Well, the first group of Socket A mainboards for AMD CPUs turned out to be developed for OEM. Today we are going to offer you the third review of a Socket A mainboard. This time it will be AOpen MK33, which is also aimed at OEM, like all the previous pieces tested. Of course, this fact tells noticeably on the products functional peculiarities, which appear very limited. Most of our readers fond of CPU overclocking look forward to getting a wider choice of Socket platforms for AMD CPUs. That's why we advise you to regard this review just a cause for thinking about waiting a bit more…

Speaking about AOpen products in general, we should stress once again that this company focuses on the stability of its products in the first place. Like Gigabyte mainboards, products from AOpen have hardly aroused any reproach from this point of view. The previous Slot A mainboard for AMD CPUs, AK72, showed really high performance and stability in our testlab. Now let's find out how the things with a new mainboard on VIA KT133 chipset stand.

Specification

• CPU
  • Supports Socket A AMD Athlon and AMD Duron CPUs with integrated on-die L2 cache
• Chipset
  • VIA Apollo KT133 (VT8363+VT82C686A)
• System memory
  • 3 168-pin DIMM slots of 3.3V supporting up to 1.5GB PC100/PC133 SDRAM and VC100/VC133 VCM
• AGP
  • AGP slot supporting 4x mode
• Slots
  • 3 PCI slots compliant with PCI 2.2 specification
• Integrated sound
  • Software AC'97 sound controller
• I/O ports
  • 1 FDD port, 2 serial and 1 parallel ports, ports for PS/2 mouse and keyboard
  • Joystick jack, microphone in, line in and out
  • 2 built-in USB ports and two additional USB ports
  • IrDA TX/RX connector
• Integrated UltraDMA/66 IDE controller
  • 2 UltraDMA/66 Bus Master IDE channels (supporting up to 4 ATAPI devices)
• BIOS
  • 2Mbit Flash EEPROM
  • Award BIOS
• Other
  • Wake on modem, mouse, keyboard, LAN, USB-devices and timer
  • Hardware monitoring
  • 2 fan connectors
  • Suspend-to-RAM support
• Dimensions
  • MicroATX form-factor, 24.4x24.4cm

The mainboard is shipped in a beautiful multicolor box. The package includes UltraDMA/66 and FDD cables, a poster with brief installation hints and a CD-disk. The CD-disk can't offer much: besides the conventional drivers and utilities, there is only a full user's manual there. AOpen followed in the footsteps of some other mainboard manufacturers, which prefer to provide a full user's manual in a pdf-file rather than in a printed booklet. Of course, this is not the best thing if you assemble your first PC, but it is quite OK for the OEMs. Unfortunately, AOpen hasn't yet followed the example of those mainboard manufacturers, which accompany their boards with commercial software. But again for MicroATX AOpen MK133 aimed at OEM it is not that important.

Closer Look

Well, as we have already said AOpen MK33 is based on VIA Apollo KT133 chipset. This core logic is none other but KX133 chipset adapted for use in Socket A mainboards. KT133 as well as KX133 supports EV6 system bus, PC133 SDRAM and AGP 4x that's why there are hardly any visible differences between these two chipsets except the supported processor form-factor. AOpen can boast two mainboards on KT133 in its product range: besides our today's hero, MK33, there is one more Socket A mainboard - AK33. This is an ATX mainboard with the features a bit more attractive for individual users. However, it isn't available yet that's why we have to satisfy our curiosity with MK33.

Unfortunately, we have to point out that AMD wouldn't now recommend using AOpen MK33 with its Athlon and Duron CPUs. However, our tests didn't reveal any problems. Both AMD Duron and Thunderbird worked fine in this mainboard.

There are 3 DIMM slots on AOpen MK33, which support up to 1.5GB SDRAM. In fact, VIA Apollo KT133 supports 8 memory banks, which allows theoretically implementing 4 DIMM slots. However, AOpen preferred to avoid risks and to stick to PC133 specs advising the use of 3 DIMM modules. Frankly speaking, we checked the work of 3 DIMM modules in MK33 and as we had expected the system didn't give us any cause for concern: it functioned perfectly.

Like the mainboards based on VIA Apollo Pro133A, the BIOS of AOpen MK33 allows setting the SDRAM working frequency equal either to 100 or 133MHz upon the user's desire. Theoretically VIA Apollo KT133 chipset allows clocking the memory for 66MHz too, but AOpen engineers seemed to have considered it useless and didn't include this frequency into BIOS Setup. Nevertheless, AOpen MK33 owners will hardly have any problems with PC100 SDRAM as well as with PC133 SDRAM. Of course, when working at 133MHz the memory will provide the performance 5-7% higher than usual. Speaking about the memory, we should also mention that AOpen MK33 supports the exotic VCM SDRAM, a buffered multichannel PC133 SDRAM, which also increases the performance by about 5%.

As for the CPU configuring on AOpen MK33, we have to admit that it is absolutely impossible. The clock multiplier of most Socket A CPUs is locked and our mainboard doesn't offer anything to change it in any way. We can say the same thing about the frequency. All today's AMD processors support 100MHz FSB that's why AOpen decided not to add any extra FSB frequencies to an OEM oriented mainboard. So, to our great disappointment KM33 doesn't support 133MHz FSB, which may be badly needed for Mustang CPUs this autumn already. Nevertheless, clock generator of MK33 is capable of producing 133MHz that's why we sincerely hope that this problem may be solved in new BIOS versions.

