BlueSmoke - Review : ASUS TUA266

		Date	: Oct 22nd, 2001
		Category	: Motherboards
		Manufacturer	: ASUS
		Author	: Jin-Wei Tioh

Socket-370 processors, be they Intel or Cyrix, are all designed with a non-source synchronous data bus. Both the Athlon and the Pentium IV employ source synchronous clock technology; the Athlon with it's 266MHz DDR FSB; the Pentium IV with it's 400MHz FSB. However, a 133MHz FSB is the limit for Socket-370 processors. This effectively means that the provision of a wider memory bus will not significantly boost overall system performance, as we shall see later on.

Nonetheless, numerous manufacturers have came out with Socket-370 DDR solutions, mostly based on the VIA Apollo Pro266 or the SiS 635. Not wanting to be left out of the game, ASUS has introduced their second Tualatin-supporting motherboard, the TUA266. No doubt the Tualatin is destined to obscurity thanks to Intel's aggressive pushing of the Pentium IV, it is still the best Intel clock for clock performer in today's applications. Thus, many Intel fans have been hunting for these elusive CPUs. Without further ado, let's see how the TUA266 fares, and how the ALi Aladdin Pro 5T compares to the Intel i815E/EP chipset.

ASUS chose to go with a more traditional brown PCB. However, it is huge, sharing the AOpen AX3S Plus' dimensions of 12" x 9.5" (HxW) and potentially causing end-users with smaller cases some grief to install. In part, this is due to the high number of memory slots present; 2 184-pin DDR DIMM slots and 3 168-pin SDRAM DIMM slots. That said, the layout of the TUA266 is commendable, with component placement being carefully thought out. The ATX power supply header sits parallel and next to the SDRAM DIMM slots, which is a fine arrangement albeit with one minor drawback : the ATX power cable will hang over the DIMM slots, making DIMM installation and removal somewhat inconvenient.

Strangely, the DDR slots are positioned about a quarter inch below the SDRAM slots. The DDR slots could stand to be a bit higher as one has to remove the AGP card before installing or removing any DDR DIMMs. Additionally, the DDR slots are closer than usual to the CPU socket. This could negatively affect stability as the exhaust airflow from the heatsink/fan unit is obstructed, dumping additional waste heat to the installed DDR DIMMs. As done on all motherboards, the front panel connectors are placed in the lower-left corner of the motherboard, ensuring that the cables do not get in the way of any expansion slots.

RAID functionality is absent from the TUA266, nor does it look as if there will be a RAID version. The IDE headers are located toward the bottom of the motherboard, roughly an inch from the SDRAM slots. This minimizes potential cable clutter because the headers are closer to the storage devices. Due to the placement of the ATX power connector, ASUS relocated the floppy header rightwards, next to the BIOS. Fortunately, they oriented it parallel to the PCI slots, so that all slots on the TUA266 may be populated with full-length cards.

ASUS decided to integrate only 2 USB ports, including 2 USB headers on the board as well as a bracket with an additional 2 USB ports. The additional USB headers are placed toward the lower-left of the motherboard, an ideal location as some casings such as the CoolerMaster ATCs include front USB ports. You would have surmised by now that the ALi M1535D+ South Bridge supports a grand total of 6 USB ports!

Capacitor placement is near perfect, with only 2 1500uF capacitors encroaching on the CPU socket. Unless you need to utilize a very large heatsink, the TUA266 should present no problems, as we readily verified by installing the GlobalWIN FOP-38 and the Thermosonic ThermoEngine.

The M1651+ North Bridge, the core of the Aladdin Pro 5T chipset, sits between the CPU socket and the AGP slot. It provides all the major features of the chipset, namely DDR, 66/100/133MHz FSB as well as AGP 1x/2x/4x support. ASUS opted for the classic green North Bridge heatsink, something not often seen since the venerable 440BX chipset. The heatsink is a tad small but is sufficient as the North Bridge doesn't get overly hot under normal operating conditions. You can however opt to install an active cooling solution such as the Thermaltake Blue Orb. This shouldn't present any problems since ASUS has provided ample allowance.

