VIA KT266: Final Verdict. MSI K7T266 Pro Mainboard

Well, we are resuming the discussion of VIA KT266 based products and their performance. Our testlab tested the firstmass mainboard on this chipset from MSI - K7T266 Pro. We compared its performance with that of other DDR mass boardsbased on AMD-760 and ALi MAGiK 1.

by Ilya Gavrichenkov
05/10/2001 | 12:00 AM

Some time ago we published the first article devoted to mainboards based on the new Socket A VIA's core logic with DDR SDRAM support, VIA KT266. That time we tested a number of mainboards built on this chipset, but all of them were pre-production samples. Their design was not finalized and they featured temporary, not yet completely optimized BIOS versions. As a result, the performance benchmarks, which were discussed in that article should be regarded as preliminary ones, since they couldn't really characterize the performance of those VIA KT266 based mainboards that we'll see on the shop shelves. As you may remember, that time VIA KT266 didn't reveal any bright results, but we proved that the performance could undoubtedly be improved.


Shortly after that report we got hold of a new mainboard based on the same VIA KT266 chipset. Now we could finally get acquainted with the final version of a VIA KT266 based product represented by MSI K7T266 Pro, which is identical to those that have been freshly delivered to some hardware stores. So, as we have promised, we are returning to VIA KT266 discussion. With the help of a mass mainboard we'll try to figure out whether VIA DDR chipsets for Athlon CPUs will be able to compete successfully with a more expensive AMD-760.

We will not repeat the story of VIA KT266 architecture and other peculiarities and suggest passing over to the real practical issues right away. If you haven't yet read the first article about this chipset, it's worth looking through "VIA KT266 Based Mainboards: the first glance" before you keep on reading.

Closer Look

MSI engineers seem to have done a titanic work to create K7T266 Pro mainboard. For instance, they contrived to develop the first samples of K7T266 Pro prior to VIA's reference boards even. Furthermore, they implemented several unique technologies in their new product, including: USB 2.0, D-LED, PC2PC and IDE RAID. Thus, the engineers' merit can't be underestimated. Now let us see what the specs of the newly-born K7T266 Pro are:

MSI K7T266-Pro
Supported CPUs AMD Athlon/Duron (200/266MHz)
Chipset VIA KT266
FSB Frequencies 100-164MHz
Overclocking Friendly Features Supports CPU Clock Multiplier Setting
Vcore and Vmem adjustment
Memory 3 184-pin DIMM slots for PC1600/PC2100 DDR SDRAM
AGP Slots AGP Pro
Expansion Slots (PCI/ISA/CNR) 5/0/1
USB Ports 6 USB ports
4 USB 2.0 ports (optional)
Integrated Graphics No
Integrated Sound AC'97
Additional Features Promise ATA/100 RAID controller (optional)
D-LED diagnostic system
Integrated USB 2.0 controller (optional)
PC2PC technology (optional)
Form-Factor ATX, 304mm x 235mm

MSI is the first of the great many mainboard manufacturers, who are planning to launch products built on VIA KT266. This core logic is likely to become one of the best-sellers for Socket A systems. And it is not only for its low price. Surely, the price of KT266 is notably lower than that of AMD-760, but the key advantage of the DDR Socket A chipset of VIA remains the rich variety of features. Apart from supporting the new Athlon CPUs with 266MHz bus (other Socket A chipsets of the latest generation boast this feature, too), VIA KT266 sports two more things, which are also possessed by MSI K7T266 Pro.

Firstly, this chipset supports asynchronous memory working mode. It means that if we use a processor with 266MHz bus, K7T266 Pro (as well as any other mainboard built on VIA KT266) is able to work not only with PC2100 DDR SDRAM, but also with 100MHz PC1600 DDR SDRAM, while boards on AMD-760 or ALi MAGiK 1 can't do that. In a similar way, if we take a CPU with 200MHz bus, the memory bus of K7T266 Pro will be able to work at 133MHz, that is to support PC2100 DDR SDRAM. The memory working frequency can be set via BIOS Setup.

