Can I put an idle CnQ AMD CPU into HLT state as older ones?

New to PC silencing? Read & post your questions here. Dedicated to rosy_toes.

Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee

Post Reply
gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Can I put an idle CnQ AMD CPU into HLT state as older ones?

Post by gamebox » Mon Sep 22, 2014 10:18 am

Hello all. :)

I'm a silent/energy-efficient computer lover. Didn't know that there was a place for people like me until I found this website. :)

I have a question regarding my system. It's an nForce4 based HTPC (or at least I prefer considering it one), with Athlon64 3500+, Radeon HD 4350 (chosen for it's superb efficiency and to offload video decoding from CPU), 1GB dual-channel DDR400 RAM (soon twice as much), and 22in FULL-HD LED display. I've already enabled Cool'n'Quiet on a CPU together with fan PWM control in BIOS and that works fine. The processor is a "second generation Athlon64" (as I call it), Winchester core (I think), with about 67W TDP. I've been asking myself are those old software-cooling tools like CPUIdle and the like, meant for older non-CnQ Athlons, still operable on newer systems like mine? Will they put my CPU to HLT (STOP) state when load is very low, for the sake of further reducing power consumption, PSU load and core temperatures - effectively adding something like the "fourth" CPU power state (current CnQ offers three)?

There are also two more things I don't understand - I've set CPU-fan's PWM threshold to about 40 degrees, meaning that it doesn't turn on until temperature reaches that point. It works as planned - the fan spins on power-up, then stops, and starts spinning again when system slowly heats-up from room temperature and reaches the temperature threshold on load. But, from that point on, no matter how low the CPU temperature goes, the fan keeps spinning at the lowest speed. Why is that happening? Also, if I boot to DOS to perform some task like ghost file creation when the computer is still cold and CPU-fan is stopped, it will NOT turn on at all when necessary, risking CPU-overheating! I've found that out once after I rebooted after working in DOS and seeing CPU-fan spinning like mad (at about 4500 rpm) - the computer even switched off itself on the first attempt, probably to protect the dangerously hot CPU. Why is that happening - isn't BIOS supposed to control fan speed, that shouldn't have anything to do with OS or (CnQ) drivers?

Thanks in advance, folks. :)

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by Vicotnik » Mon Sep 22, 2014 11:12 am

Hello and welcome to SPCR. :)

First I must say that if you really care about low power consumption, consider getting a more modern system for a HTPC. Something like Baytrail perhaps. An nForce4 system with an Athlon64 3500+ and Radeon HD 4350 is a power hog, relatively speaking.

Apart from making sure CnQ is enabled I don't think you can do much more to lower power consumption, besides underclocking and undervolting if your motherboard supports it. But I might be wrong; it was a great while since I messed around with nForce4. :)

Regarding the CPU fan I think the reason for the fan stopping might be that it doesn't get enough voltage for it to spin. It was never meant to stop, just spin slowly. CnQ functions doesn't touch fan speed, only reduces clock frequency and voltage to the CPU (which in turn might alter the fan speed if the fan is temperature controlled). That the fan stops indicates that something isn't right, perhaps and old fan with worn out bearings?

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Mon Sep 22, 2014 11:28 am

Thanks for reply Vicotnik. :)

The fan is temperature controlled, and BIOS has a parameter to define the temperature where it would start spinning. So, it is not a flaw - it is meant to be stopped until CPU heats up to a defined level. It just doesn't stop again when the CPU returns below that temperature threshold.

Buying another configuration is above my current plans (when it comes to money of course). Why would an Athlon 64 based system be a "power hog" as you reffer? The CPU idle consumption is about 29W, the GPU consumes 7.7W idle/9.9W decoding HD, the current PSU is rated at only 350W and comes from my old machine, where it was running Duron1200 @ 55W and GeForce4 GPU.

