VIA Apollo Pro266 + PC133 SDRAM: Shuttle AV32 Mainboard

by FastSite
03/19/2001 | 12:00 AM

It's a pity but we have to state that the planned market onslaught of DDR SDRAM technology has ended up in a failure. Most memory manufacturers were not eager to launch DDR SDRAM modules as there was a lack of chipsets and mainboards supporting this type of memory. As a result, these modules turned out to be much more pricy than it had been expected. No wonder, mainboards with DDR SDRAM support were not in demand. The mainboard and chipset manufacturers were utterly displeased with this state of things, since they counted on the popularity of DDR SDRAM products, which was reflected in their roadmaps. Subsequently, both the parties began to scratch their heads over a possible way out, that is how to sell the newly-created products in spite if the costly DDR memory modules.<%BANNER[article]%>

Ultimately, a compromise was found. VIA, which is nowadays one of the leading manufacturers of DDR SDRAM chipsets, and a number of memory suppliers bargained to sell the DDR modules at a relatively low price together with VIA chipsets. The aim was to let the mainboard manufacturers equip their new boards with DDR SDRAM right away and sell them at a reasonable price. At the same time mainboards manufacturers decided to offer products with both DDR SDRAM and older PC133 SDRAM support. So, the users got a real chance to upgrade their PC133 SDRAM to the cooler DDR SDRAM, when the new modules become cheaper.

There are some other positive moments about mainboards with the support for both memory types. As we have already mentioned in our previous reviews of new DDR chipsets, the use of DDR SDRAM really affects the performance only if used on Athlon based platforms, where the bandwidths of the memory and CPU buses are comparable. As for systems based on Pentium III, it seems useless to equip them with DDR SDRAM, because the bandwidth of Pentium III CPU bus the same as that of PC133 SDRAM bus. This way, using DDR SDRAM on Pentium III platforms makes sense only if its price drops till the level of PC133 SDRAM some day. In fact, this is a very far away prospect still. In the meantime, only VIA Apollo Pro266 based mainboards supporting Pentium III are most likely to get widely spread in the first place, since other manufacturers of Athlon core logic (ALi and AMD) are simply unable to produce as much as VIA. Hence, PC133 SDRAM can become a key feature for VIA Apollo Pro266-based mainboards to find their niche on the market. Especially, since VIA chipset differs favorably from its competitor by Intel, i815EP, as it offers broader opportunities. In particular, it supports up to 4GB of memory versus 512KB of the i815 family and up to 6 USB ports.

It comes logically that in the nearest future the market will be overflown with mainboards based on VIA Apollo Pro266 chipset for Pentium III featuring both 184-pin slots for DDR SDRAM and 168-pin DIMM slots for the regular SDRAM. For instance, all the major manufacturers including ASUS, Gigabyte and MSI have already announced products like that. As far as formerly we highlighted only how VIA Apollo Pro266 works with DDR SDRAM boards and failed to find out how this core logic feels about the common PC133 SDRAM, we assume it to be quite timely to make up for this slip. That's why, as we got hold of Shuttle AV32, one of the very first VIA Apollo Pro266-built mainboards supporting both the memory types, we dedicated a whole article to it.

Closer Look

Before we proceed to the test results, let us dip into the basic characteristics of Shuttle AV32, especially it is the first mainboard with SDR and DDR DIMM slots in our testlab. So, the specs are:

As you might have noticed, we mainly focus on the dual memory support which is introduced on this mainboard. For this purpose the board features two 184-pin and two 168-pin DIMM slots. In fact, the backward compatibility of DDR SDRAM and regular SDRAM controllers is very easy to implement, for both memory types support almost the same data transfer protocols. That is why most DDR chipsets are presumably backward compatible with PC133/PC100 SDRAM. To implement this support, only some insignificant changes in the mainboard layout are needed, so DIMM slots for both memory types don't look weird at all. Moreover, it can help the users to smoothen the transfer from PC133 SDRAM to DDR SDRAM.

