Athlon and GFD's...

[lindberg]

Does anyone have a GFD on the deskboard, if so could you check which of the Vcc and GND pins that are hooked together..
According to Dr.Tom (tom's hardware) It should be A8, A12 and A15 to Vcc; and B1,B4,B8,B12,B15 and B17 to GND. I've made my own GFD (not following tom's flaws) and as soon I hook up the GFD my computer won't start..Even with all dipswitches off (=Not connected) it won't start . So I think that there is an error in the Vcc circuit(core voltage) or even more probably in the GND-circuit..
If I only had a GFD so I could check which one of the GND pins that are connected together.
Could somebody please take 5min off your time and follow a few traces on the GFD-board?
A-pins are on the processorside of the processor board
B-pins are on the backside
No.1 pin is the one most far from the processor and pin 20 is the one closest to centre of board (both sides).

Thanx a lot if anyone would check it out..

[Greebe]

A8, A12, A15 and B1, B4, B8 ,B12, B15, B17 are connected (A's to A's and B's to Bs within the Athlon PCB)The A's leg is 3.3Vcc (not Vcccore) and B's are ground.

Tom's schematic was drawn with a couple flaws, one of the switch positions was wrong and he spec'd the wrong resistors for VID0-3

If you have a schematic I'll make any corrections to it neccessary for it to work.

[lindberg]

Thanx greebe, for replying. I got it to work yesterday though, I cut away the (B4 and) B17 pin, and after I've cut the B17 pin it started to work. I've got a asus k7v mobo and before I'd always get that crap weeewoo-sound! One, thing that I noticed, I needed to set Vcore to 1.8V on the GFD before my mobo would accept even default multiplier..
strange...

[lindberg]

The cache is changed to 2/5, it would run at 1/2 up to 840 (=420MHz cache) but not even 425 MHz cache would run I checked my cache and if I remember correctly it was 3.1ns chips and the athlon core was 700.
I'd like to raise the Core voltage a bit more but I'm already running 43 degrees celcius, I'll wait until I hook up the watercooling with doing that
Maybe that 950+ would be possible at 2.00V or 2.05V..

[This message has been edited by lindberg (edited 14 November 2000).]

[Greebe]

You'll also want to change the L2 cache latency. Right now it's set to 1:2 which will bomb out on you above 850 if not set to either 1:3 or 2:5 (if it will even do the latter). I'm guessing the your L2 chips are marked 2.9ns to make this assumption. Once this change is made I'd expect your upper limit to be above 900, maybe even over 950.

Also I'd suggest recheck you wiring. B4 and B17 are physically connected together within the Athlon PCB and if they were the problem then something else isn't right.

P.S. I have yet to see an Athlon run at an fsb of 133mHz on any system and you shouldn't expect above 110mHz fsb with your MB.

[Greebe]

Bummer, I've seen some Athlon 700's with 3.1 and 2.9ns L2's. My Athlon 500@850 has 3.1 ns L2's and run fine to 800 @ 1:2

DO NOT go above 1.9Vcccore!!!

Yes better cooling! (water cooling is great!

Also a copper spacer and Arctic Silver HS compound would help you out alot!

[lindberg]

Okay greebe, check this out! I even found a site where they'd run the FSB at 150 MHz (but that was a thunderbird, and the guy was a japanees who experimented with liquid nitrogen).
Strange with that B4 and B17 though, I also checked with an ohm-meter at the athlon and all the earlier mentioned GND actually were hooked togehter. But I also left out the B1 pin due to my board desing (when I cut out B4 the B1 went with it).
I've triple checked,even quadra checked my wiring and it seems ok. i compared with a picture of northwind GFD and they've seemed to leave out the B4 pin (and B17???).
Anyway it's working now so I don't now if I'll do further research in this, at the moment I'm just happy that the GFD works

(I think that a link to the chineese guy was posted in a reply in the link i posted )

[This message has been edited by lindberg (edited 14 November 2000).]

[This message has been edited by lindberg (edited 14 November 2000).]

[lindberg]

Anyway I got my Athlon 700 to run at 850@1.9V, and with setting the FSB to 103MHz I got 875MHz and memory at 137MHz...
quite a lot faster..
I would start at 914MHz but it froze when entered windows..
Now if I'd only get a quiet waterpump so I'd get my watercooling to run .
..or maybe underclock to 650 and get the FSB to run at 133, it would be a LOT faster then

[lindberg]

I just remembered that I haven't said thanx to you, greebe, so thank you for your help . I owe you one, because you were the one that warned me about Dr.Toms flaws in his schematic!
Without your help i probably wouldn't have survived the project with making my own GFD...

------------------
My system:

• Athlon 700@875 (8.5*103,memory @137)
• Majesty Processor cooler (sweet)
• 256 Mb Ram (133MHz)
• Asus K7V mb
• Matrox G400 (oc @ 150/200)
• wester 10.2Gb and seagate 6.5Gb (removable) hdd
• Aureal SQ1500 soundcard
• Logitech Force Feedback wheel (pretty cool)
• 300W atx high tower case
• Dual Majesty Exhaust fans (sweet silence... ),1*92mm exthaust + 1*120 in the front..
• 100 Mb External ZipDrive

My Homepage
I'll soon take my homemade watercooling in use (I'll put pics and info on my homepage in about a month...)