Asynchronous Bus Guide - PAGE 1

Currently the most popular chipset for a single CPU Athlon system is the KT333. It supports things like ATA 133 and DDR333 that have quickly become standards. Most KT333 board manufacturers have opted to use an asynchronous bus to support DDR333 instead of adding in a 1/5 divider and supporting a true 166Mhz bus. I'm not a big fan of this at all. The gains of running an asynchronous bus aren't as big as you'd expect.

I was doing a bit of testing for myself wondering how much faster things would be when running a true 166Mhz FSB instead of using asynch. The gains are big enough to do a quick writeup :) In doing so I would like to stress to all motherboard manufacturers *cough* MSI *cough* that it IS worth your time adding the extra divider! Some people out there actually believe that running an asynchronous bus is good enough. I don't believe it is! It should be better...

Most people out there have CPU's that can handle a 25% overclock or they at LEAST have them unlocked. Most clock generators being used on boards today support not only the 1/5 divider but often a 1/6 and 1/7 as well. Most companies out there have started giving us options for these insane bus speeds (some as high and over 250Mhz) yet most of them only support a 1/4 divider and the GOOD ones support a 1/5. I can't help but rant... The clock generators on most boards that come through here support 1/5, 1/6 and 1/7 PCI dividers yet they're never added. We see things like this all the time. Do the companies not realize there's simple software things that they can do to make their board considerably better?  I dig around chipset registers a lot so I generally have a pretty good idea of what could be added to a BIOS. That only gets me mad when some big tweaks/features are left out. The only way that they will ever see a need to add these is if the hardware review sites out there ride them and dog them when there's a lot of things missing. Unfortunately most of the guys writing these reviews are just happy to get the free hardware.

For the best prices on KT333 boards click here.

Testing

We've seen 2 KT333 boards so far and I haven't been impressed at all by the asynchronous bus.

I am posting the exact memory and AGP settings that I use for all of our testing. Driver versions are also posted. All memory and AGP timings not noted here are left at their BIOS default.

RAM settings

Cas2
Precharge 2
RAS Pulse 5
Ras to Cas 2
4 way bank interleaving
1T Command rate

I have chosen to use highly tweaked memory timings to reduce things like latency and achieve higher overall bandwidth. I believe by doing this it may show

AGP settings

64Mb aperture
Fast writes enabled
AGP 4x
Other AGP read/write related items disabled