Surely, a mainboard can't work with different memory modules at a time. Hence the maximal memory size for Shuttle AV32 is 1GB (i.e., 2x512MB modules). Sadly, the bright idea of dual memory support brings about some serious limitations. Even though VIA Apollo Pro266 can theoretically work with 4GB memory, AV32 doesn't allow using huge memory capacities because the number of DIMM slots for each memory type is not big enough. The board identifies automatically, which type of memory modules is installed, and if DDR SDRAM and PC133 SDRAM are found together the board simply doesn't start up.

Unlike other DDR chipsets, VIA Apollo Pro266 allows clocking the memory asynchronously with the system bus. In practice it means that with the processors supporting 133MHz FSB Shuttle AV32 can work with both: 133MHz PC2100 DDR SDRAM and 100MHz PC1600 DDR SDRAM. Likewise, if we take processors featuring 100MHz CPU bus, we can clock the memory bus of AV32 to work at 133MHz that is to support PC2100 DDR SDRAM. Things stand the same way with SDR SDRAM: as you equip Shuttle AV32 with this memory, its frequency may be 33MHz higher or lower than that of the system bus.

The memory bus frequency is adjusted via BIOS Setup. It's noteworthy that DDR SDRAM and the common SDRAM are configured with the help of one and the same properties page, which settings are responsible not only for the working frequencies but also for CAS Latency and Bank Interleave. All these parameters influence the mainboard's performance and you may vary them to get the most of the memory subsystem.

At the same time, even though Shuttle AV32 supports two promising types of memory, it is intended for FC-PGA processors and thus has very limited application. However pessimistic it may sound, VIA Apollo Pro266 seems to be an abortive case. For this chipset Intel plans to launch only one more CPU with a 133MHz FSB, Pentium III 1.13GHz. Its followers will feature FC-PGA2 packaging and the new Tualatin core. Furthermore, they won't be supported by any of the currently existing chipsets. So, as you buy a Socket370 mainboard today, you should keep in mind that it will be probably impossible to upgrade the CPU in the near future. That's the gravest shortcoming of all contemporary products based not only on VIA Apollo Pro266, but on other chipsets as well.

So, Shuttle could do nothing but make AV32 support the eldest Pentium III CPUs based on Coppermine core, which require very intense cooling. All the capacitors of AV32 are moved away from Socket370. It enables the users to install huge CPU coolers.

Another curious detail concerning the support of different processor and memory types was revealed during our tests. The point is that Shuttle AV32 doesn't work with Celeron CPUs with a 66MHz bus, if the system is equipped with DDR SDRAM. We doubt that there is anyone, who will ever use these components together, but still this incompatibility should not be neglected.

Shuttle AV32 boasts a universal AGP slot supporting both 1.5V and 3.3V AGP 2x and 4x graphics cards. It is provided with a retention mechanism holding the cards in a proper position. Unfortunately, this slot is placed so close to the DIMM slots that the installed graphics card blocks the DIMM slot clips and makes it impossible to install/remove the memory modules when the graphics card stays in the slot.

As for other expansion slots, Shuttle AV32 has 5 PCI and 1 ACR slot. There is no surprise about the absence of the ISA slot: there is no PCI-to-ISA bridge in VIA Apollo Pro266 that is why the manufacturers would have had to add some more microchips to the board and thus make it more expensive. As you may have divined already, no one would ever venture such a thing for the sake of the nearly obsolescent ISA slot. Speaking about the ACR slot, which is situated between the AGP and PCI slots, it is backward compatible with AMR and may be helpful for system integrators, although there are no cards with this interface on the market yet.

Apart from that, system integrators will be happy to find the simplest AC'97 Realtek/Avance Logic ALC100P stereo codec, which enriches AV32 with basic sound playback opportunities (though the CPU gets quite loaded in this case).

Besides DDR SDRAM support, one of the most important peculiarities of VIA Apollo Pro266 core logic is the implemented V-Link bus, which serves to connect the two Bridges of the chipset. The bandwidth of this bus totals 266MHz, that is twice as great as that of the formerly used PCI bus. Thanks to V-Link, the integrated Ultra ATA/100 controller of the South Bridge can presumably transfer the data to the CPU a bit quicker. Moreover, a faster bus enhances the chipset with some new functions. For instance, VIA Apollo Pro266 (and correspondingly Shuttle AV32) supports up to 6 USB ports. Nevertheless, the board is not equipped with the necessary USB connectors and cables, although AV32 features 4 extra connectors for the third, the fourth, the fifth and the sixth port.

