Section 1 Subsystems
Memory -
Memory performance is very important on a motherboard, especially when you have a CPU with multiple cores and threads. If you have slow memory your cores and threads can become starved for data to execute. To test memory performance we run both Sisoft’s SANDRA and AIDA64. These two combine to not only give us accurate numbers but to validate each other. For testing at stock speeds the memory is hard set to 16000MHz while overclocking testing is done at the highest stable speed for the voltage of 1.55v this is due to the different memory dividers for each CPU. As such, the memory speeds will vary greatly. This means that the overclocked numbers are a little misleading and while they can show a trend are really only included to show if a board has a problem with memory performance at high clockspeeds. 
The Asus Z97I Plus comes in just behind the two Z87 boards that we have had in the lab. We would have thought that memory performance would have been just as good, if not a little better than the older boards, but that was not the case here. Although the performance is very good, we could see this drop the Z97I behind these two older boards in some of our tests that are memory dependent.
Drive performance -
Drive performance is also one of the major subsystems that goes to make up the performance of a motherboard. For our testing we use Sandra and AIDA64 again. We only test with single drives for each type of controller present on the motherboard (unless it is a professional product where we will use RIAD 5 and/or 10). We have also begun using a Thermaltake USB 3.0 dock with another Kingston SCK30/240G 240GB SSD and a Kingston HyperX USB 3.0 Flash drive for our USB 3.0 performance. As a side note, we include the overclocked numbers here to make sure (again) that you are not going to see a major drop in performance due to minor instabilities at high clock speeds.
For drive performance we see the Z97I Plus pull out ahead of the pack in our stock testing by a pretty decent margin. We see this same thing happen with the improved USB 3.0 controller.
For overclocking we find the Z97I Plus in second place for SATA 3.0 performance, but not for USB 3.0 performance. It would seem that the Z97I is a board you will want to go to, if you are looking to run USB 3.0 drives.
Power -
Power efficiency is another of those misnomers that we get caught up in. We hear about idle states and power gates. But what does that mean to you and I? On the surface having power management that reduces idle power sounds great and can be a benefit to someone that leaves their system on for long periods of time (and inactive) but how a system handles power under load and the delta between the two states is often more important than the idle power usage numbers. We use only P3 Kill A Watt instruments for measuring power.
For a small board the Z97I Plus actually pulls a bit of power in the configuration we have setup. You can get the power down, through the use of Asus’ EPU chip and application, but if you are looking to use all of the power available in your CPU you will still get that power draw.
Cooling (Board Level) -
Board level cooling is an important factor in product performance and longevity. Components like the chipset, VRM modules and even capacitors need to be kept relatively cool to prevent failure. As these parts are made of silicon, they have a thermal breakdown threshold; or melting point. At that temperature the actual transistors built into chip will begin to deform and break down. Granted, the threshold is often very high, but you still need to make sure that components stay away from this level of heat for longer product life.
The two heatsinks on the board do a fairly good job of keeping the respective components they cover. We would have liked to see temperatures a little lower, but in reality if you put the Z97I Plus into the right case you will keep these down easily enough.
Audio -
Audio is highly subjective. What we find pleasing may sound “off” to you. That is always going to the problem with testing audio; results will vary too widely depending on the tastes of the listener. However, there are ways of measuring the audio output with an objective ear. There is also the issue of audio causing performance issues in gaming and video playback. The reason this is a potential source of concern is that all onboard audio CODECs (Compression/Decompression) are CPU controlled. This means that while the audio chip controls the audio levels and effects of the audio the actual work is done on the CPU. Usually this will not be a problem with today’s powerful CPUs. Even the lower and consumer level products can handle high-end audio these days. But again there is the chance that a bad design or software will hinder your system and performance. On the other side the limits of board space, cost, etc will also prevent the level of audio quality you can get from an add-in board. We test all audio parts with three media types, Movie (DVD), MP3 Music, and Gaming. These are pushed to our Tec On model 55 Tube Amp to see if we can detect any signal issues in the reproduction.
One of the items that Asus has been working on to differentiate their boards is audio. In the Z97I Plus we found the audio experience to be a little better than most of the “good enough” systems that are out there. It is still not going to win any awards, but for an SFF board the audio is quite good.
Networking -
This one is something that is a requirement anymore. If you have a computer, the chances are good (like 99%) that you are also connected to high-speed internet. With this you need a good and solid LAN chip to make sure that your data flows properly out and back.
A few years ago Asus made the decision to use Intel LAN chips on their motherboards for consistency and also for performance. This decision has given them a fairly solid lead on tuning these chips on their boards to get the most performance out of them.
With the Z97I Plus you not only get a fast Intel LAN controller, but also a Braodcomm 802.11ac wireless adapter. It is quite a combination and the performance you get out of them is impressive.
