Top critical review
One person found this helpful
AMAZING power... if you can ACTUALLY get it to power on!
on December 5, 2014
This board has EVERYTHING going for it. mSATA with intel hybrid drive configuration (takes an SSD and a mechanical drive, and pairs them as a "super" hybrid drive), dual thunderbolt ports, plenty of I/O and PCIe and USB 3, and so on... It's even GREAT for running as a Hackintosh...
So why the low score?
This motherboard is PLAGUED by a power supply incompatibility that appears to be related to it's PowIR regulation technology. It appears that cheaper, single rail PSUs (under 700 watts) tend to work well with this board, but when you get into multiple rail PSUs of higher wattages, people are running into absolutely INSANE incompatibilities!
The motherboard often does not even complete the POST before powering down, whenever you try and power it up on an incompatible PSU. IF you can get it to stay on long enough, sometimes you can run the board flawlessly then!. On my current 950 W PSU, It can take over 100 pushes of the power button before it "sticks". Then I'll get MONTHS of up time! Suffered a power outage last month... a FEW HUNDRED power cycle attempts before it stayed on... It took OVER AND HOUR to power up, pressing power repeatedly, every time it shut itself down!
If you run the PSU under a tester , or another mobo, it's PERFECTLY FINE!!! If you run the Z77X-UP5 TH on a lower power, cheaper PSU, it starts first try! It's absolutely insane, and there are people who STILL don't believe it!
The general consensus seems to be that it has to do with power rail loading balance. Gigabyte used PowIR chips to regulate the power to the CPU, vs the traditional discrete Power MOSFETs controlled externally. Modern motherboards get 12 volts DC from the PSU, then use MOSFETs to regulate that power down to lower voltages for the CPU. Those lower voltage regulated sources have MUCH higher currents though. If you sent a motherboard 1.8 volts at 100 Amps, you'd need insanely thick wires and they'd get very hot. Passing low voltage, high current through wire will waste more of the total wattage available as heat, than passing high voltage, lower current. Its the same principal behind the high power transmission lines between the power station and your home. Likewise, in order to efficiently get power from the PSU to your CPU, the power is transmitted as higher voltage (12 volts), lower current. This is regulated to a lower voltage, but higher current, and this is where the PowIR technology of the Z77X-UP5 TH seems to falter...
Many computers now require more power on 12 volts than can be safely delivered by a single power source, so larger power supplies tend to have multiple 12 volt "rails". It just means you have extra 12 volt supplies side by side. Each one can provide it's own independent power to different parts, like you GPU, or your hard drives... or your CPU. It's believed that the PowIR technology might be faulting out when two different power rails supplying CPU power become unbalanced during power up due to one PowIR chip drawing more power than it's neighboring chips. Maybe the rise times of the different rails don't match, or maybe the loading is different enough to cause differing voltage drops, and the supplies take a fraction of a second to compensate.
I don't know... Whatever is happening... The motherboard glitches out and immediately shuts down, before the POST can even be performed! once you are passed the PSU's power rail rise times... It seems the motherboard may stay operational on the supply for MONTHS!
Apparently, the Thunderbolt ports won't work on a Hackintosh without first being "activated" from Windows. Some firmware thing, I think... Between this and the PSU issue, it makes the extra money I spent on this board to get Thunderbolt utterly worthless, as I built a stroked Mac OS Hackintosh machine, and don't run any type of Windows on it! I could have saved $100 and AVOIDED the PSU issues by going with a different mobo...
For all the trouble I've had going through different power supplies, to find one that works with it... I simply CAN NOT recommend this board.