Surprising as it may seem, Shuttle refused to use an input-output controller integrated into the chipset South Bridge. It is substituted with Winbond W83697HF chip, which also implements hardware monitoring functions. Due to this chip, the mainboard can control two temperatures, seven voltages and rotation speeds of two coolers out of three, which can be connected to the mainboard. The thermal diodes on AV32 are placed in the usual places: in the center of Socket370 and on the left side of PCB. We were sorry to find out that the board didn't let check the state of the thermal diode integrated into the CPU core.

To sum it up, we would like to pinpoint some drawbacks of the PCB layout. Though there are not many components on this mainboard, Shuttle AV32 is far from being ideally designed. The IDE and floppy drives connectors are situated on the left side of the board, so the allocation of the cables going to them is not optimal. Furthermore, if used in big tower cases, AV32 deprives you of the possibility to connect hard disk drives, which are positioned in the upper part of the case, since the length of ATA/66/100 cables is insufficient. Another thing to brag about is the ATX power supply connector. Since it is put between Socket370 and the ports of the case back panel, the ATX power supply cable will hang over the CPU cooler and this way create problems with heat dissipation.

Overclocking

Evidently, Shuttle AV32 is not meant for ardent overclockers. Of course, the mainboard offers some opportunities in this field, but their list is rather modest. So, what overclocking pleasures are offered by this board?

Firstly, there comes the possibility to change the FSB frequency. It can be changed in two steps: the basic CPU frequency - 66, 100 or 133MHz - is set by four jumpers, which are located to the left of Socket370. After that, you may pass over to FSB frequency fine tuning via BIOS Setup. Here you'll be offered the following frequencies to choose from: 66, 75, 78, 85, 90, 100, 105, 110, 115, 118, 124, 130, 133, 136, 140, 145, 150, 160, 166MHz. There are not so many options, but they are allocated pretty evenly. Nevertheless, they don't suffice for really fine system overclocking, especially in comparison with a number of mainboards that allow an increment of 1MHz.

Secondly, AV32 allows changing CPU Vcore. A corresponding option in BIOS Setup will let you either increase the voltage by 0.05, 0.1, 0.2, 0.3 or 0.4V or lower it by 0.05 or 0.1V.

Well, there is nothing more to describe. Upsettingly, Shuttle AV32 doesn't allow changing Vio, Vagp, etc.

Testbed and Methods

As we tested Shuttle AV32, we were particularly interested in how well the VIA Apollo Pro266-built board could perform with PC133 SDRAM. The previous chipset, VIA Apollo Pro133A, turned out worse than the competing i815 by Intel. That's why we were eager to see if the situation had changed anyhow. Earlier we have already dedicated a whole review to the performance of VIA Apollo Pro266 with DDR SDRAM. In spite of that we made up our mind to investigate the performance of Shuttle AV32 and to weigh it with that of other boards based on the same core logic. For a better comparison we took three more mainboards:

• ASUS CUSL2 - one of the most popular i815-based boards with splendid performance.
• Gigabyte GA-6VX7-4X - a mainboard built on VIA Apollo Pro266 core logic.
• Gigabyte GA-6RX - one of the first VIA Apollo Pro266-based mainstream boards supporting no other memory but DDR SDRAM.

Finally we got five platforms to test:

All the systems worked in Microsoft Windows 98 SE.

Performance

As we showed before, the major bottleneck for all Pentium III systems is the CPU bus. It results in a very slight difference among the performances of the tested systems, though they are based on different chipsets and equipped with different memory types.

Now let us turn to the results of the tests. First, we will see what the situation is like in office applications.

Business Winstone 2001 does not demand a lot from the memory bus bandwidth. That's why there is no heavy divergence in the results. As for the slippage of the VIA Apollo Pro133A-based Gigabyte GA-6VX7-4X, it is for the absence of ATA/100 support, which proves to be crucial for the applications of this test.

