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Abit KR7A (VIA KT266A) Motherboard ReviewAuthor:Date: 05/03/2002
However, the board appeared on the shelves in December. Such short development period can be explained either by a very high level of the developers or by some drawbacks (which is more probable). Note that the times when Abit was an unexampled leader in creation of good overclockable boards passed away. Almost all today's boards have means to overclock processors (and most of them do not use jumpers), and there are also aggressive companies which do their best to take the Overclocking Palm from Abit (Epox, Soltek etc.). Here is one more story unpleasant both for users and for the company. I mean lack of the Athlon XP CPU support in the KT20, KT7E and earlier revisions of KT7A(RAID) boards. Undoubtedly, the ABIT's fans who had no more desire to wait for the KR7A turned to other companies. That is why to return respect Abit had to release a very high-quality and inexpensive board. Did it manage to do it? Abit KR7A specification
Package
Accessories
The package of the new design is, however, in quite sombre colors. But today all manufacturers develop a new design for each new board. The user manual has no noticeable drawbacks. It is very detailed and illustrated. The BIOS settings are paid much attention to, in particular, oveclocking with the Softmenu III. However, there are some minor inaccuracies, but they won't make problems for an experienced user in assembling and adjusting the system. 
Apart from the standard VIA's drivers the CD contains Norton Antivirus 2002, Acrobat Reader and Norton Ghost. Besides, here you can find WinDVD 2000 and several (quite useless) utilities - SoftPostCard, SoftCopier, SoftCardManager and SoftBulkEmail from BuzzSoft.   WinDVD program All these programs can be accessed through a special multilevel shell. 
Examining the boardOn the package you can see a Formula 1 racing bolide, which is quite symbolic. If you look closer at the board you will see it has nothing unnecessary. No integrated sound, no clips for AGP (Formula 1 cars have no radio-recorders or soft leather seat either :)).The textolite is yellow which is traditional for Abit. 
Abit obviously staked on the functional capabilities of the board, not on unnecessary improvements. The first that proves it is the socket. 
On the board, next to the cooler's mount is a plastic strip to prevent the board from damages which can occur during installation of the cooler. The socket is located almost on the edge of the board which makes difficult to affix the cooler if the board is already inside. And it's almost impossible to install large coolers. For example: the Termaltake Volcano 7 was first mounted onto the board (not without difficulty :) and only after that the board was taken in. But all latest Abit's boards have a similar design. Well, it seems that Abit has found an optimal design for its boards. Remember also that it's impossible to install most of coolers without a screwdriver. In this case the fact that the socket is located on the edge may be an advantage, because the screwdriver might jump off :). Next to the socket is a power connector the position of which is quite convenient. 
The only small drawback is that there are two fan connectors between the power connector and the socket. The board sports 5 (!) connectors for additional fans in all. One of them, however, is meant for the CPU's cooler, another for the fan on the chipset. So, the board provides enough support for additional cooling. But it will be quite difficult to estimate effectiveness of cooling, because apart from the processor there is a video card and a high-speed hard drive which also heat much; unfortunately, an external thermo sensor is not supported. By the way Abit was among the first who integrated it in the mainboard, but later the company refused it. Today only the Soltek SL-75DRV2 boards come with an external thermo sensor. 
There is a thermo grease layer between the bridge and the heatsink (most boards use thermo glue), that is why such cooling system gets A. The fan works noiselessly, though any cooler works so for the first couple of weeks. And only after that low-quality fans start producing noise. The AGP slot supports both 1.5V and 3.3V video cards. As I already mentioned, there are no clips to fix the card in the slot (no traces of an AGP Pro at all). Note that such clips can bring troubles if you have a quality case and you have to replace video cards quite often. 
The mounted video card locks clips on the DIMM slots, which creates problems during installation/deinstallation of the memory modules. By the way, there are 4 DIMMs on the KR7A board. Among all its competitors, only the Shuttle AK31 rev 3.1 has 4 slots, others have only 3. It isn't important for an average user - 3 or 4 memory slots. But it is very important for assembling workstations. Unfortunately, I couldn't test stability of operation when memory is installed in all of 4 slots. I just can say that there were no problems with the 256Mb+2x128Mb configuration. The board can take 3 GB RAM in all (or 4GB if register memory modules are used). 
