| |
 |
|
Date |
: Dec 24th, 2001 |
| Category |
: Motherboards |
| Manufacturer |
: AOpen |
| Author |
: Jin-Wei Tioh |
|
Click To Enlarge |
|
The VT8366 North Bridge, the core of the VIA KT266 chipset, sits between the CPU socket and the AGP slot, roughly an inch from each. It provides all the major features of the chipset, namely DDR, 100/133MHz FSB as well as AGP 2x/4x support. While a new chipset is obvious, what is not so obvious is the introduction of V-Link, VIA’s answer to Intel’s two year old IHA (Intel Hub Architecture). Previously, most north and south bridges were interconnected via the 33MHz PCI bus, offering a peak bandwidth of 133MB/s to be shared between the two bridges as well as all other PCI devices (eg. ATA controller, NIC, sound card). V-Link doubles the signalling rate to 66MHz, thereby doubling the peak bandwidth offered (266MB/s) to accommodate modern high-bandwidth consumption interfaces such as USB 2.0 and FireWire. AOpen opted to forgo their previous passive cooling solutions in favor of a sharp looking, silver AOpen chipset cooler, making the addition of a fan or Blue Orb
unnecessary.
|
The AK77 Plus comes equipped with a universal AGP slot, which means that it is not keyed specifically for AGP 2x or AGP 4x cards. Additionally, AOpen has added a locking mechanism at the end of slot which helps secure the AGP card in place. It is basically a small plastic clip, working similarly to that of a DIMM slot by clipping onto the small tab on the AGP card. While it would take quite an amount of force to unseat the AGP card (an amount that would likely have damaged other components more severely), it is a small, but welcome feature.
Like most motherboards on the market, the AK77 Plus sports 3 DIMM slots for a maximum memory capacity of 3GB. At any FSB range, you have the option of running your RAM at either 3X or 4X PCI clock. This makes for an interesting point for those who want to run a 133MHz FSB CPU, whilst maintaining their older PC1600 DDR SDRAM.
The VIA VT8233 South Bridge basically boasts support for Ultra-ATA 100 and 6 USB ports, on par with all other chipsets. Some interesting features include support for 6-channel AC'97 sound, and the VT8233's integrated 10/100 BaseT Ethernet and 1/10 Home PNA controller. While AOpen chose not to implement these more advanced features, it is certainly interesting to see the move towards everything being integrated. For expansion slots, AOpen chose to go with the more OEM oriented 1/5/0/1 (AGP/PCI/ISA/AMR) configuration, something which ASUS also decided to do on their A7V266. As mentioned earlier, all the slots on the AK77 Plus are capable of accommodating full-length cards.
The AK77 Plus features an impressive capacitor count; 3 3300uF, 12 2200uF, 2 1200uF, and an assortment of smaller capacitors. 6 voltage regulators with large honking heatsinks sit adjacent to the CPU socket. As with both the AK73 Pro (A) and AX3S Plus, AOpen employs one of their techniques in achieving stability - better distribution of capacitance. They utilize a greater number of lower capacitance low ESR (equivalent series resistance) capacitors. Hence, while the total capacitance may be the same, it is distributed more evenly throughout the motherboard.
To further enhance stability, the AK77 Plus was designed with the "Frequency Isolation Wall". AOpen attempts to separate the motherboard into regions, where each region is running at similar local frequencies. This serves to minimize signal interference via cross talk which is an unavoidable occurence in electronic circuits. They also took the pains in calculating the trace lengths and routing to ensure that traces operating at the similar clocks have equivalent lengths, minimizing clock skew.
Click To Enlarge |
|
In the overclocking department, the AK77 Plus features a jumper for FSB range selection (ie. either 100-132MHz, or >= 133MHz), adjustable in 1MHz increments via the BIOS. The FSB clock generator used is capable of a whooping, no insane 248MHz! CPU core voltage is fully jumperless, allowing adjustments from 1.1V to 1.85V in 0.25V increments. CPU multiplier selection is done via DIP switches. However, VIO and DIMM voltage adjustments are absent. We'll find out how the absence of these two features affect the AK77 Plus' overclockability. The CPU fan header held up well when paired with a black-label Delta fan. |
|
|
