VIA KT series
The VIA KT series (VIA KTxxx (A)) from VIA Technologies is a family of chipsets for PC motherboards . These chipsets are suitable for processors from Advanced Micro Devices with EV6 bus protocol .
Naming
Originally the KT series was supposed to be called KZ , but since this abbreviation turned out to be pre-loaded, the name KT was chosen. The renaming was not a problem, as the name was not applied to the chip itself.
Up to the KT333, the chipset name is prefixed with the name Apollo in the tradition of the older VIA Apollo series . Since this name went under in public, VIA officially omitted it from the KT400 onwards. The KX133 does not actually fit into the naming scheme, but due to its similarity to the KT133 it is not to be seen as an independent chipset or even chipset family.
The suffix A for the chipsets indicates that they are only a marginally revised variant of the original version. Only minor changes have been made to these Northbridges .
Southbridges
KTxxx (A) is just the marketing name for the northbridge of the chipset. Since all VIA Southbridges from VT8231 can be combined with all VIA Northbridges from KT266 or P4X266 using V-Link , it is not possible to determine exactly which Northbridge is combined with which Southbridge . Due to the development over time and the desired features, the mainboard manufacturers still recommend certain combinations:
- KX133 + 82C686A
- KT133 + 82C686A
- KT133A + 82C686B
- KT266 + VT8231
- KT266A + VT8233
- KT333 + VT8235
- KT400 + VT8235
- KT400A + VT8237
- KT600 + VT8237
- KT880 + VT8237
Models
KX133
The KX133 is the first chipset from another manufacturer for the EV6 bus protocol used by AMD in the Athlon . Up to the KX133, only AMD offered a suitable chipset with the AMD 750 (Irongate). However, this was limited to PC-100, so the KX133 made PC-133 possible for AMD processors for the first time. He also marked the beginning support of AMD by other manufacturers in their efforts to establish a second platform alongside Intel.
KT133 (A)
The KT133 is the successor of KX133 and the first chipset for AMD's Socket A . Like the latter, it supports PC-133 memory, but is otherwise very similar to it. However, a change in the specifications of the bus protocol for the socket A processors required a change to the chipset. Strictly speaking, the KT133 is just a new revision of the KX133.
The KT133A expands the KT133 to support an FSB of 133 MHz. Otherwise both chips are identical. Both chipsets support a maximum of 256 Mbit memory chips.
KT266 (A)
The KT266 is the first chipset alongside the AMD 760 to support DDR-SDRAM of the types PC-1600 / DDR-200 and PC-2100 / DDR-266. In addition, this Northbridge debuts for the first time the new type of connection to the Southbridge, called V-Link , which enables a significantly higher data transfer rate and frees the PCI bus from communication within the chipset.
However, the KT266 showed great weaknesses in the memory speed , so that the KT266A was necessary as a revised version and the expectations of the chipset could now be met.
KT333
With the introduction of the new AMD Athlon XP processors with an FSB of 166 MHz, a new chipset was required that officially supports this speed. This KT333 also supports PC-2700 / DDR-333 as memory. The original KT333 in the revisions CD and CE was the last chipset from VIA for socket A with support for AGP 1x / 2x graphics cards. The KT333 in revision CF was a relabeled KT400 (but without AGP 8x capability) and could be destroyed when using AGP 1x / 2x cards.
KT400 (A)
The KT400 brought contrary to expectations, no increase in the FSB or memory interface but was only improved in detail KT333: AGP 8x and 8 × V-Link were introduced. Support for PC-3200 was originally planned for this chipset, but for unknown reasons (presumably design error) it only worked with an FSB of 133 MHz (and only very slowly there). Only the KT400A increased the memory speed to the PC-3200 / DDR-400; that was the only difference.
KT600
The KT600 brought the increase in FSB to 200 MHz that was already expected in the KT400 and KT400A. The direct competitor of the KT600 was the nForce2 Ultra 400 from NVIDIA, to which VIA lost massive market share because it offered a higher speed, albeit mostly only marginally.
KT880
With the KT880 , VIA brought a northbridge with dual-channel memory controller onto the market for the first time. Otherwise it does not differ from the KT600. However, the KT880 came on the market much too late and was hardly widely used because the AMD K8 processors had established themselves in the meantime.
Model overview
| Furnishing | Northbridge name |
Front side bus |
Storage controller | Max. Memory size: |
AGP compatibility: |
Southbridge connection: |
|---|---|---|---|---|---|---|
| KX133 | VT8371 | 100 MHz EV6 | Single-channel SDR-SDRAM PC-133 | 2.0 GB | 2.0 (1 ×, 2 ×, 4 ×) | PCI |
| KT133 | VT8363 | 100 MHz EV6 | Single-channel SDR-SDRAM PC-133 | 1.5 GB | 2.0 (1 ×, 2 ×, 4 ×) | PCI |
| KT133A | VT8363A | 133 MHz EV6 | Single-channel SDR-SDRAM PC-133 | 1.5 GB | 2.0 (1 ×, 2 ×, 4 ×) | PCI |
| KT266 | VT8366 | 133 MHz EV6 | Single-channel DDR-SDRAM PC-2100 | 2.0 (1 ×, 2 ×, 4 ×) | 4 × V-Link | |
| KT266A | VT8366A | 133 MHz EV6 | Single-channel DDR-SDRAM PC-2100 | 2.0 (1 ×, 2 ×, 4 ×) | 4 × V-Link | |
| KT333 | VT8367 | 166 MHz EV6 | Single-channel DDR-SDRAM PC-2700 | 2.0 (1 ×, 2 ×, 4 ×) | 4 × V-Link | |
| KT333CF | 3.0 (4 ×) | |||||
| KT400 | VT8368 | 166 MHz EV6 | Single-channel DDR-SDRAM PC-2700 | 3.0 (4 ×, 8 ×) | 8 × V-Link | |
| KT400A | VT8377A | 166 MHz EV6 | Single-channel DDR-SDRAM PC-3200 | 3.0 (4 ×, 8 ×) | 8 × V-Link | |
| KT600 | VT8377 | 200 MHz EV6 | Single-channel DDR-SDRAM PC-3200 | 3.0 (4 ×, 8 ×) | 8 × V-Link | |
| KT880 | VT8379 | 200 MHz EV6 | Dual-channel DDR-SDRAM PC-3200 | 3.0 (4 ×, 8 ×) | 8 × V-Link |