View Full Version : Odd clock speeds with 6600GT/AGP in Linux

01-22-05, 08:02 PM
I'm running Slackware 9.1 with the NVIDIA 6629 driver pack. My hardware specs:

Asus A7N8X-E Deluxe
Barton 3200+
Corsair PC3200 CL2 1GB
Antec Tru380 380W PSU
watercooling on CPU, northbridge, and GPU
Thermaltake copper ramsinks on GPU memory

I'm using the latest bleeding-edge CVS version of nvclock to check/change GPU and memory speeds. The 6600 series isn't officially supported, but if nothing else the speed reporting is accurate, AFAIK.

So here's what's happening:

Occasionally X will refuse to start because the driver complains that the external power connector is unplugged (even though it is plugged in, on its own wire and all). This only happens maybe 1 out of 10 X startups, but it was annoying so I added the NoPowerConnectorCheck directive to XF86Config. Unfortunately I think this may have been the first sign that something might be wrong with my card.

I was running some benchmarks and noticed that I was getting grossly aberrant data. The quickest and easiest benchmark I've been using is the Q3A timedemo, which when the card performs "correctly" clocks in at around 250fps. However, sometimes I would get scores as low as 50fps. Restarting X a few times would eventually return the 250fps score.

This was when I located nvclock and did some analysis. Looks like my card occasionally starts at an unbearably slow 100Mhz core, 600Mhz memory, and refuses to clock any higher in 3D mode. This is not correlated to failed X startups due to the power connector not being connected. Occasionally it starts at the correct 300/900, but then refuses to go higher in 3D mode (gets around 180fps). And on the rare occasion that it starts up properly, the 300/900 clicks up to the 500/900 and I get good scores.

Has anybody else seen this problem? Might it be a driver-related issue? I don't think it's heat related, since the core never gets over 45C, and the AGP bridge stays reasonably cool (I've got the Asus nForce2 chipset heatsink arctic silver epoxied to the AGP bridge on the card).

What's weird is that if the card starts up at the 100/600, and I use nvclock to force it to 550/1100, I still get really crappy scores (~116-130 range), but if the card starts correctly and I force it to 550/1100, I get fantastic scores (~280fps).

This whole situation has me completely stumped, and I'm praying that somebody out there has a magic incantation I can use to fix this problem, since I've voided the warranty on my card by modding it. No RMAs for me!!!

Any suggestions, even those that are completely off in left field, would be appreciated.

Daneel Olivaw
01-22-05, 08:21 PM
All my suggestions would involve running tests on a temporary windows installation, so as to put any Linux config-errors aside.

01-22-05, 08:36 PM
Yeah I've thought about that...but ugh I think i'll take that as a last resort...no spare hard drives lying around.

Also, if any of you are curious as to how I've got the rig set up, http://www.djskaven.com/rig has some pictures.

01-23-05, 01:01 PM
Hmm...no other suggestions?