Secondly, VIA KT266 is remarkable for its new high-speed V-Link bus, which is designed to connect the two Bridges of the chipset. This bus with doubled bandwidth succeeded the formerly used PCI. Thanks to V-Link, KT266 happily got rid of a potential bottleneck, which may arise when you, say, have to work hard with ATA/100 HDDs.

Getting back to the memory subsystem, we would like to point out that MSI decided not to bundle its K7T266 Pro with DDR DIMM and SDR DIMM slots simultaneously, though this mainboard modification had been considered at first. The matter is that lately the prices for DDR SDRAM have taken a deep plunge in the world market recently and now it isn't expedient to equip a DDR SDRAM mainboard with PC133 and then to upgrade it to DDR SDRAM. That's why K7T266 Pro has only three 184-pin DIMM slots for PC2100/PC1600 DDR SDRAM. It is the highest number of memory slots VIA KT266 can support.

An amusing fact about MSI K7T266 Pro is that the mainboards from the very first supplies and those from the following batches do differ in performance quite tangibly. Physically, these boards differ only by the location of one single resistor, but this tiny element has proven to affect the board performance just miraculously. Keep in mind that on "correct" K7T266 Pro mainboards, like the one tested in our lab, R126 resistor is situated between the South Bridge and the Flash chip. And there should be no neighboring R127 element. As one of MSI engineers tried to explain to us, the location of this resistor tells on the proper setting of the memory timings.

To tell the truth, MSI K7T266 Pro is a unique product not only due to the new chipset used. In this solution MSI implemented practically all the technologies presently developed by the company's R&D department. To start with, it's the D-LED diagnostic system (Diagnostic LED), which was first introduced on MSI boards over a year ago. The system comprises four two-color LEDs located at the rear side of the serial and parallel ports. They depict step-by-step the status of the startup process. So, if any problems arise when the computer is booting, it's pretty easy to identify the trouble-maker by the LEDs combination. The only "but" is that when the mainboard is installed into to the case, the LEDs appear inside, so it is impossible to see them without opening the case. Nonetheless, we admit that D-LED can be utterly helpful in troubleshooting. Besides, MSI took care of those, who would like to watch the indicators, and supplied a D-Bracket - a bracket with diagnostics LEDs to be installed instead of one of the expansion cards.

Then, K7T266 Pro is bundled with an integrated ATA/100 IDE RAID controller. MSI selected Promise PDC20265R microchip - a RAID version of Promise PDC20265 (a chip like that is the "heart" of Promise Ultra100 controller). As for the controller's BIOS, it is a "Lite" version of that of Promise FastTrak100 integrated into the mainboard BIOS. What makes it "Lite" is fact that the RAID controller of K7T266 Pro doesn't support 0+1 level RAID arrays and works only in RAID 0 (mirror) or RAID 1 (stripe) modes. This controller and all the disk array creation operations are managed by means of its own BIOS.

Promise PDC20265R IDE RAID controller

PC2PC is a comparatively young technology for MSI mainboards. It is implemented on K7T266 Pro and yet none of MSI's competitors can offer anything of the kind. This technology lets create a local network by connecting a system based on MSI mainboard, for example K7T266 Pro, to another one with a common USB cable. All the necessary software and a USB cable are shipped in set with K7T266 Pro. The implementation of this innovation is based on an additional USB PC-to-PC File Transfer controller, Genesys Logic GL620USB-A, located on the left side of the board. It allows transferring the data between two USB ports at 8.6Mbit/sec. Note that PC2PC is s supported by only one of the USB ports available on the mainboard.