As you can see on the chart, content creation applications are the strong side of ASUS CUSL2 built on i815. Even VIA Apollo Pro266-based boards with PC2100 DDR SDRAM cannot break ahead of it. As long as the performance of Apollo Pro266 with PC133 SDRAM is concerned, in Content Creation Winstone 2001 it is far from being brilliant and lags behind even its older counterpart, VIA Apollo Pro133A. Obviously, the memory controller of the relatively fresh VIA Apollo Pro266 and the BIOS for mainboards based on this chipset are not optimized yet.

In this test we can observe the same trend. The leadership in office applications still belongs to i815E. VIA is presently unable to create memory controllers as fast as those in Intel's chipsets.

Now it's the turn of 3D applications.

The results here look fairer regarding DDR SDRAM. Indeed, both the mainboards where this type of memory is used occupy the leading positions. The performance of VIA Apollo Pro266 with PC133 SDRAM is almost equal to that of VIA Apollo Pro133A, that is a bit lower than the performance of the i815-based mainboard.

At higher resolutions it's ASUS CUSL2 based on i815 which is number one, while Shuttle AV32 with PC133 SDRAM considerably overtakes the board built on VIA Apollo Pro133A. It all proves that the AGP bus in VIA Apollo Pro266-based mainboards works faster than in the boards based on this chipset's predecessor. Still, VIA fails to offer as fast AGP port as i815.

In Quake3 the fps rate at lower resolutions is usually heavily dependent on the performance of the memory subsystem. Thus, there is no wonder why DDR mainboards look smarter than their competitors with PC133 SDRAM in this test. We also want to draw your attention to the magnificent breakthrough of Gigabyte GA-6RX in comparison to Shuttle AV32 with PC2100 DDR SDRAM. As you see, Shuttle's mainboard doesn't reveal all the hidden potential of VIA Apollo Pro266.

There is no dramatic change here. But the general divergence shrinks because of the limitations imposed by the graphics memory bandwidth. It is interesting to point out the results obtained on systems with PC133 SDRAM. As in the previous tests, i815 is at the top of the list, but the system built on VIA Apollo Pro266 manages to show better results than that based on VIA Apollo Pro133A.

In Unreal Tournament we can trace the same tendencies as in Quake3, so there is no use to discuss them.

In this test the i815E-based mainboard contrived to surpass Shuttle AV32 with PC2100 DDR SDRAM. In the meanwhile, a similar product by Gigabyte retains its positions and remains faster than ASUS CUSL2. Again we can complain that Shuttle AV32 is not the most successful mainboard based on VIA Apollo Pro266. Nonetheless, with PC133 SDRAM it demonstrates higher achievements than the boards built on older VIA Apollo Pro133A core logic.

Once again, i815E demonstrates outstanding results.

As the resolutions and the amount of textures pushed through the memory grow, VIA Apollo Pro266 with DDR SDRAM rushes forward. We should point out that in Mercedes Benz Track Racing the main hero of this review, Shuttle AV32 with PC133 SDRAM, runs ahead of not only the VIA Apollo Pro133A-based mainboard, but also ASUS CUSL2.

Conclusion

It makes no secret now that DDR SDRAM can't reveal all its smartness in Pentium III systems. So, no one is surprised to see that mainboards built on VIA Apollo Pro266 core logic with PC2100 DDR SDRAM turn out to be no faster than those based on i815E. As for PC133 SDRAM support implemented in VIA's new chipset, we can declare that it is by all means no worse than that of the company's previous core logic, VIA Apollo Pro133A. At the same time, the memory controller in VIA's offspring is again not so effective as that in Intel's chipsets. This way, the strongest side of VIA Apollo Pro266-based mainboards supporting two types of memory - SDRAM and DDR SDRAM - is their multifunctional nature. Besides, it makes sense to use boards based on this core logic only in memory-demanding cases, since Intel offers no mainstream chipsets for Pentium III so far that would be able to support more than 512MB system memory.

All the above given commentaries are true for Shuttle AV32 which is based on VIA Apollo Pro266 and supports two types of SDRAM. As Shuttle is one of the pioneers to launch a mainboard of the sort, it has positioned itself as a source for rational solutions.

Highs:

• Supports both DDR SDRAM and common SDRAM;
• Boasts high stability.

Lows:

• Suffers certain shortcomings in design.