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Am Donnerstag, 6. Dezember 2018, 10:27:31 CET schrieb Dale: |
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> Howdy, |
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> |
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> I mentioned in other threads that I'm doing some upgrades to my system. |
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> My first question is about a CPU upgrade. I currently have this for my |
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> CPU, from cpuinfo: |
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> |
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> AMD Phenom(tm) II X4 955 Processor |
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> |
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> I've bought but not yet installed a FX-8350 CPU. I have this in my |
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> make.conf file: |
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> |
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> CFLAGS="-march=native -O2 -pipe" |
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|
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Compiling the whole system with -march=native might lead to troubles, |
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especially when doing a CPU change. This option means that gcc is determining |
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the type of CPU automatically and adjusts the instruction set used to exactly |
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this CPU. Although, in your case, it is highly likely that your new CPU |
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understands all commands from the old, but I wouldn't bet on it. Its possible |
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that your existing software encounters problems like "illegal instruction" or |
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the like. Very bad if your compiler crashes after CPU replacement, then you |
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cannot emerge anything. I highly recommend using CFLAGS="-O2 -pipe" and |
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nothing more, the performance difference is, if measurable at all, negligible. |
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|
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> USE_CPU="fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov |
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> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt |
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> pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc |
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> extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic |
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> cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt |
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> nodeid_msr hw_pstate npt lbrv svm_lock nrip_save" |
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> |
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As someone else in this thread already mentioned, USE_CPU is not used. What |
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you're looking for is CPU_FLAGS_X86=..., which defines what cpu-specific options |
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will be enabled for packages supporting it and where it makes sense. See |
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package cpuid2cpuflags for details. |
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|
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Regards |
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Alex |