Genesys Logic GL620USB-A USB PC-to-PC File Transfer controller

The last nice thing about MSI K7T266 Pro, which is worth mentioning, is the fact that this mainboard is formally the first one to support USB 2.0. Indeed, it is supposed to have a USB 2.0 controller by NEC and the board is shipped with a bracket with four USB 2.0 ports. The only matter to stress is that USB 2.0 support is optional. In practice it means that the layout of K7T266 Pro implies the use of a USB 2.0 controller, but you'll find no controller on the currently shipped mainboards. Of course, one may argue that there are no USB 2.0 devices available in the market so far, but we believe that it would be good of MSI to provide the opportunity to transfer the data between the PC and external devices at 480Mbit/sec and to implement USB 2.0 support in full. However, for the time being the users will have to confine themselves to six USB 1.1 ports transferring the data at 12Mbit/sec.

Empty place for USB 2.0 controller

MSI K7T266 Pro is equipped with a BIOS from AMI, therefore if you've got accustomed to the interface of Award BIOS 6.0, you may find the Setup of K7T266 Pro rather poor. Fortunately, it doesn't tell anyhow on the board's configuration options and performance. By the way, BIOS Setup of MSI K7T266 Pro allows both manual and automatic CAS Latency and Memory Interleaving adjustment. For the laziest users BIOS Setup grants High System Performance option, which automatically brings all the system settings at the optimal level in order to reach the highest performance possible.

MSI K7T266 Pro allows overclocking the CPU only via BIOS Setup, since there are no jumpers on this board (except that for clear CMOS command). For this purpose BIOS Setup will let you to increase the FSB frequency up to 164MHz (with an increment of 1MHz), the Vcore up to 1.85V and Vdimm to 2.7V. You can also readjust the unlocked CPU multiplier (if you are keen to learn how to unlock the multiplier of Athlon and Duron CPUs, consult this article).

Speaking of standard characteristics, K7T266 Pro features a pretty ordinary PCB equipped with five PCI slots, one CNR and one AGP Pro slot. In fact, on some mainboards AGP Pro slot can be replaced with a common AGP 4x, as long as the only difference between them is that AGP Pro has additional power supply circuits. Also there is AC'97 sound codec, which implements all the basic sound opportunities, at the expense of the processor resources, though.

To crown it all, let us say a few words about the mainboard design. As a whole, it is pretty well planned but for a couple of slips. First, ATX power supply connector finds itself between Socket A and the ports of the rear case panel. It makes the power supply cable hang over the CPU and hamper its cooling. The second awkward thing lies with the layout itself. Socket A is turned 90 degrees away from its traditional position and is put too close to the right edge of the board. Subsequently, the special cooler fastening "hooks" will appear too close to the case side. So, to install or remove the cooler on K7T266 Pro you'll need to be a sheer contortionist. Besides that, we don't have any other remarks to make about the mainboard layout. Even four gigantic capacitors located next to Socket A won't be a predicament to any popular cooling solutions.

As far as reliability and stability are concerned, K7T266 Pro has proven up to our highest expectations. Perhaps, it's partially thanks to the four huge 470uF capacitors and the improved four-transistor CPU power supply circuit as a whole.

Testbed and Methods

The first thing to stress is that our testbeds have tangibly changed since the times of the last DDR platforms testing. The major innovation is that from this time on we'll test DDR SDRAM systems using PC2100 CL2 instead of the formerly used PC2100 CL2.5. The reason is that now PC2100 with CAS Latency equal to 2 is at last shipped in mass. Apacer became the first company to do that, so for our tests we'll take memory modules manufactured by Apacer.

As you can see on the photo, our memory module is built of Nanya chips. It lets us assume that soon other Nanya customers will start shipping CL2 PC2100 DDR SDRAM modules. By the by, the second biggest DDR SDRAM chips manufacturer, Micron, is not ready yet to offer the bundles for CL2 modules, so it's unlikely that CL2.5 modules will be rapidly replaced with CL2 ones.

Let's turn back to our testbeds. This time, to test DDR Socket A systems, we made use of today's most powerful Socket A CPUs, Athlon 1.33GHz with 266MHz bus. Due to these processors and PC2100 CL2, the testbeds were able to show the best of DDR systems. Thus, as you watch the results shown in this review, don't forget that this time the DDR systems performed at the top of their capabilities and it's very unlikely that further memory subsystem optimization will yield any greater performance gain compared to PC133 systems.

