabled] This will give you the L1 / L2 cache/line/size parameters : gcc -### -march=native /usr/include/stdlib.h sample of output : gcc version 7.3.0 (Gentoo 7.3.0-r3 p1.4) COLLECT_GCC_OPTIONS='-march=native' /usr/libexec/gcc/x86_64-pc-linux-gnu/7.3.0/cc1 -quiet /usr/include/stdlib.h "-march=bdver2" -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -msse4a -mcx16 -msahf -mno-movbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mlwp -mfma -mfma4 -mxop -mbmi -mno-sgx -mno-bmi2 -mtbm -mavx -mno-avx2 -msse4.2 -msse4.1 -mlzcnt -mno-rtm -mno-hle -mno-rdrnd -mf16c -mno-fsgsbase -mno-rdseed -mprfchw -mno-adx -mfxsr -mxsave -mno-xsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves -mno-avx512dq -mno-avx512bw -mno-avx512vl -mno-avx512ifma -mno-avx512vbmi -mno-avx5124fmaps -mno-avx5124vnniw -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mno-rdpid --param "l1-cache-size=16" --param "l1-cache-line-size=64" --param "l2-cache-size=2048" "-mtune=bdver2" -quiet -dumpbase stdlib.h -auxbase stdlib -o /tmp/ccQiaXih.s "--output-pch=/usr/include/stdlib.h.gch" Reference Link : https://wiki.gentoo.org/wiki/GCC_optimization On 12/6/18 3:27 AM, Dale wrote: > Howdy, > > I mentioned in other threads that I'm doing some upgrades to my system. > My first question is about a CPU upgrade. I currently have this for my > CPU, from cpuinfo: > > AMD Phenom(tm) II X4 955 Processor > > Those were put there ages ago, likely when I built and installed Gentoo > on this rig. Do I need to change those to something that is compatible > with both CPUs and then change to the new CPU after it is installed? Or > will the new CPU be close enough that it won't matter? Right now, I > don't know for sure what the new CPU supports or doesn't. >