Hi all.
I'm having a problem with my PCI-E link been at 8x or lower when its a full 16x board supposedly (not SLI)
Its a Palit 9600GT 512mb with a Core/Shader/Mem of 650/1625/950(1900 effective).
My pci-e link speed sometimes fluctuates too, not while i'm using it, but after a reboot or two it changes.
It might be all well and good at 16x at some time, then it will drop to 8x and a popular one at the moment is 1x.
Obviously the performace difference between 8x and 16x is negligible if at all noticeable even on these more recent cards.
However, 1x as you can imagine is crippling, my framerates literally drop to under 50%.
Another thing that happens is my motherboard sometimes (not all the time, maybe every few attempts) emits a series of bleeps when I try to start up the system.
My motherboard is an 'MSI K9N Neo V3'. It therefore uses an AMI bios. I have located a site where I could reference the bleep codes and it (one short followed by 8)
points to a 'Cannot write to frame-buffer' problem. From what i've looked at this either means a graphics card problem (damn, got it of ebay), or the motherboard.
The latter I can send back as its not the best board anyway. Oh, also there was nothing on the screen during the bleeps, probably an obvious fact as it wasn't post-ing at all.
I'm wondering if its got anything to do with the fact that the card is PCI-E 2.0 and the board is natively PCI-E 1.0. I know the cards and backwards compatible,
but all the same, the mainboard might have compatibility issues that I'm not aware of. I tried replacing RAM (OCZ DDR-800 platinum rev. 2) just out of curiosity but no fix there.
I then tried the graphics card in a friends Intel mainboard (775i65gz I believe) which is also just a PCI-E 1.0 board, but it boots up with no problems at all.
Also the PCI-E 16x bus works at the full 16x link speed. So I keep saying to myself that it cannot be the graphics card, even though those bios bleeps are very convincing.
I have yet to change PSU although it should be quite sufficient giving out 30amps across the 12v rail and having a rating of 550w. As the 9600GT geberally speaking needs a min of 26 this should be fine.
I'll try this anyway.
To summarize then, and make it a bit easier to comprehend...
...What I have tried all with no avail:
- Flashed the bios to latest release
- Re-flashed the bios to an earlier release (yeah, lol)
- Cleared the cmos more times than I can remember
- Changed bios settings...that should do for the bios...
- Reseated graphics card and other components like RAM
- Swapped PSU's own PCI-E power cable for a molex-to-6pin PCI-E converter
- Re-installed VGA drivers fully and cleanly including nforce drivers, well I put WinXP back on again fresh, so this aint the problem
- Looked on the 9600GT card for any obvious signs of defent (missing/damaged components, lent over capacitors, broken off resistors etc)
All that and still no luck.
The only thing that did give me the slightest bit of hope was when I used the friends rig to test the card, in which case the PC booted perfectly, and the link speed remained at 16x after several re-boots.
The PSU wierdly enough is the same as the one I have in my machine, rated at 550W and 30amps on the 12v rail to name a couple of specs.
So i'm thinking after all this that the most likely cause is a dodgy motherboard, at least dodgy in a compatibility-sense with the whole PCI-E 2.0 thing.
I was reading the specs of the PCI-Express 2.0 standard, and it seems that it supports a new features known as 'dynamic link scaling', intelligently adjusting the bus width depending on work load I guess.
However I'm not sure whether this will even take effect without a PCI-Express 2.0 motherboard, or with current drivers/BIOS revisions etc.
But could this be the graphics card not negotiating with the system bus properly and then giving the dodgy bleeps and knocking the link speed down to 8x or 1x?
I will see if the bleeps coincide with the changes in link speed to make doubly sure.
As you can see, I usually type a lot, lol. No stranger to PC's here or modding/enthusiast activities, but this one is a mystery, and a nightmare too!
I have a 'Gigabyte GA-770-DS3' on the way for next week, which natively supports the new PCI-E standard or v2, so i'll see if that makes any difference. Should be more 'compatible' surely, and if you ask me Gigabyte rock lol.
Anyone? Help would be very much appreciated. Topics on the matter seem very scare at present.
~Phoenix
