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View Full Version : really cool temps (literally)



artoodeeto
03-06-2012, 10:55 AM
So I just hooked up my new AMD FX-8120 on a gigabyte mainboard...and apparently it's quite good at not running much voltage when idling - I'm getting 8 deg. C idle temps on the CPU (core voltage at idle is only 0.94V). I'm watercooling it; by contrast the Phenom II quad-core I just replaced idled around 38C. I'm using CPUID to obtain the temps.

I'm not quite sure I believe it, but it seems to be working fine. And it means my video card is running a lot cooler too: 34C at idle instead of 50C. Guess I'll see what happens when I run games tonight :D

Fuganater
03-06-2012, 11:03 AM
That seems way too low...

AmEv
03-06-2012, 11:09 AM
Hey, I'm using the built-in Linux temp monitoring software.
Says I'm getting 32.
Fahrenheit.

xr4man
03-06-2012, 11:30 AM
that's impossible. using either air cooling or water cooling, you can never get below ambient temperatures. the only way to get below ambient is to use something to "super cool" the heat sink or radiator. such as putting ice on your rads or piping your air conditioner directly on your cpu heat sink. sort of like phase cooling.
i think your sensor is bad or the software is reading it wrong.

AmEv
03-06-2012, 11:58 AM
I think so, too.

TLHarrell
03-06-2012, 12:31 PM
Couple peltier coolers in the loop too?

xr4man
03-06-2012, 12:38 PM
Couple peltier coolers in the loop too?

i was wondering if peltiers can get below ambient, but wasn't sure so i didn't mention them.

AmEv
03-06-2012, 12:53 PM
And freon isn't effective enough to cool a procy, right?

TLHarrell
03-06-2012, 03:02 PM
Yes, peltiers can go below ambient temps. A peltier (for those not familiar) is a device that when power is applied, one side gets cold and the other gets hot. You vent off the hot side, and have the cold side in contact with your cooling fluid in some way. A small water block on the cold side and a CPU cooler and fan on the hot side would be a good setup. You would need to regulate it a bit so you don't go too far below ambient and start causing condensation in your system. I may actually look into doing something like this for my build as my system sits in my garage area, and during the summer the temps can get pretty nasty. It would be great to be able to actively cool the system temps in this way.

Freon, and other related coolants, would indeed have the capacity to cool a procy. Problem is engineering the system properly. What you're looking at there is basically an air conditioner. You have an external compressor with radiators and fans. The coolant is brought into the block over the CPU and allowed to expand, chilling the block, then is returned outside where it is compressed again. It would be costly, and the likelihood of having condensation in your system is extremely high. It would also be an extreme energy hog as the systems cannot be throttled. They're either on or off. Off, and your CPU goes poof.

Twigsoffury
03-06-2012, 07:28 PM
So I just hooked up my new AMD FX-8120 on a gigabyte mainboard...and apparently it's quite good at not running much voltage when idling - I'm getting 8 deg. C idle temps on the CPU (core voltage at idle is only 0.94V). I'm watercooling it; by contrast the Phenom II quad-core I just replaced idled around 38C. I'm using CPUID to obtain the temps.

I'm not quite sure I believe it, but it seems to be working fine. And it means my video card is running a lot cooler too: 34C at idle instead of 50C. Guess I'll see what happens when I run games tonight :D

Boy it must be pretty cold in your room.


I feel as if parkas interfere with gaming myself, but to each his own.

artoodeeto
03-06-2012, 09:43 PM
Nope, ambient temps in my computer room are around 70F/24C. I'm sure part of it is that my rad is a blackice stealth 360, but it's also likely that the software is reading the temps wrong. Still, the lowest it gets is 8C; when I start up a web browser (like right now) or other program it'll bounce between 8C and 26C. Haven't tried a game yet to see what that does; I would expect when more voltage is run thru the CPU the temps will jump.

