E6600 Overclocking vs 3DMark06! Strange results

[DougMcDonald]

Hi Guys,

Quick question here. I have been running my 6600 at 360x9 for a while and it has been staying nice and stable. I can get a >11000 score on 3dmark06 with a slight GPU overclock. Which I was happy with until recently.

I decided that now my thermal paste has settled down a bit, I might try to push 370x9 or up to 380 perhaps. Whilst this seems to work fine when i reduce the ram to 5-5-5-18 the performance in 3dmark06 goes completely mental.

At 360x9 The very start bit of the first test is about 75 fps but when i change to 365x9 the start sequence will drop to 17-25 fps.

This seems very strange considering I was expecting a small increase rather than a huge decrease in benchmarking tools!!

The same occurs if i go to 370x9 or 375x9 etc etc, it seems that 360 is the max I can currently reach without crippling something. Any info would be greatly appreciated.

Has anyone else seen this type of problem or know what ist could be caused by? I'm completely stumped!

[Clunk]

Could just be a "FSB Hole", from around 360FSB to 400FSB there are points where things go pear shaped, just try slightly higher.

Or alternatively, you can drop the Multi to 8x and bypass these points.

[DougMcDonald]

I will push it a bit higher and see what happens!!

Out of interest, presumably if i drop the multi to 8x id need to hit 400 fsb to reach the 3.2 type speeds im currently getting from 360x9.

If I want to go higher, I'd obviously need to go above 400 is there a chance I could run into problems with the ram running at greater than 400 fsb? its only pc6400.

[Clunk]

Just keep the RAM at 1:1 while you are doing this. What RAM is it?

Your P5B should be good for around 500FSB if the rest of your system is up to it, you may need to add some extra voltage to the NB, but its nothing to worry about

[DougMcDonald]

The RAM is set to 1:1 so that shouldn't be a problem.

It's 2GB of Geil PC6400

I think my spec should be in my profile if any other bits need checking. It's a fairly new system though so I would be surprised if it couldn't cope.

Will give it a go after updating HL2 install (few hours :s )

[Clunk]

They updated the forums last week, so you need to re-enter your info in the My System bit

[DougMcDonald]

Ah yeah :]

Stupid me, I'll sort it out when i get a sec

[DougMcDonald]

Hmm, i have tried some of the suggestions and haven't seemed to resolve the problem.

I have however established why there is such a drop in gfx performance.

It seems too reduce my pci-e bus width to 1x when i put the fsb above 360.

Anyone got any ideas what would cause this? does it imply a power issue? can I solve it by putting up the voltages in certain areas? if so, what should i tweak? southbridge?

[roorooroo]

I tried OC'ing my system (Cpu and GPU) a couple of weeks ago..all went fine..tried 3dmark06 and my score went down about 100 marks..weird.

[DougMcDonald]

I can certainly get a performance increase from cpu and gpu tweaking 2000 or so 3dmark06 points, but its this limiting pci-e link width to 1x which is causing such nasty issues.

Hopefully someone can point me in the right direction to top 360fsb with 16x width....hint hint...!!

[Clunk]

Change the PCI-E frequency from auto to 110, save and exit, boot to windows, check with cpu-z and see what your pci=e link width is, and it should be back to 16x. You can go back to the bios and change it to 100 and leave it there.

[DougMcDonald]

Cheers for the suggestion Clunk, unfortauntely the link width still says at 1x when on 110 frequency.

Any other ideas?

[Clunk]

115

You just need to give it a shove...some people, it shifts by doing 100, some 120 etc..it will shift, you may need to clear the cmos as well, and then do it.

Make sure you change it back to 100 afterwards though.

[DougMcDonald]

Gotcha, well 120 wasnt working, ill keep going till i kicks back in.

I've removed my ati tool gpu overclock for the time being incase that was affecting it :]

[DougMcDonald]

Hmm, I've made some more progress on this one.

Pusing from 350 - 360 i can keep it at 100 pci-e frequency and acheive 16x

When i hit 370, it reverts to 1x link width and pushing the frequency to 110 allowed it back up to 16x link width.
However, when i put it back to 100 frequency, it reverts back to 1x width.

Is it a problem to run the pci-e frequency at 110 perminently?