Firmware And Overclocking
The Plus UEFI starts in Asus' typical EZ Mode with only the most basic options available on a single page, such as boot drive order, EZ System Tuning and fan control. The EZ tuner set the CPU to 46 x 100 MHz at 1.32V, which is pretty aggressive and ultimately unstable with our test i7. You can also switch to a power saver mode that limits CPU speed and voltage. Pressing F7 gets you to the advanced mode that most users will need. Originally it seemed the Plus didn't allow you the option to start the UEFI in advanced mode. A little more digging found that setting at the bottom of the Boot page. Unlike the OCF, the Plus doesn't offer FHD support.
Advanced mode has a nice layout that includes a system monitor on the right side. The bottom panel acts as a permanent tooltip that gives you extra info regarding the setting you have highlighted. These two sections are visible regardless what page and section you're in. The Plus also has Asus' usual Quick Note and exit confirmation page that lists every setting that was changed before you commit those changes. Altogether, it's a very informative presentation. Asus' MyFavorite feature isn't quite as simple as ASRock's but it's more robust as you can browse through the entire menu and bookmark every setting.
The Plus offers very granular power delivery controls DIGI+ VRM. It might be more than what casual overclockers want, but for those who want very fine control over their CPU voltage, this is a great offering. Other features include eight configuration save slots (these can also be imported and exported to USB), three-point fan curve control (with both PWM and voltage control methods), and an EZ Tuning Wizard for more detailed automatic overclocking than the basic mode's high-performance setting. The Wizard set the CPU clock to 44 x 102 MHz on auto voltage and DDR3-2720 for the RAM (using DDR3-2666 multipliers). The RAM was ultimately not stable at these speeds, though the CPU had no problem.
Manual overclocking posed no significant difficulties. Minor experimentation showed 45 x 101 MHz was as fast as I could push it. The finer power control helped compensate for the smaller VRM and heat sink, but it can only do so much for this particular i7. BCLK overclocking on the Plus is thoroughly impressive. I took it up to 111 MHz before I noticed the board automatically switches the CPU straps to compensate. Even when locking down the strap, I hit 108 MHz at the 1:1 ratio. Using the 1.25 and 1.67 straps I was able to hit 144 MHz and 189 MHz respectively (those corresponded to a 115 MHz and 113 MHz DMI, respectively).
The Plus did exhibit one curious behavior with Intel's Turbo Boost. Normally the 4790K will throttle up to 4.4 GHz on a single thread and 4.2 GHz with all four cores loaded. Left on pure defaults the Plus would only engage Turbo Boost under a single thread. Everything else dropped the clock to 4.0 GHz. After some fiddling with the overclock Wizard then disabling, it looked like Turbo Boost was getting treated normally. As most people getting this board will not leave the CPU multiplier on automatic settings, this is of little concern.
RAM overclocking was disappointing on the Plus. The fastest I could reach with two modules was DDR3-2814 (using DDR3-2800 multipliers and a 100.5 MHz BCLK). Four modules wouldn't even boot at 2800 and weren't stable at 2666. I did get a nice 2400 overclock with a 104.5 MH BCLK for DDR3-2508.
The included applications and utilities are Asus' usual HomeCloud and AI Suite III. The former is a file and media sharing software for your home computers and devices, but the latter is what most enthusiasts care about. As we've covered it in many Asus motherboard reviews before, I won't go into it a great deal here. AI Suite III allows you to monitor and tune the fan and power profiles, change the CPU multiplier, voltage, and BCLK, and monitor the system sensors. You can modify RAM voltage in it, but not RAM timings or frequency.
BIOS Frequency & Voltage Settings (For Overclocking)
|Base Clock||80-300 MHz (0.1 MHz)|
|CPU Multiplier||8x-800x (1x)|
|DRAM Data Rates||800-3400 (200/266.6 MHz)|
|CPU Vcore||0.001-1.920V (1 mV)|
|VCCIN||0.80-2.70V (10 mV)|
|PCH Voltage (1.05V)||0.735-1.500V (5 mV)|
|PCH Voltage (1.5V)||1.185-2.135V (5 mV)|
|DRAM Voltage||1.185-1.800V (5 mV)|
|CAS Latency||1-31 Cycles|