TLHarrell
03-06-2012, 10:15 PM
Sounds like a bad sensor. Not a chance even the best air or water cooling setup will drop your temperature to below ambient room temperature. That would require you to break the laws of thermodynamics, and may void your warranty.

It may be a bad connection, somewhere more or less resistance than what it should have, or maybe it's getting current induction from a power cable? I'd check the entire sensor loop. I'd also swap some sensors around to verify if one's gone wonky.

AmEv
03-06-2012, 11:11 PM
That would require you to break the laws of thermodynamics, and may void your warranty.

Almost sig-worthy...

nevermind1534
03-07-2012, 02:49 PM
My atom CPUs on my server (I use them mostly for minecraft and similar things) idle at around 8° C, but they're in a 40°F room. The laptop hard drives run at around 26°C (10° below the average for that model).

SXRguyinMA
03-08-2012, 10:51 PM
my i7-960 OC'd to 4GHz runs at ~56ºC while under 100% load from folding and idles around ~30ºC. Ambient temp in the room is ~25ºC

artoodeeto
03-09-2012, 12:56 AM
I'm guessing my temp sensors for some reason are about 25C off. No idea why, but every temp monitoring program I've tried shows the same readings. Gonna check the bios in a sec...

*just checked it. It's showing CPU temp @ 30C. That sounds more like it...but why would temp monitor programs in Windows show erroneous readings if the BIOS has it right?

TLHarrell
03-09-2012, 02:34 AM
See if the temp monitor program has an offset that's been entered for the sensors? Either that, or the program is whacked and not parsing the data from the board right.

Outlaw
03-09-2012, 07:45 AM
I didn't see the program for monitoring posted. Is it possible they aren't made for the FX line yet?

I know some of them that I had used in the past would be OK on my dual core but not on a quad. Or for specific lines in the core2duo/quad series (at that time).

artoodeeto
03-09-2012, 10:30 AM
whoops, forgot to post which programs I'm using. I've installed CPUID and Coretemp, both of which show the exact same readings. Coretemp has adjustable offsets while CPUID doesn't. but, I don't want to add an offset when I don't know for sure what it is. I'd say it's entirely possible they haven't been updated for the FX's yet - I've downloaded the newest versions of each but the readings didn't change from the prior versions. Guess I'll have to wait...unless anyone knows of another program that does read the FX sensors right?

Outlaw
03-09-2012, 11:01 AM
When you say CPUID, is that CPUID's Hardware Monitor Pro v1.19? There notes state it is for AMD Opteron Interlagos and Valencia (Bulldozer). BUT depending on when you bought the processor, it may be a Zambezi (which is based off bulldozer but doesn't appear to be the same).

http://en.wikipedia.org/wiki/Bulldozer_%28microarchitecture%29

Not sure how legit this review is. lol as irony sets in.
http://www.legitreviews.com/article/1741/18/

They state they use Core Temp 1.0, BUT what didn't make sense to me was this.
"The ambient air temperature in the room was 70F or 21C. We used Core Temp to monitor the temperatures and as you can see from the image above the low was 6C and the high was 46C. AMD says the maximum safe temperature to run any FX-series processor at is 61C, so the standard air cooler that comes with the retail processors is more than enough to keep it nice and cool."

Question, if you are testing with the OEM cooler, how is the low they seen 6c when the room temp was 21c?

I think the monitors just need more time to catch up.

artoodeeto
03-10-2012, 12:49 PM
Yep, I'm using CPUID 1.19 (and it shows the same readings as the previous version I had installed). My FX-8120 is definitely a Zambezi chip. I'd agree with you that the monitoring software isn't reading the sensors right. Time to wait...

Oh ya, and it looks like on that legitreviews site...well, the review of their experience might be legit. But it appears they didn't stop to think about the fact that a 6C processor is near the freezing temp of water, and if were really that low they'd have all sorts of condensation issues. :facepalm: