Many web sites have posted articles and quick notes on stability problems with computer systems based on the VIA KX-133 Athlon, and Apollo Pro 133A Pentium III chipsets.  Many posts on hardware message boards have proclaimed that VIA chipsets are vastly inferior to Intel chipsets, including the old BX chipset.  Well, say what you will, but even Intel has had trouble topping the feat that their engineers accomplished when they turned out the Northbridge design for the BX chipset.  Both Direct Rambus DRAM's serial interface, and VIA's PC-133 SDRAM interface loose when pitted against overclocked BX systems with CAS-2 PC-100 SDRAM.  But the question here is whether the VIA chipset is inherently unstable when compared with Intel's BX chipset.

  Recently, Scott Wasson of the Tech Report wrote a piece on his experience with stability testing with several KX-133 and Apollo Pro 133A systems running different operating systems.  You can read his results here.  His conclusion was that when set up properly, VIA-based systems are as stable running Microsoft operating systems as systems based on Intel's chipsets.  

  We have found that any system running Windows can be unstable if all the software and drivers are not installed just right.  With VIA-based systems, you need to get 3 things right (note: install the miniport driver first).

1) The newest VIA AGP miniport driver (install the latest 4-in-1 VIA driver, which you can get here, currently, ver. 4.22)
2) The latest version of Direct X, which you can get here (currently, 7.0a)
3) The best possible NVidia video driver (currently, Detonator ver. 5.30, 5.32 or 5.33), which you can get here.  All three work well.

  To do a small, un-scientific study of my own, I put together an Athlon 700 system from parts in stock, including an Asus K7V motherboard, 128MB of PC-133 SDRAM and an Asus V6800 "Pure" DDR GeForce card. I made a full system with an IBM 75GXP 30GB drive, Toshiba 12X DVD drive, an SB Live X-gamer card, a USR 56K modem, and an Iomega 250 ZIP drive, all installed in an Antec KS 188 case with 300W power supply.

  The system had a clean install of Win98SE-plus, and no applications were installed on the hard drive except for some benchmarking software. I installed the latest VIA AGP miniport driver (4.22), and Direct X 7.0a.  I set the AGP mode to 2X, since the 4X setting can cause problems.  I used the Detonator 5.30 unified video driver from NVidia.  I then overclocked the front side bus setting on the K7V from 100MHz to 107MHz, giving the system a speed rating of 749MHz.  Next I used NVidia's Coolbits to overclock the V6800 from 120MHz core/300MHz memory to 128MHz core/318MHz memory. I could have gone further on overclocking the GeForce, but I didn't want to push my luck.

  The one big compromise I had to make with the K7V was to keep the CPU/memory clock ratios equal, rather than setting them to a 3:4 ratio as I would have liked. So the memory in this test was running at 107MHz. The VIA Northbridge does not provide the kind of memory performance that the BX chipset does, so boosting the memory speed above the front side bus frequency would have been helpful. VIA still has some work to do on their Northbridge as far as memory performance goes.

  I started the system up with a minimum of software running in the background (no Norton or other background applications).  Then I started up the newest version 3D Mark 2000 (version 1.1) (Madonion.com) and set it to loop the demo indefinitely, with sound on.  That was at 11:00am on Sunday, July 23rd. As I write this, the system chugs away nicely, well past the 72 hour mark.  It has not hung or dropped to the desktop even once so far.  I must admit, I'm a little surprised myself, most Windows computers, especially overclocked ones, hang after 5 to 10 hours of continuous high-performance operation.  I'll let you know when the system blinks.  If it does not die during the next few days, I'll have to stop the test. After all, we have to sell this computer eventually!

Conclusion: 3DMark 2000 is a very demanding 3D application.  Overclocked GeForce cards running in overclocked Athlon systems push this type of application even further.  Windows 98SE is not considered a particularly stable operating system, so with that in mind, I'd say that the VIA chipset did pretty damn well in my little test. If set up correctly, a VIA-chipset system running Windows 98 can be extremely stable.

  Keep in mind that most computers running Windows would not do this well, mainly because they have tons of software loaded, and the Windows Registry is chock full of junk.  So if you try this at home, and it doesn't go for days without dropping to the desktop, don't feel bad.  After all, we are talking Windows here.

First Update: Still going strong at 4pm on Wed. July 26th (77 hours and counting)

9pm Update:  The demo was still running just fine at 9pm on Wed. (82 hours and counting)
(PS: The court injunction just handed down against Napster is completely irrational.  Shouldn't all tape recorders be banned then?)

9am Update: 3D Mark 2000 was still running great at 9am on Thursday, July 27th (94 hours and counting)

8pm Update: You guessed it! The system was still running just fine, thank you, at 8pm on Thursday (105 hours since it started, and still counting!) 
(PS: Whoa! Did you hear? An Intel DDR Pentium 4 chipset!! Nice.)

9am Update: This is kind of amazing, the system was still running the demo at 9am Friday morning, July 28th. (118 hours since the demo loop started) 

9pm Update:  Still going at 130 hours!

9am Update:  Still going at 142 hours!  This despite a very large thunder storm last night, which caused the power to flicker several times.  The system is running on a UPS (uninterruptible power supply), so it kept on a chuggin'!

12:30pm Update (Sat, July 29th):  Just after the system passed the 6 day (144 hour) mark at 11am, I noticed the demo loop was running a little slow, and that the reflecting pool, and water sphere had corrupted polygons and textures. All other parts of the demo still look correct, so it's just a problem with moving, see-through reflective surfaces, as you can see in this photo that I just shot from the screen.

 The demo continues to run now, and the system has still not hung, but I consider the stability test over.  And the verdict is clear.  Athlon/VIA systems can be fantastically stable while running Windows98, even when lightly overclocked.  This system ran the 3D Mark demo for 6 days continuously, before showing any signs that it needed a reboot. And at 12:30pm, it's still running with the only problem being the rippling,  reflective water surfaces.

  Both AMD processors and VIA chipsets will continue to evolve and improve.  I'm very happy with the products from both companies right now.  And considering how small these companies are compared with Intel, I'm impressed.

Final Update:  Just for the heck of it, I left the system running overnight.  And as of 11am, Sunday July 30th, 7 full days (168 hours) after starting the demo loop, it is still running.  The frame rate is down somewhat, and the transparent water surfaces still have corrupted polygons and textures, but it hasn't hung or dropped to the Windows desktop!  It's time to shut her down.  You did real good VIA, and we can't forget to give an honorable mention to AMD, Asus, and NVidia!