We carried out our tests on a testbed that included the following components:
- Mainboard: Asus Sabertooth 990FX rev.1.01 (BIOS version 0810);
- AMD FX-8150 CPU (3.6 GHz, Zambezi (Bulldozer), AM3+);
- 2 x 2048 MB DDR3 SDRAM Patriot Extreme Performance Viper II Sector 5 Series PC3-16000, PVV34G2000LLKB (2000 MHz, 8-8-8-24 timings, 1.65 V voltage);
- MSI N570GTX-M2D12D5/OC graphics card (Nvidia GeForce GTX 570, GF110, 40 nm, 786/4200 MHz, 320-bit GDDR5 1280 MB);
- Kingston SSD Now V+ Series (SNVP325-S2, 128 GB);
- Scythe Mugen 2 Revision B (SCMG-2100) CPU cooler and an additional 80x80 mm fan for cooling of the area around the CPU socket during overclocking experiments;
- ARCTIC MX-2 thermal interface;
- CoolerMaster RealPower M850 PSU (RS-850-ESBA);
- Open testbed built using Antec Skeleton system case.
We used Microsoft Windows 7 Ultimate SP1 64 bit (Microsoft Windows, Version 6.1, Build 7601: Service Pack 1) operating system, Intel Chipset Software Installation Utility version 22.214.171.1240, Nvidia GeForce Driver 280.26 graphics card driver.
Operational and Overclocking Specifics
We didn’t experience any difficulties assembling the system on Asus Sabertooth 990FX mainboard. However, we have a few things we would like to say about the process. First of all, it is really interesting to find out when we will finally get a Socket AM3+ mainboard that will work with a Socket AM3+ processor right from the start. So far we have to install an old Socket AM3 CPU and update the BIOS before we can work with the new processor. The second thing I would like to mention has to do with power-saving technologies, which are partially disabled by default. As we will see later on, in our Power Consumption chapter, enabling them could have made the system much more energy-efficient.
In our previous review we checked out the “OC Genie II” function for immediate overclocking on Micro-Star mainboards, but for some reason e left out a similar option available on Asus boards. As you remember, when you press the OC Genie button on MSI 990FXA-GD80 or select the corresponding function in the BIOS, the base clock frequency increases to 225 MHz, the memory frequency multiplier drops, the timings are set to more aggressive values, the voltages increase. As a result, the processor overclocks to 4 GHz and the memory frequency drops to 900 MHz. A serious problem with this primitive overclocking is that all power-saving technologies get disabled. Therefore, even in idle mode the CPU will continue running at very high frequency and voltage.
When you select the OC Tuner option in the BIOS of Asus Sabertooth 990FX, the base clock frequency increases to 230 MHz, but at the same time the memory frequency increases, too. Overall, the automatic overclocking on Asus mainboard produced better results than on MSI, only the memory timings could have been set lower, because the board is quite capable of taking them from the modules SPD.
Moreover, power-saving technologies stay up and running and lower the processor clock frequency multiplier and Vcore in idle mode, so we can totally recommend this overclocking as a starting point for commencing users.
However, everyone knows that automatic overclocking tools may one be useful when you do not have time or desire to search for optimal parameters, but they can never compare with the efficiency of manual overclocking, when every little adjustment has been carefully tested and confirmed. In this respect, Asus Sabertooth 990FX didn’t yield even a tiny bit to Asus Crosshair V Formula and confidently overclocked our processor and memory to the maximum possible frequencies in the provided conditions. Since there is HPC Mode support in the BIOS, the processor frequency doesn’t drop under heavy load.
We always overclock mainboards in such a way that they could be used permanently in this mode. We do not try to make our life easier by disabling any of the mainboard features, such as onboard controllers, for example. We also try to keep the CPU's power-saving features up and running normally. Asus Sabertooth 990FX was overclocked in this manner, too. When idle, it lowered the CPU voltage and frequency multiplier to save power.
Overall everything looks good, only one thing left a not very good aftertaste: periodically increasing noise during long-lasting stability tests in overclocked mode. We always install an additional 80x80 mm fan for cooling the area around the processor socket during our overclocking experiments. Its nominal rotation speed is about 2300 RPM, but we usually do not need it working that fast. A slight airflow from this fan is usually enough to significantly lower the temperature of all heatsinks around the processor, so we normally slow it down to 75% or even 50%. The power consumption and heat dissipation of the new AMD platform turned out so high that we had to use this fan even in the nominal mode with a “Silent” preset. However, in overclocked mode during long stability tests the fan would occasionally speed up to its maximum, which created certain acoustic discomfort.
However, it would be totally unfair to consider more aggressive approach to fan rotation speed adjustment a drawback. First, it is the mainboard’s job to maintain adequately low temperature of its components to ensure that they last. Second, we have at our disposal a flexible tool for adjusting temperatures, voltages and fan rotation speeds – Thermal Radar technology, which requires installing a special program with the same name.
This program allows monitoring the current voltages, temperatures and fan speeds with the help of numerous diodes. By default the fan speeds depend on the CPU temperature that is why as its temperature increases, the fans speed up to their maximum. However, Thermal Radar program allows us to change the fan rotation speed adjustment parameters. For example, we can limit the maximum rotation speed threshold or make the adjustment dependent on the readings from another thermal diode.