The Board - A Closer Look

Our usual first item to look at, of course, is the BIOS chip itself, which in this instance, is supplied by cFeon. Nestled securely in a socket that makes user replacement fairly simple, the TA990FXE shows that user experience is first and foremost with Biostar, as if a user is to ever corrupt the BIOS past available recovery options, there's no need to tear down the system and RMA the entire board. There is also a dual-digit POST display located below the SATA ports that will convert to displaying CPU temperatures once the POST process has completed. Once the BIOS has booted the TA990FXE up, the real brain of the board, the STMicro L6717A VRM controller, is in full operation. Providing control for 4+1 phases, the L6717A features an I2C interface, so should be software controllable as well, provided that the Biostar tools are written to take advantage of it.


As we mentioned before, there are both ON/OFF and RESET switches at the bottom board edge, great for testing the board when you first get it, or if you plan to do some extreme cooling and benchmarking. Of course, when you press that ON/OFF switch, you'll notice the LEDs in the second image above flicker to life. Connected to the STMicro L6717A, they indicate phase loading, with one light for each phase. The intensity of the light they produce also indicates how much load the phase is under, a useful tool when clocking your chips as well as providing a bit of "bling".


The TA990FXE features a standard VRM design that was designed by STMicro to work in conjunction with the L6717A controller, which is organized in a standard Hi/Lo triplet, and dual input drivers, seen flanking the phases on the far right side of the image above. The single-phase DIMM VRM features a very similar design, which we found to be fairly effective once we began our overclock testing. The NB VRM is also a single phase, and as you can see in the image above, there is also a Molex connector nearby, to supply additional current to the PCIe lanes when they are fully populated. This is becoming more common in high-end products due to the high power draw of some of high-end VGAs on the market today, so this is something we are very happy to see on a product claiming to be "Extreme".


The Realtek RTM880N clock generator in the first image above is used to source bus clocks, and is one we have been seeing quite often as of late, both on AM3+ and FM1 products. It is a capable chip, but it does seem to have a bit of a problem scaling the HTT to the uttermost extremes with some CPUs. On a whole, it provides quite stable clocks that allow consistent long-term overclocks to remain fully stable.
For Super I/O functionality, we find an ITE IT8728F, a part used quite often on other products. As is usual, this chip is responsible for fan control and data monitoring. The VIA VTE315N drives the FireWire port found on the rear I/O, as well as the internal FireWire port header found near the board's bottom edge.


The included Realtek ALC892 HD codec supports 7.1+2 audio, and meets Microsoft's WLP3.x audio requirements. Using DACs that output a 97 dB SNR, and ADCs with a 90 dB SNR, it supports 44.1k/48k/96k/192 kHz sampling at 16-, 20- and 24-bit, including full support for HD audio formats featuring Content Protection, if supporting software is used. It is also DirectSound 3D compatible, so no area of usage or functionality is overlooked.
Biostar has sourced the LAN controller for the TA990FXE from Atheros, a widely known name, but the AR8151B is not a part we've run across lately very often, which features low-power operation and runs along the PCIe bus.


For USB 3.0 support, we find two matching Asmedia AS1042 PCIe controllers, with one under the DIMM slots, supporting the internal port we find nearby the controller itself, while the second is hidden between the VRM heatsink, and the rear I/O assembly. While these controllers are not as familiar as the NEC/Renesas controller, which is far more common, we have found Asmedia controllers to be used on many recently-released Biostar products, as well as a few from other OEMs, and this chip has proven itself as a fantastic solution on the other products we've looked at.


For cooling, Biostar has equipped the TA990FXE with several aluminum passive heatsinks with red-anodized vanity plates, which you can see in the pictures above. The Northbridge heatsink is fairly beefy, and the same profile design is carried over to the VRM heatsink as well, with a single heatpipe connecting the two together. The Southbridge heatsink, however, is quite small, providing several millimeters of clearance for installed expansion cards, yet through our testing, proved more than adequate. Upon removal of the VRM/NB heatsink assembly, we noticed near perfect contact from end to end, such that we do hope to see the same thermal interface pad used on other products. You can see clear impressions made by the VRM's components, ensuring that every critical component gets the cooling it needs, extremely vital when it comes to overclocking. The northbridge and southbridge heatsinks use a very familiar gummy pink thermal interface material that pulled away from both the cooler and the northbridge itself when we removed the cooler. This material is such that we recommend that the northbridge cooling is NOT removed under any circumstances, as it was quite difficult to clean off of the chipsets and coolers.


In the above picture you can clearly see the new AMD990FX chipset, and as you can tell, it's very similar to the AMD970 chipset featured in the M5A97 EVO review. The AMD SB950 southbridge seen in the second image above is nearly exactly the same size as the 990FX northbridge, but it's obvious which is which upon close inspection.