Via C7 - passive cooling feasible?

starbase218 · Post by **starbase218** » Thu Jul 15, 2010 12:21 pm

Hi,

I have a small NAS. It is based on a Via Epia-LN mainboard, 1GHz Via C7 cpu, 1GB Corsair RAM, a 1TB WD Green harddrive and a gigabit ethernet card. All this is stuffed into a Travla C158 case.

When assembling the system, I wanted it to be as silent as possible. So, I removed the case fan from. But, when I held my hand against the cpu heatsink, I noticed it got hot. So, I added a fan anyway. But now I figured I don't even know hot hot a C7 may become. In other words, it may feel hot to my hands, but is it really too hot for the CPU? Does anyone know how much heat a C7 can tolerate?

Now that it's summer, the harddisk has also warmed up, and I got the same question here. How much heat can a 3.5" hdd withstand, before I need to worry?

Thanks in advance.

Strid · Post by **Strid** » Thu Jul 15, 2010 12:34 pm

As long as it's below 40Â° C you're totally fine, but in reality anything below 45-50Â° C should suffice. (for the HDD)

As for the C7? I guess as hot as regular CPUs?

Do you have any temperature measurements? Also which OS are you running?

starbase218 · Post by **starbase218** » Thu Jul 15, 2010 12:39 pm

Strid wrote:As long as it's below 40Â° C you're totally fine, but in reality anything below 45-50Â° C should suffice. (for the HDD)

As for the C7? I guess as hot as regular CPUs?

Do you have any temperature measurements? Also which OS are you running?

I think the HDD is regularly at 50C. Without the fan, the cpu gets to at least 60C (very likely to become higher over time). I'm running Debian Linux, with several low power usage optimizations.

ilovejedd · Post by **ilovejedd** » Thu Jul 15, 2010 12:40 pm

Most electronics can withstand higher temps than we can. Most Via stuff tend to be targeted towards industrial applications so I would think that it should easily be able to handle fairly extreme temps (80C, at least).

themaster1 · Post by **themaster1** » Thu Jul 15, 2010 1:07 pm

50Â°C , i don't think so, well if you don't want your hdd to last it's ok i suppose otherwise it's more about 30Â°C.

To know the CPU tÂ° you have softwares for that: Everest and Cpuid HWMonitor pro

starbase218 · Post by **starbase218** » Thu Jul 15, 2010 1:15 pm

themaster1 wrote:50Â°C , i don't think so, well if you don't want your hdd to last it's ok i suppose otherwise it's more about 30Â°C.

To know the CPU tÂ° you have softwares for that: Everest and Cpuid HWMonitor pro

On Linux?

Anyway, I'll schedule a task that logs sensors and hddtemp output to a file. I should have the data tomorrow.

By the way, the fan is connected to a Zalman fan mate 2 at its lowest setting.

bonestonne · Post by **bonestonne** » Thu Jul 15, 2010 5:19 pm

I've got a VIA C7-D, and under passive use with the stock heatsink (something about twice the size of a basic northbridge cooler, as it covered the CPU and northbridge) it idled around ~43-46C when running passive. I fixed a 92mm fan on the CPU header (temp controlled) and it idled around 32C at low fan speed (~800-1000rpm).

A while back I tried getting a Thermalright HR-05 to fit on it, however I could never quite get the placement to work out, so it never fit evenly.

If i were to get a second HR-05, then I could try it out again, but right now I have no need to.

starbase218 · Post by **starbase218** » Fri Jul 16, 2010 1:36 am

Wow! That's a huge heatsink. It will never fit in my Travla enclosure though.

I actually ordered and received a Scythe Mini Maze Ultra to help cool down the HDD. But, I find it makes an unpleasent, kind of "in your face", noise. The reason for opening this topic is that I've actually read many people having a similar setup do not apply active cooling at all, and wonder if maybe I'm being over-cautious.

bonestonne · Post by **bonestonne** » Fri Jul 16, 2010 4:39 am

With little airflow, the C7 should be fine, but it's not something you'll want to watch a lot of movies on or do anything remotely intense on, because once it heats up, without active cooling, it's just not going to cool down a lot by itself.

it is very possible to run them fanless, you just need to have enough circulation to do it. It's hard to say whether or not a Travla enclosure has that just from the pictures though.

starbase218 · Post by **starbase218** » Fri Jul 16, 2010 9:44 am

I just looked at the BIOS and in the "CPU Feature" page it has options called "C7 TM1/TM2 Working Temp" and "C7 TM Overstress Temp". They are both at default (or should be, since I didn't change them). The first is set at 100C, and the second at 125C. If the CPU can handle 100C without any problems I might be over-cautious with regard to the CPU. LM-sensors indicates the "Int temp" to be around 70C. My best guess is that this is the CPU temperature.

starbase218 · Post by **starbase218** » Sat Jul 17, 2010 11:08 am

I was playing with the fans today and found that most of the noise generated by the Mini Kaze Ultra is actually caused by the fan vibrating. So I did a mod. I removed the existing fan and glued the Mini Kaze Ultra to a PCB connector, so that it sucks air in through ventilating holes and blows it out alongside the back of the hdd. I used the Fan Mate 2 to regulate the Mini Kaze Ultra, which I set somewhere in the middle. I think the system is a little quieter now. But more importantly, the hdd is cooler, stabilizing at 40C. I think this provides ample headroom for warmer days.

The now-passively cooled CPU is holding at 64C. So it's not cool, but it appears C7s are in fact designed to be quite heat-tolerant. So I think that's ok as well.

I don't watch movies on this system. It's mainly used as storage, providing 1 TB space for lossless music, photos, videos, etc. Music is played through a Logitech Squeezebox and photos/videos are played through an AC Ryan Playon HD mini. I also run SABnzbd+ on it for Usenet downloads. Perhaps a little overkill, but the NSLU2 I used before wasn't powerful enough to run Squeezebox Server smoothly.

I also managed to get Debian running even more efficiently, by enabling HPET. Apparently this helps to reduce CPU wake ups, allowing it to be idle more often and consume less power.

On a sidenote, I also replaced the PSU fan of my Antec NSK3480 by a Noctua. It's more quiet now. The most noisy device in that system is now the Seagate 7200.10 hard drive, which makes a whistling sound. Not sure what to do about that though... but that's a different topic.

starbase218 · Post by **starbase218** » Sat Jul 17, 2010 3:51 pm

Damn.. just when I thought I got it, the temperature does increase to about 70C at which point the server hangs. Guess active cpu cooling is necessary after all.

edit: seeing the "Int temp" is again at 70C, but the heatsink feeling a lot cooler due to active cooling, I had a feeling Int temp not being what it appears to be. Tried installing a different driver (c7temp) to monitor the temperatures, but that also reports 70C. But, the heatsink covers both the CPU and CN700 chip. So I guess it's probably the CN700 overheating.

starbase218 · Post by **starbase218** » Mon Jul 19, 2010 2:34 pm

Ok, just for the sake of experimenting, I removed the CPU fan again and left the system with just the HDD fan. It has been stable for over a day now. Guess the server hangs were not caused by overheating after all.