shrieken213 Posted February 9, 2014 Share Posted February 9, 2014 So I've been running Mavericks 10.9.1 via vanilla install on this build for a couple weeks now: Gigabyte GA-Z87MX-D3H Gigabyte GTX 770 4GB i7-4770K And for a while I never even needed boot flags to boot properly. Now I tried to overclock the CPU, and for a while OS X recognized this as well since HWMonitor was able to see both the increased Vcore and multiplier fine. I dual boot with Windows, so I also have to stress test the overclock for stability. I found that 4.4Ghz was extremely unstable, so I raised the VRIN and VRING to 1.9V and 1.155V respectively (~0.1V bump each), turned off all C-states and EIST. Now the computer can pass 12+ hours of prime95 blend. But the problem is with OS X. Whenever I boot with this configuration, I get a kernel panic before anything can load: "Unable to find driver for this platform: "ACPI/"" or something of the like. Every time the source of the crash is com.driver.AppleACPIPlatform. I read that this might be a problem with DSDT, but right now I am running a DSDT-free installation so that can't be it. I tried booting with acpi=no/null/off/etc., -x, -f, etc. to no avail. What is even more interesting is that now OS X cannot even handle ANY overclock; it will only boot in optimized defaults. Whereas before OS X could handle sizable bumps in multiplier and Vcore (47x and 1.36V), even a 1x bump or 0.01V increase now causes a kernel panic with the same aforementioned error. I tried using the patched AppleACPIPlatform.kext by crunk, and that didn't help at all either. Does anyone have any idea why this is happening? Link to comment Share on other sites More sharing options...
shrieken213 Posted February 9, 2014 Author Share Posted February 9, 2014 I just experimented with the multipliers. It seems I cannot boot to OS X when it is clocked beyond 4.4Ghz. I turned the multiplier down by 1 (4.3Ghz) and OS X boots fine. What's even more interesting is that at 4.5Ghz, Chameleon fails to boot at all, giving a memory allocation error at address 0x320 and the "This is a non recoverable error! System HALTED!!!" message. This leads me to believe that perhaps it is not OS X but rather Chameleon that is not able to keep up with the high clocks. Memory is currently clocked at 1600Mhz; I'll try boosting the memory frequency to see if it solves the allocation error. Link to comment Share on other sites More sharing options...
Maniac10 Posted February 9, 2014 Share Posted February 9, 2014 Perhaps you're loading a SSDT which doesn't correspond with the overclocked values? You can try Clover to discard a bootloader problem. Link to comment Share on other sites More sharing options...
aphex6b Posted February 10, 2014 Share Posted February 10, 2014 the problem is not with osx or chameleon, both will let you boot 4.40 ghz fine. My guess is the "Unable to find driver" / acpi related boot errors are due to wrong boot loader settings (GenerateC / PStates ), or non correct smbios definition.Also the most exciting new features in the Z87 / mavericks are based on energysaving, what i meant is oc'ing your 4770K is fine but no need to turn the energy saving features off imho Link to comment Share on other sites More sharing options...
shrieken213 Posted June 19, 2014 Author Share Posted June 19, 2014 the problem is not with osx or chameleon, both will let you boot 4.40 ghz fine. My guess is the "Unable to find driver" / acpi related boot errors are due to wrong boot loader settings (GenerateC / PStates ), or non correct smbios definition.Also the most exciting new features in the Z87 / mavericks are based on energysaving, what i meant is oc'ing your 4770K is fine but no need to turn the energy saving features off imho The issue was the C-state and P-state generators. Once those are disabled, the Hack was able to boot correctly, although the clock speed under "About This Mac" was capped at 4.3Ghz. Link to comment Share on other sites More sharing options...
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