VIA Socket 754/939/940 North Bridges

VIA's AMD chipset offerings are pretty similar in terms of features to their Intel offerings. Let's start with the discreet solutions again.

Platform Summary - Discrete Socket 754/939/940 Chipsets
K8T800 Pro K8T890 K8T890 Pro
Processor Bus 1 GHz HyperTransport (1 GHz 16-bit Full Duplex) 1 GHz HyperTransport (1 GHz 16-bit Full Duplex) 1 GHz HyperTransport (1 GHz 16-bit Full Duplex)
Memory Support Single- or Dual-channel DDR-1 266/333/400 Single- or Dual-channel DDR-1 266/333/400 Single- or Dual-channel DDR-1 266/333/400
Graphics Support AGP 4X/8X PCI Express VIA DualGFX Express (Dual PCI Express)
Chip Interconnect 8X V-Link Ultra V-Link Ultra V-Link
South Bridge VT8237 VT8237/VT8251 VT8251
Sampling Already Available Now Now (Sept. '04)

As you can see, things match up almost exactly with the Intel platform chipsets. Of course they use a HyperTransport bus to interface with the processor as opposed to the quad-pumped bus of Intel designs, and they do not have a memory controller as that is taken care of by the AMD processors. Other than that, though, we see similar features with the difference being in the graphics and South Bridge support. VIA does not have plans for an AMD chipset with both AGP and PCIe interfaces, but we still have the option of a dual PCI Express graphics solution with the K8T890 Pro. Again, the high end model requires the use of the more advanced VT8251 South Bridge, but those are the only major differences. Remember that DDR2 memory support is not an option for AMD systems right now, as that is determined by the CPU's memory controller.

Platform Summary - Integrated Socket 754/939/940 Chipsets
K8M800 K8M890
Processor Bus 800 MHz HyperTransport (800 MHz 16-bit Full Duplex) 1 GHz HyperTransport (1 GHz 16-bit Full Duplex)
Memory Support Single- or Dual-channel DDR-1 266/333/400 Single- or Dual-channel DDR-1 266/333/400
Internal Graphics 200 MHz UniChrome Pro 250 MHz DeltaChrome IGP (DX9)
External Graphics AGP 4X/8X PCI Express
Chip Interconnect 8X V-Link Ultra V-Link
South Bridge VT8237 VT8251
Sampling Already Available Oct. '04

On the integrated graphics chipsets, we have only two options. The currently shipping K8M800 uses the older UniChrome Pro IGP with the option of an AGP add-in card, while the K8M890 includes the DeltaChrome IGP as well as a PCI Express graphics slot. The K8M890 also supports a faster 1 GHz HyperTransport bus and the Ultra V-Link. As there are currently no high performance IGP chipsets for Athlon 64/Opteron, VIA has the potential to gain some market share, especially in the low-cost market. Of course, our recent look at ATI's chipset plans show that this is not going to be the case for much longer. Depending on pricing, though, VIA may still provide a reasonable alternative to other IGP solutions.

VIA Chipsets for Socket 478/775 South Bridges, etc.


View All Comments

  • Jii - Monday, January 17, 2005 - link

    VT8251 has support for PCI-e, but not for 10/100/1000 LAN?

    There must be an error on the southbridge chip comparison table - at least I hope so.
  • quanta - Wednesday, November 03, 2004 - link

    #7, it is possible count PCIE device as PCI. After all, PCIE software is supposed to be software compatible with PCI. Reply
  • Fluff - Wednesday, October 20, 2004 - link

    Give us RAID-5 dammit. Reply
  • Regs - Wednesday, October 20, 2004 - link

    I believe the VT8251 has 7 because of SLI. 2 slots that could be programmed to 8x PCI-Express. The remaining 5 are normal. Reply
  • JarredWalton - Tuesday, October 19, 2004 - link

    Pete, I must admit that I sort of wondered the same thing. With PCIe being the future and most people currently using at most three PCI boards, adding yet another PCI slot seems pointless. It may have something to do with the integrated PCI devices counting against that total. Just a guess. I doubt that we'll actually see any 7 slot PCI boards ship, regardless. Reply
  • Pete84 - Monday, October 18, 2004 - link

    Any idea why the VT8251 has 7 PCI slot support? What board would use so many? With even three or four add in cars, the bandwidth would be so low it wouldn't be funny . . . so why?? Reply
  • TrogdorJW - Monday, October 18, 2004 - link

    #4 - I mention the overclocking not because some of the K8T800 Pro motherboards can't overclock - i.e. the Asus - but because we have had a few more issues getting reasonable overclocks out of the VIA chipset boards. Anyway, the NF3 250Gb still comes with better Gigabit Ethernet, as well as a hardware firewall. All things being equal, I still prefer that chipset. It's close, so if the K8T800 Pro comes with a less expensive motherboard (from a brand you trust), more power to you. We won't know for sure until boards ship, but we like to hope that the PCI/AGP lock will now function properly on all future VIA chipsets. :)

    5 - Typical time from sampling to first availability tends to be around 3 months, I would say. If the new chips are pin compatible, it can sometimes be less. With the new chipsets offering PCI Express, I would guess 3 or 4 months is more likely from most manufacturers, but I'm sure we'll see some before the end of 2004.
  • Noli - Sunday, October 17, 2004 - link

    When it says that the k8t890 and k8t890 pro are sampling now, does that mean anyone can work out when we will actually be able to buy motherboards with these chipsets on them? Reply
  • thebluesgnr - Sunday, October 17, 2004 - link

    "Performance between the K8T800 Pro and Nforce3 250 Ultra is very close, but NVIDIA offers additional features and improved overclocking."

    The overclocking potential for both are pretty much the same. On AT's motherboard roundup for socket 939 the ASUS A8V overclocked just as good as the best nForce3 Ultra mobo. And although VIA K8T800 Pro had problems with its PCI/AGP lock at first, the issues are all fixed now while some nVidia boards are still having PCI/AGP lock issues.
  • xsilver - Saturday, October 16, 2004 - link

    what hasn't been mentioned is if the pci/agp lock will be fully functional on the k8t890pro or have I been under a rock for a while?

    Still I can't see why you would want to buy this over a nforce 4 (NOT a fanboy, they just have such a good track record)
    If the k8t890pro hits with 2x PCI express lanes nvidia surely much hit back with just as much if not more?

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