The TUA266 is that it comes equipped with an AGP Pro slot, something that seems to be commonplace among ASUS motherboards, but rarer among other brands. The slot comes pre-installed with a safety tab, which should not be removed unless an AGP Pro card is being used. Otherwise, the card might slide back and get damaged. Another interesting aspect is the TUA266's DIMM slot configuration. Unlike other Tualatin boards, the TUA266 sports 2 DDR DIMM slots and 3 SDRAM DIMM slots.

It supports either 2GB of DDR-SDRAM or 3GB of SDRAM. This is supposed to be one of its key advantages, as this configuration will allow the end-user to make use of his / her existing SDRAM while waiting for the prices of DDR-SDRAM to fall. As mentioned earlier however, no Socket-370 CPU features clock synchronous clocking, meaning the FSB is limited to a single data rate and that doubling the peak memory bandwidth (via the use of DDR-SDRAM) would not greatly add to overall system performance.

The ALi M1535D+ South Bridge is part of both the Aladdin Pro 5T and the ALiMAGiK 1 chipset (see our K7AMA review), which boasts support for the Ultra-ATA 100 protocol and 6 USB ports. Basically, the M1535D+ is on par with the VIA 686B South Bridge. For expansion slots, ASUS chose to go with the OEM oriented 1/5/0/1 (AGP/PCI/ISA/AMR) configuration. The inclusion of an AMR slot is rather pointless by many accounts as peripherals are virtually non-existant. All expansion slots are capable of ccommodating full-length cards.

The distribution and quantity of capacitance are critical considerations in designing a stable motherboard. There are 13 1500uF, 3 3300uF and 7 1000uF capacitors, not counting the numerous ones that are less than <1000uF. ASUS is known to aim first for stability then overclockability, and the TUA266 reflects this design principle. Overclocking is not a neglected aspect however, as ASUS included fully jumper free FSB adjustment (admittedly close to standard fare nowadays) and DDR DIMM voltage adjustment.

As with the trend exhibited in nearly all recent products, ASUS added the OEM-ish feature of integrated audio. The C-Media CMI-8738 PCI audio controller used is a higher quality part, boasting A3D and DirectSound 3D compatibility, 4-channel audio and SPDIF input/output. It's actually a rather decent audio solution, and being hardware-based hogs less CPU time while providing more functionality than competing AC'97 solutions.

The TUA266 also sports the iPanel, an optional accessory. The iPanel is a module that is installed in a free 5.25" drive bay and comes in two version : basic and deluxe. The basic version comes with a 4-digit display that keeps the end-user up-to-date about current system status and can report errors, several program quick-launch keys, and 2 USB ports. The deluxe version adds serial ports and audio jacks. An ASUS motherboard complemented with either iPanel will have good diagnostic capabilities.

To round out the bundle, ASUS includes the appropriate cables and headers, a detailed manual and CD which contains the drivers, utilities and a full version of PC-Cillin 2000 for Win9x/NT/2000. This saves the end-user time, money and inconvenience of separately purchasing an antivirus program, though this reviewer cannot personally vouch for the software's quality.

The TUA266 put through it's paces...

For the results below, the TUA266 was run with standard parameters (ie. no overclocking) at 733MHz (5.5 x 133 FSB), CAS 2. Please note however, that you shouldn't compare the results obtained here to rate a Socket-A motherboard and vice versa.

We would like to take a moment to thank the sponsors that have made this review possible. The Spire 5P53B3 was supplied by ByteCom Fanner B.V., the Artic Silver II TIM by Arctic Silver LLC, and the Siluro MX400 by ABIT. The TUA266 was loaned to us by ASUS.

In addition to tests using standard parameters, we performed overclocking tests to ascertain the highest FSB speeds the system could sustain. We started by setting the CPU to run at 133MHz FSB with a multiplier of 5.5 (for a speed of 733MHz) and verified its stability via informal testing using Ultra-X's RAM Stress Test, Stability Test and HotCPU. The FSB was gradually increased the tests repeated. All tests were done BIOS default memory settings with the CAS latency set to 3, to minimize the chances that the RAM was the limiting factor. Ultra-X makes some of the best professional PC diagnostic tools on the market, and quite a number of people use them on a regular basis including some of our acquaintances. Their RAM Stress Test has proven quite effective in ferreting out any memory instability problems, which is one of the things that is evaluated when increasing the motherboard's FSB.

