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amd [2018/12/01 14:57] (current) – created - external edit 127.0.0.1
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 +====== AMD AM3+ FX ======
 +===== BIOS Remarks =====
 +==== Best tradeoff (speed, low power) ====
 +**HPC Mode** Must be ON! If not CPU cannot reach full speed under load (bad multicore performance)\\
 +**APM** Must be ON! If not Turbo Boost won't work (bad singlecore performance)\\
 +
 +==== Best multicore (high power) ====
 +**APM OFF**
 +
 +---
 +==== Overclocking ====
 +If it's in TDP limit everything is fine, but when you raise voltage you must turn off APM which guard TDP.
 +My advice -> don't raise voltage.
 +If APM is not disabled, CPU is throttling to stand in TDP. If disabled, power consumption reach high levels constantly.
 +
 +==== Sample Table ====
 +Assume 3.5 GHz as base frequency
 +^ HPC ^ APM ^ Remark ^
 +| ON | ON | System running on 3.5 GHz, sometimes drops to 1.4 GHz (TDP) |
 +| OFF | ON | System running on 3.5 GHz, often drops to 2.9 GHz (TDP) |
 +| ? | OFF | System cannot use Turbo Core, running at 3.5 GHz with very high power usage |
 +C6, Cool n Quiet - always enabled there's no reason to turn it off\\
 +HPC Mode lock CPU in three states Turbo-boost, Normal, Low-power.
 +
 +====== Microcode Update AM3+ ======
 +Microcode update is hard and is located in -> **AmdProcessorInitPeim** <- UEFI block\\
 +Can be edited directly via Hexa editor (pasting new code over approx 3kB size for newer CPUs)\\
 +Tools: MMTool, UEFITool, MC Extractor
 +
 +Sample -> Updated AMD microcode to 6000852 (Solved NMI bug and SPECTRE)\\
 +{{:am3update.png?nolink|}}
 +[[https://janforman.org/files/BIOS-and-ROM/BIOS_2018_Gigabyte-990X-GamingSLI.zip|Download GIGABYTE GA-990X-Gaming SLI-CF BIOS with new microcode 6000852]]
 +====== Cinebench ======
 +{{:cinebench-fx8300.png?nolink|}}
 +
 +====== CryptoNight Performance ======
 +343.100 H/s
 +
 +====== Bulldozer / Piledriver Die ======
 +8-core FX-8xxx CPU have 4 modules so in fact this hurts performance.\\
 +If you completely load two cores in one module performance is not 200%, but aprox. 160% (Fetch and FPU unit are shared between them).\\
 +FPU unit can split into two pieces for most work, but have only one scheduler. L1 instruction cache is shared too\\
 +8-core performance gives you not 800% but approx. only 640% (little faster than natural 6 core CPU - Phenom II X6) in full load.
 +{{:amd-die.jpg?nolink|}}
  
amd.txt · Last modified: 2018/12/01 14:57 by Jan Forman