I'm just asking myself if I could put the CPU to HLT on very low load, to additionaly reduce it's consumption and temperature (besides 29 Watts at lowest level in CnQ and below regular 30 odd degrees of temperature on idle), as well as to reduce load on PSU (although it is not dangerously overloaded and runs reasonably cool).

washu
Posts: 571
Joined: Thu Nov 19, 2009 10:20 am
Location: Ottawa

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by washu » Mon Sep 22, 2014 11:43 am

Unless you are running Win98 or older, utilities like CPUIdle are useless. All modern OSes execute HLT automatically when appropriate.

washu
Posts: 571
Joined: Thu Nov 19, 2009 10:20 am
Location: Ottawa

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by washu » Mon Sep 22, 2014 7:43 pm

gamebox wrote:Why would an Athlon 64 based system be a "power hog" as you reffer? The CPU idle consumption is about 29W, the GPU consumes 7.7W idle/9.9W decoding HD,
A modern Haswell or Baytrail CPU can potentially idle at under 1W and that includes the GPU. Even when running full bore, all but highest end or overclocked Haswells will use less power than your AMD chip doing the same. The onboard GPU of Haswell or Baytrail have full HD decoding, eliminating the need for a separate GPU and its power use.
the current PSU is rated at only 350W and comes from my old machine, where it was running Duron1200 @ 55W and GeForce4 GPU.
A PSU from that era is going to be well under 80% efficient if you are lucky, more likely under 70%. You are wasting an extra ~30% on top of your already inefficient system.

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Mon Sep 22, 2014 9:10 pm

@washu: I'm running XP Pro 32bit. Are you sure OS-es above Win98 use HLT on CPU automatically? I ask because I installed XP on another machine too (it is my old Abit mobo, Via KT133 based, now with Athlon XP 2400 instead of Duron 1200), and the situation did (considerably) change when I added the GiveIO dll library from an ancient VCool software to the system and then used VCool to check temperatures - the CPU ended being one degree cooler than the system so it was almost completely off on no load, and PSU was also blowing almost completely cold air (GPU is very undemanding-Ati rage 128 pro). To add to that, I also don't remember seeing the temperatures on my old Duron oscillate more than 2-3 degrees in XP on full load vs no load, when I didn't use any kind of software cooling.

Regarding only moderate efficiency of Athlon64 - I know cutting edge technologies give outstanding energy economy, but they are out of the question for me at the moment because of many reasons (money, many old components at hand still perfectly usable (4 IDE optical devices and 3 IDE HDDs, reliable (IDE only) PSU, my desire to use high-performance single core CPU for a while longer, etc etc). My goal is not to reach total perfection, just to perfect my existing setup.

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by Vicotnik » Mon Sep 22, 2014 9:54 pm

gamebox wrote:The fan is temperature controlled, and BIOS has a parameter to define the temperature where it would start spinning. So, it is not a flaw - it is meant to be stopped until CPU heats up to a defined level. It just doesn't stop again when the CPU returns below that temperature threshold.
As far as I know no motherboard has that feature, even today, to stop the CPU fan completely. Well, maybe some fancy modern Asus board but then the case fans I think. Usually you have the option to set a target temperature that the fan will try to keep the CPU at, or a temperature where the fan will hit max speed or something like that. Stopping the fan is a bit complicated, since it might be hard starting it again, usually it needs a burst of higher voltage to make sure it really starts etc. Also, most CPUs, especially from the nForce4 days need airflow at all times, even when idle. So it's not a desired feature in most cases. I think that PWM threshold you set in the BIOS means something else than when the fan should start.
What motherboard do you have? The manual might explain the setting.