ASUS has set a much more conservative FSB ceiling of 166MHz, compared to the AOpen AX3S Plus' unbelievable 248MHz. We reached the stability limit at 160MHz, with the processor running at 880MHz (5.5 x 160). This is a full 21% increase in FSB, which is a good showing by any standard. The multiplier on non-engineering sample Intel CPUs are locked, which does make our overclocking tests somewhat questionable. However, until we can acquire an engineering sample CPU, we can only assume that 160MHz is the limit for the TUA266.

An overview of the TUA266's good points :

• Rock solid stability under both standard (133MHz FSB) and overclocked (up till 160MHz) conditions.

• Excellent layout, save a minor quip or two. All expansion slots are capable of accommodating full-length cards, the 3 fan connectors are sensibly placed, IDE and floppy headers are placed to minimize cable clutter and maximize airflow to CPU. More than sufficient allowance for more powerful chipset cooling solutions such as the Blue Orb.

• SDRAM and DDR-RAM support, which gives the end-user a lot of flexibility in choosing memory types. However, please note that our tests indicated that there was virtually no increase in overall system performance when using DDR-RAM.

• Very overclocking friendly, featuring an effective and easy to use jumperless system, allowing 1MHz FSB increments from 66 - 166MHz. Even DDR DIMM voltage is adjustable.

• Integrated hardware-based audio. With A3D and DirectSound 3D support, it is actually quite a decent audio solution.

• Nice software bundle, which includes the ASUS PC Probe system monitoring utility and Trend PC-Cillin 2000 for Win9x/NT/2000.

...and bad points :

• Ho hum aesthetics, with the standard brown PCB and green North Bridge heatsink.

• Expansion slot configuration of 1/5/0/1 (AGP/PCI/ISA/AMR). Although 5 PCI slots are sufficient for most users, 6 PCI slots would have been even better. While being beneficial to OEMs, the lack of AMR peripherals virtually renders the slot a waste of space.

• DDR DIMM slots are a little too close to the AGP slot which makes DIMM installation / removal more inconvenient. The ATX power header sits right beside the SDRAM DIMM slots, causing thee ATX power cable to obstruct access to all memory modules.

• No memory interleaving options in the BIOS. The lack of interleaving hurts memory bandwidth scores, even with all the memory timings upped to the maximum, though it still manages to tie with the i815E-based AOpen AX3S Plus.

• Size. This thing is a behemoth, much like its Socket-370 competitor, the AOpen AX3S Plus. While this shouldn't bother most users, those with more compact casings might find installing the TUA266 to be a problem. It barely fit into our testbed's casing.

ASUS wanted in on the Socket-370 DDR game and thus released the TUA266 based on the Aladdin Pro 5T chipset. Stability is top notch and its SDRAM-based performance is good, keeping neck and neck i815E-based AOpen AX3S Plus. The provision of both DDR and SDRAM support gives the end-user excellent flexibility, although the performance benefits gained by using DDR-RAM are questionnable. Component layout has been well done, reducing cable clutter and leaving plenty of allowance for alternative cooling solutions. Overclockability is excellent, with the TUA266 maxing out at 160MHz. The integrated hardware-based audio is also a rather decent solution. To top it off are the software bundle which includes PC-Cillin 2000 and the ASUS iProbe monitoring utility, as well as the good documentation. Unfortunately, the TUA266 falls short in memory bandwidth, expansion configuration and aesthetics. Although it tied with the i815E-based AOpen AX3S Plus in memory benchmarks, the lack of memory interleaving held back the TUA266's full potential. While a 1/5/0/1 (AGP/PCI/ISA/AMR) expansion configuration is enough for most users, power users would have preferred to do away with the onboard sound and the AMR slot, replacing it with an additional PCI slot or an ISA slot for legacy support. The motherboard's sheer size might also pose a problem for some end-users. Lastly, there aren't any outstanding aesthetical features on this motherboard, with its traditional green North Bridge heatsink and brown PCB. This last point would only be important to case modders, since the motherboard is practically out of sight in normal cases. If you're currently looking toward a new Pentium III-based system, or especially a Tualatin-based system, you might as well pick the ASUS TUA266. Solid stability and great overclockability. Recomended!