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View Full Version : High FSB fix for 9500/9700



Roop
02-02-2003, 09:54 AM
Myself and many other members of different overclocking forums around the world have found that the 9500/9700 don't run at high FSB speeds. This really sucks as the cards do cost alot and it was possible to reach a high FSB before the card was installed. Obviously the card is to blame here.

Whats wrong? Heat. The heatsink on the 9500/9700 is mounted in a way that is just good enough to run the card at stock AGP bus with a little overclocking on the GPU. That's fine and dandy for your average user who doesn't know what the FSB is but not for an overclocker. The GPU gets too hot and can't run at higher FSB (AGP) busses. You have two options to fix this, a) better cooling or b) a locked AGP bus.

The only boards that have locked AGP buses on the AMD platform are Nforce 2 based boards. Locking your AGP bus will allow any FSB without effecting the card itself. If you have a VIA based motherboard like myself, you don't have this option and will have to opt for better cooling if you want to push the card.

Better cooling. Buy a better heatsink? nah. Heatpipe passive cooling? nah. Those don't perform good. My FSB used to max out at 170mhz (68mhz AGP)) before. Right now i'm at 190mhz (76mhz AGP) and there still seems to be room for improvement.

Here's what I did: took the stock HSF off and cleaned the thermal interface material. i used arctic silver 3 and i also removed the shim. i stacked another fan onto of the stock fan. the fan i used was a 60mmx10mm fan. it's the one off of the stock AMD Athlon XP heatsink. I also mounted another AMD fan on the top of the card blowing directly onto the top of the GPU and the top ram modules. I used the little plastic deal off of the AMD heatsink to keep the fan slightly above the card.

the results are amazing.

before my mod:
max FSB 170mhz - would start to stutter after 5 mins of BF1942.
temp on the back of the GPU at idle: 55°C
temp at load 62°C

after my mod
current FSB 190mhz - will probably go higher, haven't tried yet
idle temp directly at the GPU core - 45°C
max temp at the GPU core - 50°C

all readings were done at +/- 2°C, 25°C ambient


well there you have it. The stock cooling is fine for a stock bus. If you want a high FSB you now know what to do. have at it!

Liquid3D
02-02-2003, 10:19 AM
It's amazing you bring this up. I was just overclocking my FSB, (running mem bechmarks specifically) and couldn't get above 219FSB, because my AGP is effectively running 95MHz, I'm not sure what percentage of an overclock that is to the AGP bus itself, but it's obviously too high. I have a GF4 Ti4400 so unlike the 9700 I surmize that's the reason I'm able to get as high as I did. And I have been as high as 221FSB. To me that's pretty good seeing as I'm running 1024MB of PC3500, and was told by a rep, my memory controller would only run one 512MB stick at a time.

Reason I'm replying is I should have my hands on a Tyan Tachyon G9700 Pro to demo by weeks end, and if I can't get above 221FSB now what's going to happen with that card? I'm waiting for Epox to announce they've made the VDD mod to their 8RDa+ boards as has been reported, and then hope to acquire one. I've also heard good things about Leadtek K7NCR18D-Pro nForce2 board.

I also wanted to suggest WPcredit, wouldn't that ameliorate you AGP worries? It does effect the AGP bus doesn't it?

Shuki
02-02-2003, 01:08 PM
Originally posted by Roop
i stacked another fan onto of the stock fan.

so you have two fans stacked right on top of each other? or you mean you removed the stock fan and replaced it with another fan?

Shuki
02-03-2003, 03:40 AM
followed your lead Roop and did in fact allow me to go up from 180 fsb to a 190 fsb :D 195 still ain't happening but 190 beats 180 :) Removed shim, used as3 and used that stock amd hsf fan in place of stock ATI fan. And roop, thanks for starting this thread!

TheDude
02-03-2003, 05:44 AM
Be careful with the AS3 guys...seen many posts where this has killed cards when it gets on places where it shouldn't. :D

Great job Roop! :toast:

I'm gonna give it a try also...currently stuck at 180, but my AGP is locked so I don't know if this is my problem.

eclypse
02-03-2003, 06:21 AM
You wana take that shim off easy, then stick her in a anti-static bag and put her in the freezer for like an hour or so.. Use a razor blade and "TAKE YOUR TIME" slip the razor blade under a high corner and very carefully lift up and it should start to bend that edge up or the whole thing will just pop off.. Go under another corner of the shim on the other side if need be.. just ofcourse make sure ya dont cut up or slip and cut into the PCB.

Ya can reuse the same retail heatsink if ya aint got nothing on hand but plan on either buying something else for it or makin one for better results.

I did this and before i couldnt run any higher then 185FSB on a Abit KX7-333 Raid then after takin the shim off and makin my own custom fit heatsink wtih about 3 inch long fins and using a powerfull quiet squirle fan from Radio shack (Blower fan) she went to 200FSB easy and on top of that i overclocked the cards core to 410Mhz no problem.. Before i could only do 330-340 before she would lock up.

]JR[
02-03-2003, 08:35 AM
Dunno about freezers and esd baggies the shim on mine virtually fell off...

]JR[

Shuki
02-03-2003, 09:07 AM
my shim was on there ROCK solid!! after an hour on freeze mode, a pair of needle nose pliers on one corner and *plop* popped right off :D Not recommended but it worked heh