The expandability is excellent - there are 6 PCI slots. Besides, there is a version with an integrated RAID controller. Realizing that far not all users overclock processors Abit made a decision to produce boards with the RAID controller and without it on one PCB. As a RAID controller they use the HighPoint HPT372 chip. It supports hard drives with the new interface ATA-133. Note that hard drives supporting this standard are already available on the market (for example, Maxtor). This is what the KR7A board differs in from the Epox or Soltek ones. However, the real performance boost of the disc subsystem is not great when the new standard is used. A large photo of the Abit KR7A-RAID is given at the end of the review. I have already said that the board lacks for integrated sound. It has no slots for riser-cards either. 
The IDE connectors are located under the DIMM slots, no problems related with connection of the cables occurred. 
The rear panel looks usual. But there's no either a game port or nd audio-outs because of the lacking integrated sound. 
The I/O system is based on the Winbond W83697HF chip. 
Next to it is the BIOS chip. The IDE connectors have the optimal position, unlike the FDD one. The latter is put into the corner of the board and the cable will stretch along the whole case. Besides, there are quite high cases where drives are put too close to the upper panel. In this case the cable can turn out to be short. Well, this seems to be the only disadvantage of the design. 
There is a single jumper - CCMOS (next to the battery). The following figure clearly shows how the components are laid out on the board. 
Connectors for the additional USB ports are, as usual, on the board's edge, next to the PCI6. As you can see, seats meant for the RAID controller and additional IDE connectors are free. Take a look also at the Abit AC2001 chip, 
which is to support the POST code diagnostic indicator. The latter is lacking on the board. There is only space for it next to the LEDs. It seems that this is a 7-segment indicator, like on the Abit BL7 board. Unfortunately, contrary to the BL7, there are no Power and Reset buttons. However, you can get a separate ABIT Postman (DB-20) which must to be inserted instead of one of the expansion cards and connected to the SMB1 (near the south bridge). 
There is one more interesting thing to mention. The board has 3 color LEDs. The red one blinks when you press the Power or the Reset button. The green one goes on when the computer is turned on, and the yellow one is on when the system is in the stand-by mode and the memory/PCI are powered. So, we have the board with the traffic lights: red, yellow, green - go! :))). The system monitoring of this board, as compared with the boards with the VT82C686 south bridge, can monitor voltage -12V and -5V. Other features are standard. 
A little on the BIOS. It is based on the Award BIOS v6.00PG. 
Obviously, there is SoftMenu III item for installation of parameters of the processor's operation. 
Besides, it's interesting to take a look at the memory settings.  (for the more detailed information on the memory settings see "Overclocking & Stability") Overclocking & StabilityThe board incorporates 5 3300uF capacitors and 2 huge ones of 4700uF each. Besides, the board uses a 3-phase feed circuit (like on most KT266A boards).As a result, the board works very stably. It worked both with a power unit from the Genius Venus 230W case and with the PowerMan 250W. In both cases no problems were noticed. 
The overclocking results have exceeded all expectations. The highest FSB frequency the board was able to work at was 175 MHz. It broke a record among the boards on this chipset that I tested. 
It seems that it is the memory (Samsung 256Mb) which prevents further overclocking, because the processor worked at 876Mhz (5х175), and the previous tests proved its operability at 1Ghz. Moreover, the main memory settings corresponded to the maximum performance (Cas2-3-3 ; 4 Bank ; 1T ; Fast Decode - see more detailed information on the settings further). Note that the FSB specified at 175MHz worked actually at 175.376Mhz. At the same time, there are a lot of board makers who cheat by increasing its speed by 0.5 - 1.5Mhz. For further growth of the FSB frequency they would have to increase the memory voltage and timings very much. At such FSB speed one should remember about a considerable load on the AGP and PCI buses. In the BIOS of the KR7A board we can set the following FSBAGPPCI ratios: 3:2:1 and 4:2:1. 
At 180Mhz of the FSB speed we get 90Mhz on the AGP bus and 45Mhz on the PCI one. While most modern video cards are able to work at the frequency up to 100Mhz, hard drives are not. Even if they work, their resource reduces considerably at the frequencies over 40Mhz. A couple of words on the memory timings. 