In order to ward off the influence of the graphics subsystem on the results obtained on each of the test platforms, we chose the most powerful graphics accelerator based on NVIDIA GeForce3 chip.

In these tests we aimed at comparing the ultimate performance of different platforms supporting Athlon-C CPUs (working with 266MHz bus). For this purpose we selected systems based on AMD-760, VIA KT266, ALi MAGiK 1 and VIA KT133A chipsets. The first three ones worked with PC2100 DDR memory, and the latter naturally with PC133 SDRAM. We took only mass mainboards, because test samples, which are often used in other test labs, do not always reflect the performance of all products of the kind.

Now we'll cast a glance at the entire band:

  VIA KT266 AMD 760 ALi MAGiK 1 VIA KT133A
CPU AMD Athlon 1.33GHz (266MHz bus)
Mainboard MSI K7T266 Pro Gigabyte GA-7DX ASUS A7A266 ABIT KT7A
Memory 256MB Apacer PC2100 CL2 DDR SDRAM 256MB PC133 CL2 SDRAM
Graphics card Gigabyte GV-GF3000DF (NVIDIA GeForce3)

We tested in office and gaming applications using Windows 98 SE, while for professional OpenGL applications we restarted the systems in Windows 2000 Professional SP1.


In the end of our previous article devoted to KT266 the synthetic benchmarks showed that mainboards based on this chipset work slowly because of their ill-optimized BIOS. So, it's reasonable to start this review with the results of the same synthetic benchmarks, which confirm that now we have a mainboard with well-optimized BIOS.

Well, in comparison with the previous results we can see a notable progress. Now VIA KT266 prides itself on the same read speed as AMD-760, though its latency and write speed are slightly worse. There is nothing strange about it. The memory controller of VIA KT266 is asynchronous (unlike that of AMD-760), hereat it is forced to insert extra wait states to synchronize the signals.

Here follow the results of SiSoft Sandra 2001:

Once again we can see that there has been a considerable progress made since our last VIA KT266 investigation. VIA KT266 catches up with AMD-760. VIA KT133A in its turn shows the lowest memory bus bandwidth, because now PC133 and DDR systems have nearly equal latencies thanks to CL2 memory used in both cases, and DDR SDRAM is generally known to be faster.

These results allow us to state that now VIA KT266 faces no artificial obstacles limiting its performance. Let's find out how this fact has affected the board's performance in real applications.

We were perplexed to see the results of Business Winstone 2001: they say that the VIA KT133A platform with PC133 SDRAM has somehow outpaced the DDR systems based on AMD-760 and ALi MAGiK 1. Surprising at is might seem, this phenomenon is quite easy to explain. To assess the performance, this test measures the time needed for various operations in typical office applications. Accordingly, the final result is strongly influenced by the disk subsystem performance. Slower ATA controllers of AMD-760 and ALi MAGiK 1 based mainboards result this way in lower performance. Don't miss the fact that in spite of VIA 686B South Bridge used on the tested AMD-760 based mainboard, its disk subsystem works slower anyway than the disk subsystem of VIA KT133A based mainboard, where the same South Bridge is used. Most probably, it's the matter of VIA Bus Mastering drivers, which seem to "disapprove" of the alliance between AMD-761 and VIA 686B chips.

When we turn to memory-demanding content creation applications, everything goes the right way. DDR chipsets break ahead leaving their PC133 rivals far behind, while VIA KT266 is feeble 1% slower than AMD-760.

Now 3D games come in the spotlight. Quake3 traditionally requires a lot from both memory bus bandwidth and memory latency. It reveals relatively close performances of AMD-760 and VIA KT266. Meanwhile, AMD-760 takes the advantage of its a little bit lower memory latency to rush forward. ALi MAGiK 1 has upset us with the poorest result of all - it lags even behind VIA KT133A with PC133 SDRAM.