Since AOpen MK33 is designed in MicroATX form-factor, there are not too many expansion slots on it. Besides the already mentioned AGP 4x slot there are only 3 PCI slots. There is even no AMR slot on MK33 though it is so beloved by most large OEMs. ISA slots are also not implemented. The most peculiar thing is a card edge connector with gold finger contact located on the left side of the mainboard. This connector serves for use in NLX-cases when the board is plugged into the add-in card riser with the additional expansion slots. MK33 allows installing full-size expansion cards only in one of the three PCI slots. Unfortunately, MK33 is not deprived of the typical drawback of all KT133 based mainboards: with the graphics card installed into the AGP slot the DIMM clips appear blocked.

Like FIC, AOpen decided to save its engineers time and trouble and designed the MK33 PCB in such a way that this mainboard can be also built on VIA KM/KL133 without any other modifications, which means adding an integrated S3 Savage4 graphics core to the conventional set of functions. However, there is also another side to the picture: MK33 supports only 1 COM-port, because instead of the second COM-port there is an empty spot reserved for the monitor Out. And the connector for the missing second COM-port is located on the mainboard itself. The corresponding external port should be installed instead of one of the expansion cards in the rear side of the case. But the cable isn't included in the package of MK33 board that's why we have to put up with only 1 COM-port for the time being.

AOpen MK33 has VIA 686A South Bridge. One of its functions deals with software AC'97 soundcard realization. So, the mainboard is equipped with AD1885 codec from Analog Devices with a set of basic features. Although the software sound takes about 10% of the CPU resources, it makes the whole system much cheaper, because it allows abandoning an external sound card. If you belong to those users who don't want to sacrifice their CPU resources and are used to high quality sounding with a PCI sound card, then you can disable AC'97 sound via BIOS Setup.

As far as the PCB design is concerned, we can't characterize it as highly convenient, which is a frequent thing for AOpen mainboards unfortunately. The FDD connector is situated in front of PCI slots, which prevents the users from installing full-size expansion cards and makes the cable go through the entire PC case. The power supply connector is also located not in the best place, behind Socket A, which hinders the proper CPU cooling.

The chipset North Bridge is equipped with a green heatsink. Besides, there are a lot of 1500uF capacitors around the processor socket, which improve the signal quality. And it is very important for Athlon systems because the FSB of Athlon systems transfers the data at twice as high rate as Intel systems do. Here we would like to particularly mention that the capacitors do not stand in the way if you decide to use a larger cooler for the CPU. Pleasing, isn't it?

The BIOS of MK33 is based on Award Medallion BIOS v. 6.0 and its interface is very similar to that from Phoenix. At the same time, the amount and functional peculiarities of the available settings make it similar to the classical Award 4.51PG. The BIOS Setup of MK33 includes quite a lot of memory settings as well as the possibility to disable AGP 4x, which helps solve some stability problems with ATI graphics cards. Unfortunately, there is no way to disable FastWrites mode via BIOS Setup, which could be helpful to cure the latest NVIDIA drivers.

As for hardware monitoring on AOpen MK33, the situation here is pretty interesting. On the one hand, MK33 possesses this function, which is included into VT82C686A South Bridge. However, as it comes to practice, the CPU thermal diode and the general temperature sensors appear optional, i.e. are absent in a conventional supply. The fan rotation speeds aren't measured correctly. So, as a result there are only 5 voltages that are really monitored on MK33.

Overclocking

Well, this review seems to have the shortest Overclocking section of all. In fact, MK33 doesn't offer you any overclocking possibilities that's why if you happen to have this mainboard then you should be quite satisfied with the "golden bridges technique" described in great detail on Tom's Hardware Guide.

Performance

The testing system was configured in the following way:

• AMD Athlon 700 CPU
• Creative 3DBlaster Annihilator Pro (NVIDIA GeForce256 DDR) graphics card
• Creative Sound Blaster Live! sound card
• IBM DLTA 307030 HDD
• 256MB PC133 SDRAM by Micron

And here are the results obtained:

As you can see from the charts, AOpen MK33 performs pretty well. But, speed characteristics isn't the main argument when you choose a mainboard from a range of products based on the same chipset. The performances of different products differ so much, that you can't rely only on the benchmarks when selecting the right board. It's much more important to pay attention to the special features of a product. As for the mainboard stability, AOpen MK33 proved just excellent here. The mainboard was very stable, which we had actually expected knowing the highs of AOpen mainboards.

Conclusions

AOpen MK33 appears a very nice thing for OEMs. It is very easy to configure and boasts high performance, stability and reliability. However, the individual users will hardly find many advantages in this product, which could single it out of all the rest.

Highs:

• New AMD Athlon and Duron CPUs support;
• High stability and reliability;
• High performance.

Lows:

• Very few expansion slots because of the MicroATX form-factor;
• No CPU overclocking possibilities;
• Only 50% of the promised hardware monitoring.