Topic: Different voltage for windows and linux? oO; [0.5BTC bounty] (Read 2650 times)

AMD just hasn't made a driver that can do this, why? Because there isn't a gamer market for linux I am betting they didn't see the cost effectiveness of programming one for a market that is unlikely to use their product for anything other than academic/trasncoding in the first place.

Like I said before, just use RadeonBiosEditor under windows to set the values, THEN you can put it in a linux machine and have everything preclocked/tweaked requiring with no extra drivers or tweaking at all.

it's stable under linux, but not under windows.
Problem is that i can't get good speed stable under linux, only 870-880 is the maximum stable clock and stock voltage. Temperatures give room for a slight increase in voltage to get to more average result.

But most of all, i'm curious as to why, as isn't voltage forced by bios/hw.

I'm using LinuxCoin: So yes, included CCC but CCC lacks all overdrive features. AMDOverdriveCTRL cannot change voltage.

I think the question we need to be asking is this:
Are you having any trouble keeping the card stable while mining?  If no, then be happy that the voltage required is lower because it doesn't matter anyway.

Linux and Windows code passed to the card is going to be slightly different.  While Windows can see one thing from the same value Linux is given, Linux can see another and both will handle it differently.  The thing is, if both of them work with the same end result of not crashing and letting you do what you want to do, it shouldn't matter.
Now, if all you want to do is raise the voltage and temp because Windows had it that way, WTF?!  That's only going to server to burn-up your card with no advantage beyond making a space heater out of your computer.  Now, if it's not stable, we can fix that problem on its own.

With that said, did you actually download and install the ATI catalyst control center for Linux to your computer?  If so, try playing around with it.  I hear changing the values to their highest setting, exiting then coming back to change them again can sometimes result in setting a higher OC.  Otherwise, check out the files where ATI keeps its configuration data and try modifying them directly with the values you desire.

ATI's own catalyst on both, latest i believe on both. no 3rd party apps messing.

On linux i can't raise the voltage even.

The differences just have to do with different software.  The card starts with certain defaults defined in the BIOS - "something" is changing them after you get started up.

If you've got a third party card and install third party tools (MSI AfterBurner, for example) then that will most certainly have a different "default" than Catalyst 11.5 on Linux.  There is also chance you're also using a branded driver - Dell, Lenovo, etc will supply a Catalyst driver that is "tailored" to their computers rather than the vanilla Catalyst driver.

Catalyst 11.5 and Catalyst 11.6 under Linux even sometimes show different values on some cards.

The 69xx series cards are some of the newest cards with totally different architectures.  I've had some issues with 6950 and 6970 series all over the board - one of my 6950s didn't even have a working fan control in Linux.  Setting it to "auto" wouldn't start the fan until the card was over 85C.... which is far too late to start trying to cool it....

AMD/ATI's drivers in Linux have always sucked.  Always.  Realistically, their drivers aren't much higher quality in Windows, either.

Make sure you're using Catalyst 11.6 and SDK 2.4 with the 69xx series.

not really, they are kinda besides the point.

The different values under linux & windows are in question, driver issues, or just dif between linux & windows drivers?

I can't control power even under linux, i can't get it to 1.2 like under windows the default is 1.2! :O

That's the thing, why different defaults under linux & windows?

Did any of that help?

LegitBit beat me to it.

It's a bit of a pain, but flashing is really the best way to go.  No need to reset the values (+lazy) and it can be more stable.

How could it be more stable?

You'll notice that normally a card is set with a widely varying range of values.  Rapidly switching between these values can cause issues - lock ups, hangs, driver crashes, etc.

In normal use, you're less likely to notice (and you're less likely to trigger the cycles rapidly).  For example, you would start a game at which point it would go through the different profiles until it reached peak performance (or switch directly to it).  It would stay in this mode for a decent amount of time and then eventually go backward through the profiles when the game ended.

In mining, you might notice you rapidly flip between these profiles when things like network connectivity get in the way.  Your card will go from 99% GPU usage at the highest performance profile down to the lowest settings and then immediately back up in a very, very short amount of time.  Some cards don't handle this very well, and anyone that has repeatedly locked up a card starting/restarting different miners or those that have tried to set aticonfig/AMDOverDriveCtrl values while a miner is running can attest to the hair-pulling it causes.

Again, some cards can handle all the up-and-down mode switching without issue.  in b4 "I do that all the time!1111"

Also there are a few command-line utilities in Linux.. here is a good reference: http://forum.bitcoin.org/index.php?topic=10228.0

You can use windows to flash the bios with a higher voltage using Radeon Bios Editor.

http://www.techpowerup.com/rbe/

After writing the new voltage value, the card should always boot with those settings no matter what system it is put into.

I got a HD6950 which when on windows had 1.2 coreclock and temps was ridiculously high (upto 90C!), i put it into linux and voltage is 1.1 and i cannot raise this.

The card is only stable (24/7 stable) to around 885Mhz on stock voltage, and there is lots of room temp wise now, running at max 67C.

Also core clock was 850 on windows, and 800 on linux by default oO;

So how can i increase the voltage?

EDIT: CCC does not have the +20% power thing, or any performance settings under linux. Am using LinuxCoin.