EPOX EP-KTA3 Wont boot at 133Mhz Bus?!?!

[PassatVR6]

I unlocked my 850 Tbird today with a conductive pen and got to experimenting. i set the voltages to 1.85 a 3.5vio.

I successfully booted into windows at 9.5X100mhz = 950 mhz with the RAM set at 133mhz . In the bios i have it set to Auto Detect RAM Clock.

Now, I set the multiplier down to 7.0 in the bios, shut down, and switched the jumper on the motherboard (JP5) to 133Mhz bus and when I try to reboot, i can hear it counting the RAM, but the monitor wont engage (screen stays black). I have 512MB PC133 RAM so the bus speed shouldnt be a problem.

Right now I am running 9.5 X 102 = 970 MHZ with RAM set at 136Mhz and the system is rock solid. All I have is the heatsink and Fan that came with the CPU/Board combo and it has thermal grease on there too.

I would like to be able to run my system at 7.5 X 133 = 998MHZ or even 7 X 133 = 931mhz.. i want to get the bus kicked up to where it should be!~133.

Any ideas why it wont boot like that?

Also i copied down the number off my tbird 850: ADFA0036TREW i think thats what it said. Is this a good CPu for overclocking?

Thanks,
Matt

 

[DaddyG]

VWman, the EPOX mobo has some known issues with 133 fsb but the following might help. The mobo will not switch to 133 unless you have the BIOS set to defaults. Some options, like Hostclk + PCIclk, which you used to get your RAM to 133 are not compatable with 133 fsb. Set your multipler lower but leave everything else at default. If this doesn't work then you still have a couple of options. You will need to configure your L6 bridges to use a lower default multiplier on initail power on. Your L6 bridges should look like this . : : | : if you connect the bridges to . | | | : your cpu will initialize at 7X which should be OK at 133. You can tweak the multiplier or FSB higher to find the sweet spot.

While your connecting the L6s, you should also connect all the L7s to initialize the cpu at the higher default voltage of 1.85. Upping the voltage in the BIOS is not the same, as the cpu must read the BIOS settings from CMOS, and then set the voltage, its better to have the cpu default the voltage higher.

 

[PassatVR6]

Okay, Thanks DaddyG, those suggestions are what I will try when I get home from work tonight. So I just have to get the system to get booted up and intialized at say... 7X133=931 w/ a direct start at 1.85V then once im in the bios i can change the multiplier up to.. 7.5X133= 998 and it will all be good to go? Once I reboot will the settings stay at 998mhz or will it default back to the 931Mhz? Im assuming the Bios takes over and saves the settings from then all out, just making sure.

Also, where can I go to look up other Tbird Serial numbers and see their overclocking rate of success. I have a week 36chip (ADFA0036) any comments on the likelihood of getting over a Gig out of it?

Thanks,
Matt

 

[DaddyG]

You got it VR6. You can up the multiplier and save it in the BIOS. Also, you can lower the voltage in the BIOS if its stable. It'll still use 1.85 for power on and initialize but lower it latter.

Overclockers.com, I think, had a week chart of OC success but its still a crap shoot.

 

[PassatVR6]

Okay I was successful in obtaining the 133Bus. I did like you said, connected the L7's for 1.85V on power up, and I set the L6 to a multiplier of 7. Now it boots at 933Mhz. I tried playing around trying to tweak it up from there. After upping voltages to AGP 1.6 and I/O to 3.5 I successfully booted into windows at 7.5X133= 1 gigahertz. I could run IE and AIM just fine. Then I decided to do a few benchmarks. CPUMark crapped out when I tried to run it. Then I tried to run Sisoft Sandra and I got the BSOD! After playing with the settings in the bios and many reboots, I could not get the computer to be stable at 1 gigahertz. Finally I backed down and tried 952Mhz @ 136bus and it still crapped out which is weird because the night before I ran Sisoft Sandra at 970Mhz looping all night and it had no problems. Could it be my wimpy Powerman 235Watt Power Supply holding me back? Or does it sound like a heat issue? I am using the HSF w/ thermal paste that came with my moboard/ cpu. It said it can handle up to 1 gigahertz Athlons. Oh well guess I have to buy a few more goodies!

 

[DaddyG]

Good to hear that you had some success . Now, we need to find out what is limiting your system. I am assuming that when you select 133FSB, that your PCI/AGP buses get automatically set to the lower 1/4 divivder ?? Double check to make sure. You'vr run your memory at HSTCLK + PCICLK using 100FSB so 133 for your memory appears good.

I suggest that you over-ride the spd settings of your memory and select the absolute slowest settings (8/10ns) . If the system becomes stable, then tweak the settings higher in a slow and controlled test environment.

Your 235watt PS is definitely suspect, and AMD approved 300 watt supply would be appropriate.

Heat is also a possibility, when Ocing I'd recommend the TAISOL CGK742092, Globalwin FOP 38 or Alpha 6035 and high quality thermal compound (Arctic Silver).