![]() ![]() Older macs with a core1 *probably do not throttle the unit based on power availability (any more than it regularly does via “battery vs power adapter” ) - iOS introuced this with the iPhones to limit crashing, but this was a decade after the core1 was around. It is easy to tell this, because booting takes 4 times longer than normal. This SMC throttling is fixed and unwavering at 800mhz. The SMC chooses to throttle the CPU at boot, and there is also a pref file flagging the enforcement as well (how exactly they interact is difficult for me to understand). Whatever happens, it is sudden and unrecoverable. It directly talks to the CPU, using calls the CPU itself understands - so something about those calls crashes the CPU itself, it seems. The tool Intel released instantly hangs the machine if forced to open on a core1. ![]() ![]() I never found a way to measure actual CPU speed on core1 units. Still interested in how to read the CPU frequency directly. Now it is stuck in full-fan bypass mode - I’ll have to put the MLB back in the top case just to reset the SMC. any other suggestions?Įdit2: Putting it into SMC bypass mode did show me the CPU was being throttled by the SMC - the geekbench 4 score went up 40% in bypass. This is indirect, but will let me know if the SMC is CPU throttling me. 300% Kernel_task + 80% CPU throttling is obvious when you can see the frequency "0.8 GHZ" in IPG.Īny ideas - directly or indirectly - on how to check the actual CPU frequency? They are running Yosemite.Įdit: While thinking about this further, I'm going to try booting it into SMC bypass mode and re-running geekbench to see if the scores change. My previous project with an 2013 iMac revealed the double-throttling nature of the SMC (CPU throttle + excessive kernel_task activity), but I was able to easily check the CPU status with IPG. I can infer I am getting throttled by seeing Geekbench 4 readings about 30-40% lower than the scores posted (1200/2000 CPU geek bench 4 score for my 2.53 Late 2008 MBP model currently) - and the temperature stays cooler than I expect under "100%" load. I can easily check the kernel_task, and see the CPU load in Activity Monitor, but finding the actual working frequency is elusive (not the number stated in About this Mac). SMC throttling can involve both kernel_task AND lower CPU frequency. I need to know if I am getting SMC throttled. All utilities (iStat menus, for example) depend on IPG for the **actual** frequency data, so no 3rd party "system monitoring" apps are useful at all. installing IPG manually out of it's package crashes the computer on app launch. they are first generation Core processors, and are not supported by Intel Power Gadget (IPG). I'm working on a mashup project with older MacBooks / MacBook Pros - Late 2008 models (the first unibody ones). ![]()
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