And I understand and support using old equipment. It's just that at some point the cost of electricity will be higher than the cost of a new system. Add to that the added benefit of lower noise etc. It's worth keeping an eye on real power consumption vs. the cost of a low power system.
Heck, I think I'd rather use a Raspberry Pi with an external USB HDD than an nForce4 system with a number of smaller HDDs as a HTPC. ;)

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Tue Sep 23, 2014 5:35 am

@Vicotnik: The mobo is low-end, Winfast (Foxconn) K8CK804A05-6LRS, one of the first generation mobos with fan regulation - the CPU fan has 3 wires and no built-in regulating electronics as far as I know - the board does it instead. The mobo has four options in BIOS for this - Start PWM value (0-127): I use 127 meaning the fan starts at lowest possible speed (1300RPM), Slope PWM value: 8 PWM/C (steps of speed increase with temperature), PWM full-on temp: 56 (fan goes max rev when CPU reaches this temperature (which pretty much never happens)), and PWM start temp: 40 (that's the threshold at which the stopped fan starts spinning).

The electricity price in my country is not that high, and I already use a number of affordable energy-saving technologies (CFLs, induction cooker, high-efficiency fridge-freezer, Full-HD LED monitor, low flow shower-head). One KWh costs me about 5 euro cents (some 1.5 off-peak), so electricity savings alone don't justify big investments in cutting-edge energy-efficient technology. The second-hand Radeon HD 4350 graphics was an acceptible investment from that point, but that's about it for now. My system uses just one HDD as (primarily temporary) storage - the "eternal" decade-old Maxtor Diamond Max 9 of 80 GB (still going strong after about 2200 days of continous use), and the bulk of the multimedia is stored on low-end and offline technology for the time being - namely optical. My next system (in approximately 3+ years as far as my plans go) will probably be something AMD APU-based.

washu
Posts: 571
Joined: Thu Nov 19, 2009 10:20 am
Location: Ottawa

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by washu » Tue Sep 23, 2014 7:01 am

@gamebox: Yes, XP 32 bit executes HLT automatically. Win2K and ME do as well. The behavior you see is because the KT133 chipset is buggy and doesn't allow HLT to work properly without a workaround, which VCool does. If you had the same CPUs on a better chipset you would not need VCool.

You don't need to go new to get something much more efficient. If you could get a Core 2 based system for cheap/free it would still be a massive improvement in efficiency over what you have now. Especially if you could get one with an 80+ PSU. It would also be much faster and more reliable. First gen i-series are even better and starting to get cheap on the used market. If you can find one with a built in GPU then you don't need a separate video card to do HD.

Athlon XPs and 64s are not moderate efficiency, they are BAD efficiency. They were great in their day because they were fast, but they were not efficient. Not like the P4 was any better, that's just the way it was. The P3 while slower was quite a bit more efficient than the A64/P4 and everything newer is better as well.

While most of your old parts may be called reliable, your PSU is most certainly not. A PSU from that era is likely a ticking time bomb of bad capacitors. You may be lucky, but even good brand PSUs from back then often had bad caps. When it goes it may just stop or it may take out other components with it. Your motherboard also has a fairly good chance of having bad caps, especially a low end Foxconn board like that.

I very much understand the desire to keep using old equipment and get the most of out of what you already have. However you simply cannot get an efficient computer with an Athlon 64 and an old PSU.

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Tue Sep 23, 2014 8:23 am

@washu: You might be right about KT133 being buggy. I tested the board trying to get it decode YT in realtime, to pass it to my parents as barely-usable "internet access terminal", put together at no cost whatsoever and with mainly worthless bits. However, the Athlon XP 2400, despite being the maximum possible upgrade in that board over the old Duron 1200, still couldn't do YouTube - the SDRAM, sadly at only 100MHz, is an unforgiving bottleneck as it always has been to me for 8 years I used that computer. It is all about browser plugin's code-efficiency, I'm sure, as the CPU can decode even 720p video in standalone players in realtime, so it ought to be able to do the ridiculous 240p or 360p over YT. But, as it is now, I will go for DDR1 mobo for that system keeping the CPU and the rest, also reusing my old, recently surplus, 2x512 MB DDR1 RAM.

