k6-2 300 mhz

[Alan Garrison]

Mike Rambo <mrambo@lsd.k12.mi.us> 05/04/00 11:59AM
> Alan Garrison wrote:

>> On an Athlon system, going from PC100 to PC133 isn't a huge leap
>> (a bit though).  If you really want to fly, you are going to have...

> Putting in memory
> which is capable of faster operation will not increase the 
> machine speed because all reads and writes are still 
> accomplished in a set number of clock
> cycles whose speed is determined by the base clock on the motherboard
> (motherboard base speed is predetermined and not affected by other 
> devices or modules that are installed).  

Sure, that's not quite what I said.  Newer Athlon boards can handle 
both 100 and 133 speeds.  Then again, I'm no hardware guru.

If this helps, some info from Anandtech:
*****
http://www.anandtech.com/printarticle.html?i=1142
*****

The method of overclocking that we are most used to, courtesy of the 
multiplier locked Intel CPUs that we've had for such a long time, is 
accomplished by increasing the FSB frequency.  Since the CPU derives 
its clock speed from the FSB frequency (CPU Clock = FSB x Clock 
Multiplier), increasing the FSB frequency will increase the CPU clock 
speed and thus overclock the CPU.

The major benefit of this method is that the overclocking can generally 
be accomplished without even taking the case off of your computer.  Most 
motherboards allow for the FSB frequency to be adjusted in the BIOS 
setup utility (generally under the Chipset Features/Advanced Chipset 
setup or its own special Frequency Setup section) so with a few 
keystrokes you can be off and running at your overclocked speed.

The first misconception that must be cleared up is that the Athlon's FSB 
actually runs at 100MHz and not at 200MHz.  The EV6 bus transfers on 
both the rising and falling edges of the clock (instead of just the 
rising) and thus the effective transfer rate over the EV6 bus is equal 
to that of a 200MHz FSB, but the actual FSB frequency is 100MHz.

The downside to increasing the FSB frequency, as we briefly mentioned 
before, is the fact that most of the components on the motherboard 
derive their operating frequencies from the FSB frequency and increasing 
the FSB frequency will, in turn, increase their frequencies as well.  

For example, the PCI bus operates at either 1/2 1/3, or 1/4 the speed of 
the FSB.  The 32-bit PCI bus specification calls for an operating 
frequency of 33MHz, and if your FSB is set to 100MHz then, by using the 
1/3 divider, the PCI runs at the appropriate 33MHz setting.  Most PCI 
devices have no problem running at frequencies up to 37.5MHz, and there 
are usually very few problems until you get above a PCI bus frequency of 
40MHz.  If you take into account the fact that there is a ¼ PCI divider, 
achieving a PCI bus frequency greater than 40MHz would require you to 
have an FSB frequency greater than 160MHz.  

The AGP bus is designed to run at 66MHz and operates on a fraction of 
the FSB frequency.  This fraction is determined by the North Bridge of a 
chipset, which in the case of the AMD 750 chipset is the AMD 751 North 
Bridge controller.  The 751 only supports the 2/3 and 1/1 AGP clock 
dividers, and most AGP cards have a problem working at frequencies above 
83MHz.  This means that for most AGP cards, a FSB frequency too far 
above 124MHz would be difficult to pull off.

The memory bus on the Athlon is currently designed to run at 100MHz; 
however, the tolerance level of the memory bus is normally dependent on 
the memory you use.  For example if you use PC133 memory that is rated 
for operation at 133MHz, then you should not have any problem if your 
memory bus is running at 133MHz.  

The Athlon's EV6 system bus is designed to run at speeds of up to 
200MHz, and according to those that we have spoken to that have a part 
in designing the future EV6 based motherboards, reaching that 200MHz 
goal isn't a major problem, it is mainly an issue of implementing it on 
the motherboard rather than tweaking the chipset.  So increasing the FSB 
frequency shouldn't be limited by the EV6 bus anytime soon, although the 
motherboard may be the limiting factor in this case.