RMClock and AMD X2 Brisbane CPUs - an unstable combination?

[jrichrds]

RMClock v2.35 works great to undervolt my AMD X2 Brisbane CPUs (both G1 and G2 steppings) if I only use one p-state. But once I enable multiple p-states in the Performance-on-demand profile, it will randomly crash during the p-state changes.

After some research, it appears to affect a lot of Brisbane users, and has to do with the frequency and voltage changes not being well synchronized. The only rememdy I have come up with so far is to use voltages that are compatible with all p-states, which partially defeats the purpose of using RMClock.

So I'm just wondering if anyone has tinkered with the advanced settings to actually get RMClock to work reliably when undervolting.

 

[kotrtim]

Same here, it only works stabily for 1 p-state, i will use rmclock when i am trying to play games or doing intensive task on my laptop (turionX2 1.6GHz 90nm). Windows ca automatically adjust the freq according to the needs, no need to undervolt a desktop, the difference is negligible.

 

[zilexa]

This is an old topic but the problem effects even more people now. I have the AMD Athlon X2 5050e CPU (with 780G mobo, Gigabyte) and I have the exact same problem.

When I set RMClock to startup with Windows, once RMClock is started and the CPU goes idle, RMClock lowers the frequency/voltage and BANG! blue screen of death.
Even if I set the lowest voltage in the 0.9x something.

Only if you set 1 voltage for all P-states it's stable.

How come?
Anyone with knowledge of the advanced RMClock features might know what to try?

 

[RyanM]

Any news on this? It looks like RMClock still hasn't been updated since '08.

 

[robmurphy]

How much better is RMClock than CnQ?

I run a 4850E on my main machine. I have overclocked it to 2.8G, ht 224. CnQ brings the idle speed to 1.125 G, and the voltage down to 1.0 volt. I checked the power difference between the stock frequency of 2.5 G, idle 1.0 G and the over clocked settings and at most it was 1 watt.

What is the advantage of RMClock over CnQ. Does it undervolt better than using the BIOS?

Rob.

 

[aigomorla]

Originally posted by: robmurphy
How much better is RMClock than CnQ?

What is the advantage of RMClock over CnQ. Does it undervolt better than using the BIOS?

Rob.

That totally depends on your objective.

RMclock i tend to use more on my laptops then desktops.

How great is RMClock?

Well my laptop which has a stock voltage 1.25v after RMclock and testing, its downvolted to .975v.

That exchange allows my laptop to run longer, and cooler.

So is RMClock worth it? yes..

However on a desktop, you can just go into bios and adjust voltage manually below levels of CnQ after testing.

So would RMclock be worth it?
I dont think so.

 

[robmurphy]

I agree on the BIOS side.

I cant remember the stock voltage, but I did find if I wanted to run at the stock frequency the CPU would run fine on 0.05 to 0.1 volts less. CnQ would use the voltage set in the BIOS as its starting point.What I did find however, again, is that it made less that 1 watt difference to the overall system power consumption at idle.

The reason I settled on 2.8G, and I had had it stable at 3.0 G, was that at 2.8 G the ddr800 memory was running close to 800 meg, and on most other settings it was running at less than 800 meg. At stock the 4850E runs ddr800 at less that 800 meg, and as far as I was concerned memory bandwidth was important. 2.8 G increases idle power only very very slightly, and does give a usefull boost to performance.

At present typing this the system temp reports 30C, and the CPU core temp reports 22C. I do use a bigger heatsink that the one provided. The one used is one from a 89 - 90 W tdp S939 CPU.

Please bear in mind this is in a uATX case with 3 Hard drives, and HP's PSU from the original S939 PC. My original post is here: http://forums.anandtech.com/me...190905&highlight_key=y

The system has been runing, cool, very quiet, stable, and very easy on power for about 16 months now.

Rob.

 

[zilexa]

I'm back! Nice to see even RyanVM is interested.

Why undervolting a desktop? Simple: HTPC!

I have a small low height Silverstone HTPC under my TV. I tested undervolting with RMClock and CrystalCPUID in the summer when the temperature in my appartement rarely came under 24 degrees Celcius.

When undervolting, my CPU fan would go in it's lowest RPM state, even when I sat next to my pc with clean ears I couldn't hear anything.
That's very nice when watching movies, during silent scenes. Or when the tv is off, and I am silently busy, but the HTPC is running

Second, my pc uses less power.

Third, undervolting manually in the bios is useless because then the system will run at a low voltage and frequency all the time. I don't want that.
I want the lowest possible energy consumption 70% of the time, since the HTPC is always on running HFS (http file server), uTorrent, Filezilla Server as windows service... the CPU can run at 800MHz @ 0,75 volt... thats a lot lower then Cool'n'Quiet.


As a reference, please see this topic (Jos) with the same issues:
http://forum.rightmark.org/topic.cgi?id=6:1802

 

[Marty502]

Any reason why you're not trying with CrystalCPUID?

It does the same thing, it might work for you.

 

[aigomorla]

the question tho was using RMClock on a desktop.

Which i dont see the point in doing unless your board doesnt have bios overclocking.

 

[zilexa]

@ Marty502: As I've written, with CrystalCPUID it's the same issue although the BSOD's seem to be less random since they only accur during the power state transitions, wich still makes it impossible to use the htpc normally.

@aigomorla: I do not understand why anyone would want to undervolt a desktop using the BIOS?
undervolting in the bios means: fixed frequency of your CPU since the stock frequency requires more power than the lower frequency when undervolting.

As I explained, I want low frequency thus low power usage when not using the pc, and stock frequency, higher voltage when using the HTPC.
It's a waiste of electricity and I can hear my CPU fan when the HTPC is only functioning as fileserver and torrentdownloader. Perfectly good reason for using RMClock on not-laptop. Then I hear nothing and I am not waisting energy.