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View Full Version : PCIe Link Width stuck at 1x or 8x


LoneWolf121188
01-28-08, 04:00 PM
Sorry to cross-post, but I thought this would find better help in the nVidia section rather than GCRD now that I've established the problem.

I was running Flight Sim X on my MacBook Pro (running Vista) last weekend after doubling my RAM (4GB FTW!) and everything was going great. I noticed a HUGE increase in speed, and I was able to pull 25fps or so with most settings all the way up. Life was good.

Three days later, I boot back into Vista to do some more simming. Don't mess with anything, just load FSX after Vista finishes loading up. I run the exact same mission that I was doing before...and everything just grinds to a halt. I was getting literally <2 fps. WTF? I reboot, thinking its some random weirdness. Lo and behold, it does it again. The processor is throttling up to full speed correctly, and its plugged into the wall. Finally (with some help from thideras...thanks!), I establish that the PCIe Link Width is stuck at 1x. I try installing some driver OCing apps, hoping they might reset something that got screwed up in the driver, but nothing seems to help. After installing PowerStrip, it bumped up to 8x, but that still doesn't fix the problem (it needs to be at 16x). Any ideas?

I can't do a driver update as regular nVidia drivers don't work for the 8600GTM; only the Apple Boot Camp drivers will work. I could try reinstalling those, I suppose...

thideras
01-28-08, 04:11 PM
Did you try what I suggested? :eh?:

Jas
01-28-08, 04:33 PM
Force the frequency to 101?

thideras
01-28-08, 04:44 PM
Force the frequency to 101?It is a mac ;)

Jas
01-28-08, 04:53 PM
hehe, that'll learn me to read next time

LoneWolf121188
01-28-08, 08:03 PM
What, switching out the RAM? Yes, I took out one of the 2GB modules and it switched to 8x for one boot, then went back to 1x after I rebooted again. Its weird, every time I make a hardware change, it switches to 8x for one boot, then goes back to 1x. I sold the original modules...like I said, it was working fine up until this week. I can try to find someone in my dorm with a stock MBP and borrow their RAM...

Can you change the PCIe clock from windows? Clockgen, maybe? Does anyone know what PLL my mobo uses? The NB is an Intel GM965 and the SB is a 82801HBM (ICH8-ME)...so says CPU-Z 1.43. Both ClockGen and setFSB are having trouble getting my clock speeds.

I tried a driver update with a modded .inf file and I actually did see a small improvement in fps, but its still doing the 8x-1x thing.

LoneWolf121188
01-29-08, 05:59 PM
So I just found out that this isn't a windows-only problem. In the System Profiler in OS X, its also reporting 8x.

Charr
01-29-08, 07:12 PM
Can you access the BIOS/EFI?

LoneWolf121188
01-29-08, 11:21 PM
Can you access the BIOS/EFI?
Unfortunately no, AFAIK.

Evilsizer
01-29-08, 11:28 PM
well from reading this just to make sure
http://www.intel.com/products/chipsets/GM965/gm965_diagram.htm
you can do 16x pcie speed, first i thought it would only do 8x. the only other tricks that have fixed are as suggested for desktop boards.. up mch or pcie voltage/pcie speed increase. since your not sure about getting into the bios i would call apple up about it.. see what they say cause something in the bios isnt right..

VitasLoWang
04-07-08, 12:49 PM
Hey man you should solve it by setting PCIe frequency to 110MHz! It helped for me, although I don't have a clue why the hell is this happening :-] I have GeForce 8800GTS on Gigabyte 965P-S3.

LoneWolf121188
04-07-08, 02:59 PM
^^ As I said, I'm on a mac and don't have access to my BIOS or PLL. Anyway, I sent it to Apple and they replaced the mobo and now everything's working fine.