SPCR

First post! Good to be here. I've read reviews and forums on SPCR for years, but finally I have something to contribute.


I just finished building my zero-noise, fanless HTPC rig. Components:

i5-670
MSI H55M-ED55 motherboard
G.Skill Ripjaws F3-10666CL84GBRM 2x2GB DDR3 memory
Cooler Master Hyper Z600 heat sink (passive)
PicoPSU 150XT
Intel X25-M G2 80GB SSD
WD Green EARS 1.5TB HD
LG WH08LS20K BluRay burner
Mad Dog MD-16X3DVD9-8X DVD-burner (rebranded NEC ND-3500)
Rosewill R101-P-BK MicroATX Mid Tower

Everything was picked with low noise and power consumption in mind. Paying for an SSD was a painful experience, but in the end was well worth it... super low power consumption, and zero noise. WD Green is on stand-by most of the time (and is rubber suspended for good measure).

Regular PSUs made no sense to me; with my goal of 20W idle, PSU efficiency at very low power was essential. PicoPSU seemed like the only option.. maybe 150XT was a bit of an overkill, though.

I wanted to get the smallest case possible, but since I went with a MASSIVE passive heatsink (Z600), the case had to be wide enough to handle it (Z600 has to be horizontal for heat convection). Rosewill was one of the widest small cases I could find... The heat sink barely fits, but barely is good enough.


HOW WELL DOES IT WORK?

Performance-wise, this thing is a screamer! i5-670 is incredible, and coupled with an SSD, it's the fastest PC I've ever had. I don't need high performance, but I like snappy computers, and having LAME finish every MP3 track compression before EAC/MadDog is done extracting the next one is pretty neat. (And MadDog is pretty damn fast)

I also succeeded in my zero-noise goal. Unless I tap into my MP3 library on the WD1.5TB, the whole thing is dead silent... obviously. No fans, no noise. In fact, the noisiest component in my system is my LCD... an old Dell with constant 'whine'.

Running full blast, 4 threads of Prime95, the power consumption maxes out at 85W (off the wall, measured with a Kill-A-Watt). Doing the test right now; CPU temp is at +87C, which is pretty high, but Z600 is still doing a pretty good job, considering no fan on the heatsink OR the case (I left the PSU slot open for ventilation).


HOWEVER:

My treehugging goal of 20W idle didn't work out: the rig is idling at 22W. I was wondering if anyone had ideas on how to squeeze out the last two watts out of the system..?

In hindsight, I probably should've gone with Intel-branded stripped-naked H55 motherboard. Reviews seem to indicate it idles at even lower power than MSI...

I can't undervolt the CPU with the MSI board (!!). It probably doesn't matter, though; i5-670 powergates probably take care of most of the idle power (would help with load power, though).

I could undervolt some of the other components - mainly I was thinking DDR. Right now it's using the standard 1.5V. Tweaking the termination voltages might buy me some more as well... but haven't had time to do that... Also, I wasn't going to bother try if someone here has already done it, and noticed DDR3 undervolting doesn't help.

I could look at undervolting the H55 chipset itself, if you think it would work. I was going to shut down all the extra stuff I don't need (like PCIe links), but the bios doesn't let me, so no luck there.

I'm so close with this... two more watts! Any suggestions would be greatly appreciated!


Also, if you know of a good 1920x1200 LCD that has an HDMI/DisplayPort input and doesn't "whine", I'd be interested. 24-30inch should fit nicely. EnergyStar preferred...

Pics please

Third!

I`m quite surprised to hear that an modern MSI board doesn`t allow undervolting/turning off components. Have you looked at bios updates? It`s also possible that such options are hidden, for example many Gigabyte boards require you to press ctrl+F1 to access some more advanced options.

There is not much left to do other than that, except perhaps removing the dvd burner (though seeing that you rip cds often that might put unessesary stress on the BR drive). You could also remove one of the memory simms which most likely will let you reach your goal, not sure if its worth doing though. Maybe it`s worth doing it once just for kicks

If you can't under volt, then under clock (if you can). They both effect power consumption. The advantage to under clocking is no negative impact to stability.

It's possible to run an i5 passively? I'd never imagine... Isn't 87C too hot?

You're going to have to explain this one to me...

http://processorfinder.intel.com/detail ... Spec=SLBLT#

i5 670 TDP is 73W, and TJ max (maximum junction temp at the CPU) is 72.6C.

So either you're not getting an accurate measurement of your CPU temp or ... you're not reading the temperature correctly. If you were over TJmax your PC would shut down, and if it didn't shut down, your CPU would burn up.

