Just like NVIDIA nForce4, VIA K8T890 theoretically allows combining PCI Express lanes pretty flexibly so that there could be PCI Express x2 and x4 interfaces. Moreover, the graphics PCI Express x16 bus can be 搒plit?into to PCI Express x8 busses in order to support SLI-like configurations. However, right now NVIDIA drivers do not allow building SLI systems on competitor chipsets that is why you will not find any VIA K8T890 based mainboards with two graphics slots in the market today. However, configurations like that might still be very helpful if you need to install a few graphics cards in your system to ensure multi-display support. So, I wouldn抰 completely deny that one day we may see VIA K8T890 based mainboards with a pair of PCI Express x8 slots for graphics accelerators. I will tell you even more: mainboards like that have already been designed and do exists in the form of engineering samples.
The today抯 mainboards based on the VIA K8T890 North Bridge use VIA VT8237R South Bridge. This chip should be pretty familiar to you because they used it with the previous generation AGP 8x chipsets for Athlon 64 processors. Since this South Bridge is quite old already, its functionality is not as broad as you wish it could be. That is why it is not at all surprising that VIA VT8237R is much scarcer than NVIDIA nForce4 in terms of various interfaces support.
Take for instance the Serial ATA controller built into the VT8237R. It supports only two Serial ATA-150 ports, while the nForce4 supports four of them. Moreover, VIA chipset doesn抰 support NCQ and 3Gbit/s data transfer rate, while nForce4 boasts all these features. Then, even though the VIA chipset allows building RAID 0 or 1 arrays from Serial ATA hard disk drives, the NVIDIA chipset also supports RAID 0+1 and Parallel ATA HDDs.
A similar comparison can be carried out for the chipsets network controllers. NVIDIA nForce4 features Gigabit network controller with ActiveArmor hardware security system. VIA抯 chipset offers only a primitive 10/100Mbit network controller.
As far as the USB 2.0 support is concerned, the features comparison here will also be not in VIA抯 favor: VIA chipset supports only eight USB 2.0 ports, while NVIDIA nForce4 ?ten.
As for the integrated sound solution, VIA K8T890 with its 8-channel AC?7 sound doesn抰 yield to NVIDIA nForce4.
Summing up everything we have just mentioned above, I would like to offer you the following table listing all the major features of both chipsets:
| nForce4 SLI/Ultra | VIA K8T890 |
Architecture | Single-chip | VIA K8T890 North Bridge VIA VT8237R South Bridge |
Bus between the bridges | None | V-Link (1066MB/s) |
HyperTransport | 16bit/1GHz | 16bit/1GHz |
PCI Express busses | 1 x PCI Express x16 3 x PCI Express x4 | 1 x PCI Express x16 3 x PCI Express x4 |
SLI support | Yes 1 x PCI Express x16 = 2 x PCI Express x8 | None* |
Supported PCI devices | 6 | 6 |
USB 2.0 | 10 | 8 |
Serial ATA | 3Gbit/s | 1.5Gbit/s |
NCQ support | Yes | None |
Serial ATA ports | 4 | 2 |
Parallel ATA channels | 2 | 2 |
RAID support | 0, 1, 0+1 | 0, 1 only for Serial ATA |
Ethernet | 1Gbit/s | 10/100 Mbit/s |
Secure Networking Engine | Yes | None |
Sound | 8-channel AC97 | 8-channel AC97 |
* May appear in the future
However, despite not very long features list of the VIA K8T890 chipset, it will still find its market. The thing is that the mainboard makers get this chipset at a considerably lower price than they would pay for the NVIDIA nForce4.
Overclockers may also find VIA K8T890 solution very attractive, because it allows independent clocking of the PCI and PCI Express busses, which is an important advantage. This way, Athlon 64 processors can theoretically overclock much easier on the VIA K8T890 based mainboards. Well, we will not make any final conclusions yet. Now we suggest getting started with the actual VIA K8T890 based mainboard review.