In my view, all AMD processors spanning from about 1GHz to first CnQ enabled generations required massive amounts of electricity to run - 50 to 90 watts. The worst being certainly the Thoroughbreds (sadly, the very same XP2400 I have in that second setup) as well as my once dream-CPU, Barton. It's not a matter of bad design, but power consumption not being an issue at the time. A64 gives me approximately the best single-core performance I can get, with (at least) somewhat improved efficiency on idle run (I don't happen to use it at full throttle that often anyway, especially now with GPU HD video decoding). The upgrade from Duron in 2011 gave me about 3x more processing power for the same consumption - still a decent step forward - and lowered idle requirements. I want to remain single-core for the time being, out of personal preference, and, besides, oldest multi-core CPUs are still rated at rather high TDP (often over 100W and certainly over AMD single-core maximum of about 89W and my current TDP of 67W). The Sempron APU (Kabini/Kaveri?) at 25W max. is (at the moment) my next goal and the next generational step I'll take (probably in 3 years or so).

My PSU (350W) is 8 years old. It's, well, an Everpower masterpiece. :D Or Rexpower. Or KME. Depending on where you happen to read it's name - on the sticker, package or manufacturer's label itself. It is somewhat strained as is, but voltages are still acceptable (about 5-10 % deviation from spec) and the system is stable in all situations. Besides, the CnQ A64 with energy-sipping Radeon 4350 can't put that much more load onto it than old Duron 1200 and (overvoltaged) GeForce4 did. The trashy 300W PSU in second setup (came free with the cheapest ATX case), although running the system fine, IS a true time bomb - it makes high-frequency whine even with the computer on standby and even worse noise on load, but the wellbeing of those old components isn't important to me. I've opened that one to look for obviously suspicious capacitors, but found none.

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by Vicotnik » Sun Oct 05, 2014 1:47 pm

gamebox wrote:@Vicotnik: The mobo is low-end, Winfast (Foxconn) K8CK804A05-6LRS, one of the first generation mobos with fan regulation - the CPU fan has 3 wires and no built-in regulating electronics as far as I know - the board does it instead. The mobo has four options in BIOS for this - Start PWM value (0-127): I use 127 meaning the fan starts at lowest possible speed (1300RPM), Slope PWM value: 8 PWM/C (steps of speed increase with temperature), PWM full-on temp: 56 (fan goes max rev when CPU reaches this temperature (which pretty much never happens)), and PWM start temp: 40 (that's the threshold at which the stopped fan starts spinning).
The manual for the K8CK804A05-6LRS sadly doesn't explain those settings.

I found this thread in the Anandtech forums
http://forums.anandtech.com/showthread.php?t=152331
I am just not clear about the meaning of these settings. I experimented with them, and here is what I found: Start PWM Value seems to influence how fast the fan spins when it is cold. PWM Start Temp seems to control at what temperature it starts to speed up. Slope PWM Value seems to control the amount of speed-up. Delta Temp doesn't seem to do anything.

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Mon Oct 06, 2014 7:03 pm

Hm, Anandtech says my IP is banned?! :/ I don't have a clue what is going on there...

PWM start temp is the sort of a threshold where *something* happens. Either a fan gets PWM-chopped voltage there or starts getting the voltage at all, but that's exactly the point where it starts spinning. I presume it is not getting the voltage at all before the threshold is reached. It will start rotating whenever system is powered up, and even at decent rev at that (probably about 3000) only to stop couple of seconds later, as it seems it takes a bit of time for the system (BIOS?) to read CPU's temperature and start the fan voltage regulating circuitry. The fan starts spinning again whenever the system is restarted (also shortly) or when CPU accumulates some heat through it's workload (there it starts and remains on).

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by Vicotnik » Tue Oct 07, 2014 12:26 am

It's normal for the BIOS to give full voltage to fans for a short while at POST. I don't know if that is because it takes a while for the readings to come in, or for the fan control to kick in, or if it's intentional to dislodge dust or making sure the fan starts. It's normal anyway.
When the fan has stopped, you should be able to determine if it gets zero voltage or if it gets a little voltage but not enough to spin. Carefully nudge the fan with a finger. You should be able to get it spinning a little by doing that unless it's turned off completely. It should at least pull more in one direction then the other, if there's any voltage there at all.
It takes more voltage to start a fan than to spin a fan that is already spinning.

