6800 + O/C'ing FSB = artifacting?!?

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Cody8417

Limp Gawd
Joined
Jan 15, 2004
Messages
203
This is a strange problem i'm having with 3 different 6800nu's (2 bfg's, and 1 pny) on both an Abit KV8-Pro and an Asus K8N-E Deluxe.

Whenever i overclock the FSB of the CPU past 220ish, i start get texture flashing in games, regardless of whether or not the GPU is overclocked and AGP/PCI locks are enabled.

Furthermore, it happens even when I have it set up so that the DDR3200 stays at 200mhz (400 effective); meaning that the only thing going up is in fact the fsb.

It happens regardless of gpu and mobo chipset driver version.

I've also played around with agp, vcore, and vdimm voltages. I cannot seem to find a solution.

Does anyone have any idea what might be causing this or a possible work around?
 
its a thermaltake silent purepower 420w.

Before I dabbled with the 6800's, i had a 9700np and then a 9800p and neither displayed artifacting when o/c'ing the fsb (just for reference if it helps) (and yes i did format before switching to the 6800)

I don't really think its the psu although i guess its possible.
 
Yes, i've noticed that my 6800 Ultra will start to artifact in Doom III when I get my FSB above 245 Mhz.

I can usally see it on the weapons I'm holding (or my hands).
It may take a few minutes of playing to start seeing it.

I don't know why it does that.

My motherbord is a K8N Neo Plat. Anyhows 244 FSB is quite respetable so that's where it's at now (10 x 244). My CPU is an A64 3400+ Clawhammer.
 
ha, thats more like rubbing it in then helping me here, i can't even hit 220 really :\
 
It might be that at a certain FSB speed, the AGP speed lock breaks.

AGP normally runs at 66mhz.

That's just a theory.
 
i thought that too but i've tried fooling around with the ntune utility for nforce mobos and making sure its set at 66, so that doesn't seem to be the problem
 
Perhaps a voltage issue?

May be at a certain FSB, the AGP gets less juice ?

I'm grabbing at straws here :p
 
heh thanks for trying, like i said, i've fiddled with voltage all the way up to 1.7 for the agp.
 
well just for you guy's information, my fsb on my crappy board which doesn't have a pci lock, but do have an agp lock, is 277mhz, the only good thing i got out of this board is the fsb overclock, and a tiny 220mhz on the cpu.. GRRR and i am running a 6800ultra too.


and check your 5v rail.. because i think the fsb uses the 5v....
 
Try setting the AGP/PCI clock to 67 MHz or else the lock won't function correctly with older bios versions on the MSI K8N Neo2. I think they have fixed this with bios v1.4.

Edit:
I guess I'm a little tired, you aren't using the MSI K8N Neo2 :rolleyes:
But you could try setting the clock to 67 MHz anyway, it might be a NF3 thing.
 
I had some minor artifacting and some slowdowns that happened when I overclocked my Lanparty UT 250 with my 6800. I turned off fastwrites and it fixed everything. Fastwrites has serious effects in these newboards, probably because of HTT and LDT since the description of fastwrites claims that info gets sent directly to the cpu first instead of the memory. So with the new HTT and LDT technology, and the old fastwrite tech. there might be some sort of issues going on? That's my theory anyway.

Anyone with 754/939 boards and a 6800, try disabling fastwrites and see if it does anything at all: improve performance, decrease stuttering/memory loading when you get to new areas of games, gets rid of artifacting, allows more video card overclocking without artifcating, and if it gets rid of this FSB specific artifcating issue
 
Happy new year guys!

uh shoulda mentioned that i've tried fooling with fastwrites to no avail heh, seems like its a 6800 prob of some sort :\
 
bump for a solution someday lol

tried setting the agp lock to 67 and while that does also lock the agp bus at 67, it does not solve the artifacting when the fsb goes around 225 and up
 
It doesn't solve it for me either.

Something goes a little haywire when my FSB goes up too high (above 246 FSB). We'll find out one day.
 
fwiw i'm on a neo2 plat (v1.4 bios) with a bfg 6800OC and i dont experience this problem that your describing. i'm at 230 fsb (but i lowered my HTT multiplier down to 4x)

have you tried lowering your HTT multi?
 
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