Abit obviously supposes that the memory parameters will be dealt with by an advanced user. And for example, in the BIOS of the Epox 8KHA+ board in the 'memory timings' section there is item "Performance" (from Normal to Turbo), where even a beginner can lift up a performance level of the memory subsystem. There is no such item in the KR7A's settings, that is why you have to deal with each parameter yourself. Taking into account that after the second unsuccessful start the board returns to default settings, the time of adjusting the board grows up considerably. As I am often asked about some or other settings in the BIOS I decided to pay some attention to it. But note that my comments will be quite brief. CAS Latency Here we can change the number of clocks in which the memory reacts to a request for reading. It is clear that the less, the better. Possible values are 2.5, 2. Bank Interleave This parameter controls access to open pages (or banks) of the memory. Possible values are None, 2 Bank, 4 Bank (sometimes 2-Way4-Way). The most efficient is 4 Bank. Precharge to Active(Trp) Roughly speaking, this is the time the memory takes to recharge. Possible values are 3T, 2T (the fastest variant). Active to precharge(Tras) Unfortunately, I can't put it in simple terms. Anyway, this parameter doesn't affect the performance considerably. Possible values are 6T, 5T (the fastest). Active to CMD(Trcd) Possible values are 3T, 2T(the fastest). Queue Depth This parameter controls the pipeline buffer which is used in operations of data reading from the memory. Possible values are 234 Level. The most efficient is 4 Level, which is set as default. DRAM Command Rate This parameter appeared yet in the KT266 chipset. We can change latency in data exchange between the memory and the chipset. Possible values are 2T, 1T (the fastest is 1Т). This parameter has a great effect on the memory subsystem performance. Fast CPU Command Decode: An insignificant performance boost at the expense of accelerated conversions of processor instructions (address decoding faster by one or several clocks). Possible values are Normal, Fast, Turbo (the fastest). Here are the standard settings for the maximum performance: CAS Latency = 2; Trp=2; Trcd=2 DRAM Bank Interleave = 4 Bank Command Rate = 1T Other parameters do not influence much the performance. It is a very interesting and complicated question how to adjust a system for the maximum performance. Just remember that sometimes it makes sense to increase the memory timings and set a higher FSB frequency; or, sometimes, reduce the FSB speed and increase the CPU multiplier. So, the main conclusion is that the KR7A board is an excellent choice for an overclocker. But you must have high-quality memory (Crucial or Mushkin) to achieve 180 MHz. Now let's look closer at the overclocking. Like on all Abit' boards parameters of operation of the processor can be changed in the BIOS. There is the SoftMenu technology (this board has SoftMenu III). First we can change the multiplier - from 5 to 13 and higher in 0.5 steps. 
Note that when the chosen multiplier value is a fraction (in particularly, 5.5), the board doesn't always set the CPU frequency correctly. I hope this is related just with the BIOS, and in the future versions it will be eliminated. Now let's turn to changing of the FSB frequency. In the BIOS we can set it from 100 to 200Mhz in 1MHz steps. 
As a clock oscillator they use the RTM580-255R frequency synthesizer which allows setting frequencies up to 233MHz. It means that in the future BIOS version the maximum FSB frequency can be increased. 
With the Softmenu III we can change the CPU voltage from 1.10V to 1.85V (for the Duron 1.75V) in 0.025V steps. The support of 1.1V voltage implies a future support of processors based on the 0.13micron process. But remember that Abit KT7E, KT20 and KT7A boards (the first revision) do not support Athlon XP, unlike other KT133A boards. I think Abit will learn this lesson and make no more such mistakes. At last, we can change chipset and memory voltages. Vmem can be changed from 2.55V to 2.85V in 0.1V steps, and Vio - either 3.5V or 3.65V. 
The only thing that is lacking is changeable AGP bus voltage. But if the engineers excluded it, it was necessary. By the way, among the boards in question, only Jetway has a full set of overclocking features including changeable Vcore,Vmem,Vio,Vagp. PerformanceTest system configuration:
 (seconds) The games show the higher performance level as well: 
So, the board shows a performance typical of the KT266A based boards. SummaryFirst of all, I must say that the price is quite high, but fair: an overclocker gets an excellent board with rich capabilities (and good results!) for overclocking. The board can please performance-aware people as well, because it outscores its competitors at the same frequencies.Besides, the board will be an excellent choice for a workstation with large volumes of RAM and strict requirements to stability. At last, it can be used as a base for an entry-level server (for example, for a home network) because it is very stable and because there is a version with the integrated RAID controller. So, the board is good, but remember that it is more expensive than other similar models (Epox, Gigabyte, Soltek) or than boards like EliteGroup K7VTA3 Ver 2. The price difference must be sufficient for a more powerful processor or for more memory. Well, this is for you to decide :). ConclusionHighs:
AdditionHere is the Abit KR7A-RAID mainboard:
Unfortunately, I failed to get the KR7A-133 board with the VT8233A south bridge. This board is packed in the super-box with a handle and a transparent window. Besides, it comes with IDE cables with the Abit's logo. |
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