Register 95:1 set using Wpcredit cools CPU temp by 16C !!

[gustavo]

Any official documentation regarding PCI Configuration Registers for KT266 chipset ?

I own an MSI K7T266 PRO (VIA KT266 based) Windows 2000 Professional SP2

I downloaded a program named WPCREDIT and documentation regarding PCI Configuration Registers for the KT266 / KT266A chipset from http://www.viahardware.com/download/viatweak.shtm

Specifically I point to the information about the register [95:1]:
[95:7]=MWQ Time Slot While MWQ is full (units of 8 CPUCLKs)
[95:6]=(same as above)
[95:5]=(same as above)
[95:4]=Write Policy CPU to RAM 0=FIFO>2 or idle 1=disable
[95:3]=PMR Cycle Control 0=Stall if MWQ full
[95:2]=FID Command Detect 0=disable 1=enable
[95:1]=HALT Command Detect 0=disable 1=enable
[95:0]=(Reserved)

That register by default is unset. When I set the bit [95:1] the cpu temperature at idle went down from 49C to 33C. Incredible output !!!

Is there any official information regarding this ??
Is there any reason why [95:1] is not set by default?
Are there any side-effects of setting it ??
Any idea will help.

Many thanks.
Gustavo.- :Q

 

[CTho9305]

assuming thats the "bus disconnect" deal which drops the processor into a much lower power mode than normal HLT instructions... its disabled by default for a few reasons:
1. IIRC, the original AMD docs didn't have necessary (or correct) information for resuming the processing - specifically, some timing. Wrong timings = hard lock (reset button required)
2. systems with half-multipliers (i.e., 8.5) tend to lock - they don't resume properly.

For my system (slot tbird 700, asus k7v) setting the bit locks the system as soon as the processor leaves full load (like, if I quit dnetc/seti/genome@home, instant hard lock )

this may be of interest.

 

[gustavo]

CTho9305:

Mine is a TBird C 1 GHz (7.5 multiplier) and no locks at all
Strange thing: case temp gets higher than cpu temp at idle
My primary concern is: You think I am on the safe side leaving the bit set ??

I allready use the NT kernel (Win2k) so I dont understand the "bus disconnect" deal you are describing, could you explain it a little more please ??


Thanks, somebody at least has an idea !!!

 

[CTho9305]

search the highly technical forum. someone asked that there.

 

[gustavo]

Yeap, that was me.
Thank you.-