Amdctl reports incorrect frequencies

[echaskaris]

I have AMD FX-4170. Top frequency is 8400 mhz, but the CPU is rated for 4200.

[kevinlekiller]

It might be setting the wrong FSB speed, some bulldozer CPU's are 100 MHz, some are 200, it multiplies the FSB by the multiplier to get the frequency (ex 42 * 100 = 4200).

[kevinlekiller]

https://github.com/kevinlekiller/amdctl/blob/master/amdctl.c#L386

Is your CPU revision between 0 and 0f ?

[echaskaris]

What field is the revision in /proc/cpuinfo?

[echaskaris]

/proc/cpuinfo contents: processor : 0 vendor_id : AuthenticAMD cpu family : 21 model : 1 model name : AMD FX(tm)-4170 Quad-Core Processor stepping : 2 microcode : 0x600063e cpu MHz : 1630.357 cache size : 2048 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf pni pclmulqdq monitor ssse3 cx16 sse4_1 sse4_2 popcnt aes xsave avx lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt fma4 nodeid_msr topoext perfctr_core perfctr_nb cpb hw_pstate ssbd ibpb vmmcall arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold bugs : fxsave_leak sysret_ss_attrs null_seg spectre_v1 spectre_v2 spec_store_bypass bogomips : 8437.44 TLB size : 1536 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm 100mhzsteps hwpstate cpb

[kevinlekiller]

Yeah, you're in between 0 and 0f (model : 1), I wasn't sure about the math on those, because the manual says they have a FSB of 200 MHz, if you look through, search for cpudid / cpu fid / nbdid / nbfid / corecof, you will find some explanations of how the CPU frequency is calculated, https://www.amd.com/system/files/TechDocs/42301_15h_Mod_00h-0Fh_BKDG.pdf

If I have time this weekend, I will look to see how it is done on these models.

[echaskaris]

Thanks!

[kevinlekiller]

You could try commenting out this section https://github.com/kevinlekiller/amdctl/blob/master/amdctl.c#L390-L392 and see if any values look off.

[echaskaris]

They look okay without that section. (4200 base, 4300 boost)

[kevinlekiller]

Alright, the only thing I wonder is if it affects the north bridge clock calculations, maybe it requires the math on 200 MHz for north bridge calculations and 100 MHz for core clock calculations ?

Referring to this block of code I mean (which shows north bridge information - if refclck is now 100, do those numbers output wrong?): https://github.com/kevinlekiller/amdctl/blob/master/amdctl.c#L318-L328

[kevinlekiller]

If so, this line might need to be changed: https://github.com/kevinlekiller/amdctl/blob/master/amdctl.c#L328

(((cpuModel >= 0x00 && cpuModel <= 0x0f) ? REFCLK * 2 : REFCLK) * (nbdid + 0x4) / pow(2, nbfid))

[priand1]

Hi Kevin, thanks for amdctl. It works quite well. I also have the problem that echaskaris has, but with an FX-8320. I was able to fix it by making the two changes mentioned above in amdctl.c: https://github.com/kevinlekiller/amdctl/issues/14#issuecomment-502109322 and https://github.com/kevinlekiller/amdctl/issues/14#issuecomment-502113532

My /proc/cpuinfo: processor : 7 vendor_id : AuthenticAMD cpu family : 21 model : 2 model name : AMD FX(tm)-8320 Eight-Core Processor stepping : 0 microcode : 0x6000852 cpu MHz : 1399.187 cache size : 2048 KB physical id : 0 siblings : 8 core id : 7 cpu cores : 4 apicid : 23 initial apicid : 7 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core perfctr_nb cpb hw_pstate ssbd ibpb vmmcall bmi1 arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold bugs : fxsave_leak sysret_ss_attrs null_seg spectre_v1 spectre_v2 spec_store_bypass bogomips : 6999.84 TLB size : 1536 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm 100mhzsteps hwpstate cpb eff_freq_ro

Thank you, Andreas