Higher resolutions don't lead to any decisive twist. However, the gap between AMD-760 and other competitors gets larger reaching 2.5% compared with the defeated VIA KT266.

Unreal Tournament makes a welcome change for VIA KT133A. In this test it overcomes even the awesome VIA KT266. Nevertheless, AMD-760 firmly retains the leadership. As for ALi MAGiK 1, it leaves very much to be desired.

The same trend exists at higher resolutions.

In this game we can see a similar situation. Like in Quake3, AMD-760 outstrips VIA KT266 (this time by 2%).

At higher resolutions the graphics subsystem becomes a stumbling stone, so the figures get slightly leveled out. No other quality changes are observed.

The diagram brings nothing unexpected. The only thing to mention is the pleasantly high performance of VIA KT133A with PC133 SDRAM. As we have already seen, despite CL2 memory used in DDR systems, in real applications the performance of PC133 SDRAM and DDR SDRAM platforms differs no more than by 5%. It makes for the fact that at present typical applications are yet unable to profit from the enlarged bandwidth of DDR SDRAM.

In all the games we could trace the same logic. AMD-760 runs first, then arrive VIA KT266 and VIA KT133A followed by the lagging behind ALi MAGiK 1.

Attempting to find out how DDR platforms will feel in the games to come, we tried our systems in 3DMark2001:

We were not surprised to see practically the same scene. The main idea about future 3D games is that the graphics accelerator gets more and more advanced, enhanced with new functions.

As a rule, professional OpenGL applications are most sensitive to the memory bus bandwidth since they need huge memory arrays. Remembering this peculiarity, we paid special attention to SPECviewperf benchmark.

Professional applications have turned out a fruitful field for DDR SDRAM, where it can make the most of its huge memory bus bandwidth and improve the results obtained. Even the former laggard, ALi MAGiK 1, has finally managed to jump ahead of VIA KT133A with PC133 SDRAM. As for VIA KT266 and AMD-760, in this test they keep abreast.


AMD-760 is still the fastest Socket A core logic. Thanks to its synchronous memory controller with SuperBypass support, AMD-760 is a definite leader in memory matters. On the other hand, this chipset is rather pricy and requires six-layer mainboards. Hence, we are unlikely to meet any cheap products based on this chipset. To say more, AMD itself isn't eager to manufacture AMD-760 in large quantities, so new mainboards based on AMD-760 don't tend to become widely spread. Nevertheless, this chipset is well suited for building high-performance DDR systems.

VIA KT266 is nonetheless an ample substitute for AMD-760. It loses negligible 1-2% to AMD-760 in performance and is perfect for cheap and massive Socket A mainboards with DDR SDRAM. Besides, this core logic has broader opportunities than AMD-760. Its most important advantages are the asynchronously working memory and internal V-Link bus that help to avoid a potential bottleneck threatening Bridge-to-Bridge data transfer. Recapping it all, we can recommend mainboards with VIA KT266 as a good choice to assemble both high-performance and mainstream systems.

We are vexed at the failure of ALi MAGiK 1, though ALi asserts that its performance should grow if used with CL2 memory. Our test charts must have shattered the dreams of all the chipset admirers. In most cases ALi MAGiK 1 looks even worse than VIA KT133A with PC133 SDRAM.

The PC133 chipset, VIA KT133A, can be proud of unpredictably cool performance. Regardless of its two times slower system memory, VIA KT133A is only 5-10% not so fast as DDR chipsets. So, while DDR SDRAM and corresponding mainboards stay more expensive than PC133 SDRAM chips and mainboards, VIA KT133A goes on opposing Socket A chipsets with DDR SDRAM support.

The key figure of this review, MSI K7T266 Pro, has produced a most favorable impression on our team. The first mainboard based on VIA KT266 shows remarkable performance and stability. Strengthened with a number of unique features (like the PC2PC technology), these characteristics are sure to make MSI K7T266 Pro one of the best Socket A mainboards with DDR SDRAM support.