Underclocking i5 Haswell for ultra-quiet slim mini-ITX HTPC Hackintosh?

[johnny5k]

I'm planning my first Hackintosh build, in a slim Mini-ITX case, primarily for watching (1080p) and converting video. Low noise is a top priority, and a small cpu cooler is necessary to fit the case. I was looking at using a i5-4690T (it's only 45W), but I've read that the "T" versions are just underclocked versions of the un-lettered CPUs, and I should instead underclock the regular CPU (i5-4690 is 84W). Will this work for a OSx86 machine? I plan on using an ultra-low-profile cooler (ID-Cooling IS-25i) and no case fan, if I can get away with it, with the GA-H97N-WiFi motherboard (GA-Z97N if need for changing clock speed). Any help would be appreciated. Thanks.

[Hangten]

I would just lower the voltage on the cpu and set the speed depending on the heat being generated. IMO use the i5 4690. Most motherboards have setting for thermal monitoring so you would be hard pressed to damage the chip. Worst case is freezing and a reboot if your thermals go too high. You can also change the bus speed in Clover and multi in your DSDT or SSDT to give you a desired speed in OS X. And look into the power management stuff here on insanelymac it will allow you to see that you can adjust how many speed steps you have access too. I personally only have like three and thats fine with me. 12, 24, 37 on the multi. 

 

What about just buying an Intel NUC? I can't imagine you would have any issues with your Mini-ITX case if a NUC is able to run at reference clock speeds. Considering a higher end NUC appears to run fine with a cpu thats no slouch. 

[johnny5k]

I would just lower the voltage on the cpu and set the speed depending on the heat being generated. IMO use the i5 4690. Most motherboards have setting for thermal monitoring so you would be hard pressed to damage the chip. Worst case is freezing and a reboot if your thermals go too high. You can also change the bus speed in Clover and multi in your DSDT or SSDT to give you a desired speed in OS X. And look into the power management stuff here on insanelymac it will allow you to see that you can adjust how many speed steps you have access too. I personally only have like three and thats fine with me. 12, 24, 37 on the multi. 

 

What about just buying an Intel NUC? I can't imagine you would have any issues with your Mini-ITX case if a NUC is able to run at reference clock speeds. Considering a higher end NUC appears to run fine with a cpu thats no slouch. 

 

Thanks for the response! I looked at NUCs but I really want to include my existing 6TB 3.5" drive, and a 2.5" SSD boot, both internally. If NUC boards had 2 sata ports it could work, but they only have one, and I don't want to use USB3 or an external case. I could use one SATA and one mSATA/M.2 drive on a NUC board, but I've seen that they can be a pain to get working with OS X; and this being my first hackintosh, I don't think I want to deal with that. There's also a mSATA to SATA adapter, but I imagine that would have the same (or worse) issues.

[johnny5k]

I did some figures, comparing the i5-4690 to the i5-4690T. Intel reduced the clock speed by 30% to get from 3.5 to 2.5Ghz, and the voltage by 13% to get the TDP down from 84 to 45W. Can I make similarly sized changes to the non-lettered processors? Or would changing the values that much make the system unstable? The last thing I want is an unstable system. Ideally, I'd like to go down to 35W, which would take a 37% underclock and 19% undervolt (or another similar combination w/more underclock & less undervolt). Does that sound doable?