I think what happens is this; you start the computer and it gives full burst to the fan, then fan control kicks in and the voltage to the fan is lowered to slow it down. But the voltage is too low, causing the fan to stop. As the CPU heats up the voltage to the fan rises and at some point it gets enough to start. Temps then lowers a bit and voltage to the fan drops, but this time not so much that the fan stops.

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Tue Oct 07, 2014 5:22 am

Hm, it might be the case, Vicotnik, but another thing I noticed too - if I restart very soon (while the system is cold) the CPU fan stops again right before system starts to load. But if I restart a well warmed-up system, the fan will continue to run while loading system. My opinion is that mobo creators wanted to give you the ability to make a fully silent system, the one that will not start a fan if you manage to keep the CPU temperature under set threshold, but will react quickly to cool it if things get out of control. It seems they only made that "error" - the fan won't stop again if CPU returns to safe temperature levels.

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by Vicotnik » Tue Oct 07, 2014 5:56 am

It's possible, but I don't think so. No CPU intended for that motherboard is meant to be cooled without a fan, even at idle. Usually the problem is the other way around; the system fails to POST if the fan spins too slow etc.
I think it's normal vanilla fan control, just that the "cold mode" setting (Start PWM value?) is set to aggressively, casing the fan to get some voltage but not enough to make it spin.
You could test this like I wrote earlier. If the intention was to stop the fan it would stop with no voltage at all.

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Tue Oct 07, 2014 6:16 am

I tried starting the fan by hand while it was off, but it didn't catch on. It seemingly is left powerless, but I might be wrong though... "PWM start temp", as the option in question is called, seems to mean that the regulation (probably the voltage supply to the fan too) starts at certain temeperature level, and I've set this to about 40 degrees as I noticed my CPU goes that low after longer periods of inactivity. It is still cooled, all the time, by case fan which I didn't remove although I intended to, since the mobo molex-connector it is plugged into wasn't giving way under reasonable amounts of force.

I was tempted so I tried CPUidle on A64, and all it did was to give it 100% load while running! :D Funny enough, in KT133 setup with Athlon XP 2400, software CPU idling works like a charm! The idle CPU even gets one degree cooler than the system eventually, and the PSU blows almost completely cold air out - so it seems the CPU consumes (almost) no power at all! That's exactly what I miss here - my Athlon 64 never gets that cold despite the CnQ, so it seems HLT states don't exist on it or at least are not activated. It seems A64 consumes 29.7 Watts of electricity (and wastes as much heat) just the same when being 33% loaded and when doing completely nothing at all (though I might test with a fresh system to rule out background software's influence (which I tend to keep at minimum anyway)).

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by Vicotnik » Wed Oct 08, 2014 10:15 am

I've read a bit about CnQ, mainly here
http://en.wikipedia.org/wiki/Cool'n'Quiet

"In Windows XP and 2000: Operating Systems "Minimal Power Management" profile must be active in "Power Schemes""

Also there's third party utilities like RMClock. I'd forgotten about that. :)

You could also give another OS a try, boot into Linux Mint or something with an USB stick. Check if CnQ works better with a more capable OS. ;)

gamebox
Posts: 27
Joined: Mon Sep 22, 2014 9:21 am

Re: Can I put an idle CnQ AMD CPU into HLT state as older on

Post by gamebox » Wed Oct 08, 2014 10:54 am

Thx for that utility, seems worth trying - will do as soon as I have some time of it. :)

CnQ actually works for my CPU, at least does what I read about it. I can easily see it changing through all three available power levels by monitoring the voltages on a CPU, and system information also displays different frequences too depending on the active state when accessed. :) To be honest, A64 I have has 3 power states, I'm just hoping for the "fourth" - with nearly zero-consumption on (close to) zero load.

Post Reply