I'm curious about your idle power as well - in a system I designed with a single SSD, no disk drive, and an e4500 (65W TDP), single notebook optical drive, and mini-itx board, I was only able to obtain 28W idle. How did you get less than that with more components and a higher power CPU?

mark314 wrote:You're going to have to explain this one to me...

http://processorfinder.intel.com/detail ... Spec=SLBLT#

i5 670 TDP is 73W, and TJ max (maximum junction temp at the CPU) is 72.6C.

So either you're not getting an accurate measurement of your CPU temp or ... you're not reading the temperature correctly. If you were over TJmax your PC would shut down, and if it didn't shut down, your CPU would burn up.

I'm curious about your idle power as well - in a system I designed with a single SSD, no disk drive, and an e4500 (65W TDP), single notebook optical drive, and mini-itx board, I was only able to obtain 28W idle. How did you get less than that with more components and a higher power CPU?

The Thermal Specification uses TCase (temp on the center top side of the heatspreader) so expect core temps to be higher. I seem to recall reading somewhere that TJmax for the core is 100C with throttling occuring at ~95C.

Clarkdales are very power efficient and they don't really use 73W during normal operation. Also note that the 73W TDP covers both CPU and IGP, whereas you still need to add the power consumption of the IGP on LGA-775.

b_rubenstein wrote:If you can't under volt, then under clock (if you can). They both effect power consumption. The advantage to under clocking is no negative impact to stability.

I might; to reduce the max temp a bit, but I don't necessarily want to lose the performance... I would much rather underclock.

Maybe there will be a nice bios update sometime in the future... <fingers crossed>

zodaex wrote:It's possible to run an i5 passively? I'd never imagine... Isn't 87C too hot?

87C isn't really too hot; these things are designed to work at those temps for some 5 years or so. I'm not running Prime for 5 years in a row...

When idling, the temp is pretty close to room temperature.

Clarkdales are pretty low power; passive cooling is possible, as long as the heatsink is good enough. Hyper Z600 is a huge heatsink, but the blades are spaced apart so convection can work its magic.

I'm not sure if it's being sold anymore... I got a refurbished one from Cooler Master website.

mark314 wrote: I'm curious about your idle power as well - in a system I designed with a single SSD, no disk drive, and an e4500 (65W TDP), single notebook optical drive, and mini-itx board, I was only able to obtain 28W idle. How did you get less than that with more components and a higher power CPU?

The TDP values relate only to the maximum power consumption the part can have. Clarkdales have much lower idle power consumption than Conroes because of extensive use of power gates. Also, E4500 is a 65nm part; Intel moved to high-K metal-gate transistor structure at 45nm, which reduced power consumption and leakage.

alleycat wrote:Pics please

I took a lot of pics while building the rig, but haven't had time to upload them... will see if I have time this weekend (probably not )

Why u didn't go for an Antec Three Hundred case with Scythe Orochi Heatsink? That was a much better combination! Temps were probably much lower then.

It's always the best to get the largest cpu-heasink you can get and a big tower case with much air holes at the top if you want to cool things passive.

That probably would've worked. I didn't know about Orochi - I guess I didn't do my research.

I wanted to make the system small; initially I was thinking of a small-box with a mini-ITX board and a low-profile active cooler. I ditched the idea because of noise, but still wanted to make the system somewhat small.

To be honest, I'm not too concerned about the temps... I believe these CPUs are designed to handle high temps pretty well - they have thermal diodes to trigger throttling if the temp gets too high.

But your suggestion is interesting; maybe I'll try to make a Gulftown-based passive-cooled system using Orochi and that Antec case.

please post pics.... pretty please!

That heatsink is bigger than the MSI mobo.


Side shot. looks like it'll work pretty well...


PicoPSU plugged in.


Initial boot successful!



All plugged in; heat sink barely fits.


Everything fits... barely.



A well-deserved break......

Add some ventilation, it might reduce power consumption by allowing the MOSFETs to operate in a lower ambient temperature, thus more efficiently.

Ehanks for the suggestion. That might help with load power consumption, but at idle the temps are so low that the temperature probably doesn't affect the results much..

That cooler is MASSIVE!!!

It's pretty large, but does the job nicely.

.

Nice, I like your style!

Nice Maß! Awesome rig, too.

I'm also using a similar processor, the i5 680, and my passive system is idling around 20c as well, so perhaps our thermal monitoring reports are correct after all. Besides, since we aren't using the IGP, our CPU is never pulling the full 73w TDP, probably maxing somewhere in the 60w TDP range.

I'm using the IGP... I think it's the most power-efficient way to get the 2D graphics done while keeping idle power low.

NeoGeo wrote:I'm also using a similar processor, the i5 680, and my passive system is idling around 20c as well, so perhaps our thermal monitoring reports are correct after all.

I doubt that. No thermal monitoring is correct ever. What's your ambient temperature?