dual monitors on 4850 & Cat 8.7 Vista x64 - problem

[MadMan007]

So I just started today on a BIOS-flashing adventure using RBE. My Powercolor card came with the 'low' clock setting at 500Core/975mem which is not very power-playish but a lot of the early 4850s came like that. So I made various BIOS files with RBE with lower idle clocks. Flashed and it seemed ok so I decided to update Cats while I was at it. I'd read the long thread on xtremesystems '700MHz core smashed on 4850' to figure out RBE and finally got the settings to apply and verified with GPU-Z. I also read that some people were having flickering issues on secondary monitors with beta 8.7s and reverted to 8.6s. Well, I decided the release 8.7s should be ok and did a full uninstall with drivercleaner, but it seems they might not be I didn't test extensively with the 8.6s though.

Now the odd part is I tried a lot of core/mem combinations and some seemed better than others in terms of the flickering and it wasn't just that more was better. 250/500 was better than 400/600 and 160/500 was in between for example and some clocks made half the screen flicker black when resizing a window on the primary window. Voltage didn't seem to have a logical effect. So now I'm at 500/750 for the 'low' settings which is about where I started :bang head and the flickering is very minor, also a little wierd is that just resizing a window on the main monitor back and forth with Aero can kick the GPU in to full performance mode.

So does anyone else have dual monitors on a 4850 and what's your experience?

[MadMan007]

I reverted back to regular (non-hotfix) 8.6s and the problem is still there with the same exact clock speeds. Perhaps I'd never noticed it before or perhaps there's something going slightly wrong with my card :( I hope not I haven't had it very long. I may try the hotfix 8.6s but given that the problem arises with 8.7s and I had problems getting the Hotfix drivers to work correctly once before I probably won't.

Someone else must be running dual monitors on a 4850?

[jason4207]

I've modded my BIOS for 160/500 in 2D, but I only have 1 monitor atm.

[deathman20]

Hmmm i'll have to fiddle around with it. I haven't tried playing with clocks much on the low side but I'll have to try a lower idle clock and see if it works with mine. I had no issues with CF'ed 4850's in general with 8.7's and dual monitor, but at stock clocks of course.

[MadMan007]

I have a hunch that it has to do with memory clock transitions after I looked at the clock settings in a bunch of the BIOSes at techpowerup and noticed some petterns and also remembering that my original BIOS had reduced core but the same high 3D memory clocks for lower power settings. It also 'feels' like a memory issue to me since it consists of either subtle lines or parts of the screen flashing black. So later I'm going to try a BIOS with reduced core clocks but 3D-high mem clocks across the board.

deathman - do both your memory and core clocks change or just core? Please look in GPU-Z sensors tab while resizing a Vista Aero window, moving the corner in and out diagionally for a few seconds usually is enough.

It still seems lame that simply resizing windows in Vista Aero causes clocks to go to max 3D :rolleyes:

[deathman20]

I have a hunch that it has to do with memory clock transitions after I looked at the clock settings in a bunch of the BIOSes at techpowerup and noticed some petterns and also remembering that my original BIOS had reduced core but the same high 3D memory clocks for lower power settings. It also 'feels' like a memory issue to me since it consists of either subtle lines or parts of the screen flashing black. So later I'm going to try a BIOS with reduced core clocks but 3D-high mem clocks across the board.

deathman - do both your memory and core clocks change or just core? Please look in GPU-Z sensors tab while resizing a Vista Aero window, moving the corner in and out diagionally for a few seconds usually is enough.

It still seems lame that simply resizing windows in Vista Aero causes clocks to go to max 3D :rolleyes:


Hmmm I'll have to look at it but from what I noticed Aero didn't activate my 3D clocks for my GPU. With that it as well seemed only to use maybe, 1-2% of GPU power at 500/750Mhz (default 2D/LP) clocks. I'll take a gander at it as well play with my settings a but more and crank down the core a bit. Does anyone know if you can drop the 2D voltage and by how much?

[jason4207]

I did notice that Vista Dream Scene locked my clocks at 625/1000 even though that wasn't one of my presets. It must have been using one of the other 'Clock Info' boxes that I didn't set. It stayed locked even if I opened up ATI Tool.

As for min 2D voltage, I have mine set at 0.94, but my volt mods bring that up a bit. W/ my VR pulled out I was getting artifacts all over the screen while scrolling, so 0.94 is a bit low unless you're also using hard-mods. I think 0.99 will probably work. Even if you set 0.94 you should still be able to boot.

[deathman20]

Well tried it out.... Quiet intresting results. I just used AMD GPU Clock Tool to test it out and downclock my cards. As by doing so the fan wasn't running at my 45% base speed, was down to actually 0% according to the thing but was more or less 15-20% is my guess.

Anyways while playing noticed something. Going to show the results in the following order. Clock Speed/Window Movement GPU %/Window Resizing GPU % This is of course with Aero on and 2 montiors.
500/750 - 2% - 16%
300/750 - 4% - 30%
160/500 - 7% - 61%

So while the clock speed goes down, you can definatly notice the GPU is taking more of the load with the Aero interface. But as well by doing such, really how benificial is it to run such a low clock speed if its going to eat up that power as well? I know its not like your going to keep the GPU pegged at that the whole time but be intresting to see if its actually more energy efficient to keep it at its rated speed vs a lower one when playing with window resizing.

BTW Zero glitches/artifacts/etc with it at 160/500 with both monitors in use and doing window resizing on both of them. Second monitor is only a 1024x768, main is 1920x1200. GPU temp got upwars to 60-65C doing test so heats not a major factor.

[MadMan007]

FIXED

Making it so the memory speed didn't cycle, just like the original BIOS whose powerplay states were 500/993(=975 since mem goes in 25MHz steps and same as mem speed as full speed state), fixed the problem. So now I have 250 and 500 for the low and mid power states on core, and 1000 memory for all.

Perhaps the usage has to do with my weak CPU, currently running a backup rig which is a Celeron e1200 while waiting for an RMA. It does hit the mid power state often enough but goes to the full state too, Vista's CPU usage gadget shows CPU going over 60-70% sometimes.

[deathman20]

Your memory doesn't cycle in idle mode to 750? Weird. I mean I have 2 powercolor's and mine have on both of the bios's that I've used. Originals to the card and updated bios's for the cards (no modified changes on them yet).

[MadMan007]

It may have, I didn't run GPU-Z *all* the time. I kind of remember memory going down in CCC though but I can't be sure. Maybe 750MHz is like the minimum to prevent the dual-screen problem, I guess I could try a BIOS with that. What's the updated BIOS from, techpowerup? If you could extract it with GPU-Z then take a screenie of the settings in RBE that would be cool :) Maybe I should just go back to the original BIOS :p you said you never saw a problem on your second monitor right?

The only thing holding me back from trying tons of BIOSes is that I use a floppy for it but it's not normally in my system which means I have plug that in, I don't trust Winflash and I can't seem to get a USB DOS boot drive working :(