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Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Sat Jan 05, 2013 2:46 am
by Gramkow
Came across this when I was browsing for a Mini-ITX board for the in-laws MCE, and it seemed too interesting to pass by - only one in stock :)

Information on this board seems pretty scarce, Asus's website doesn't even have a product page for the HDMI-equipped variant yet. Only difference seems to be the HDMI port though, so this link should provide some details: ... d/C8HM70I/

The essentials:
Intel HM70 chipset
Intel Celeron 847 ULV CPU, dual-core
Dual SODIMM slots, max 16GB RAM, DDR3-1066
PCI-e x16 slot
1 SATA 3Gb/s port, 1 SATA 6Gb/s port
2 x USB 3.0 ports on back panel

The board was not too expensive, paid around 80 euros for it. Currently I am just using it for testing / playing around, but it will probably end up on a family members desktop at some point. Test system currently consists of:

Asus C8HM70-I/HDMI motherboard
1 x 4GB Kingston SODIMM DDR3-1066 module
OCZ Vertex2 60GB SSD
bequiet PurePower L7 350W PSU

The CPU is cooled by a heatsink attached with pushpins, and a 40mm fan on top. The stock fan runs @ 4300rpm (apx) and sounds quite 'buzzy'. The motherboard has a 3-pin header for the CPU fan (monitoring only, no "smart" BIOS controls for fan voltage), and a 4-pin PWM header for a system or case fan - this does support Asus' 'Q-Fan' control system though.

With the stock fan, the CPU temperature reading just sitting in the BIOS is apx. 30C. This is on an open testbench (Lian Li T60), 22C ambient. I replaced the stock CPU fan with a Scythe Mini Kaze 40mm, 10mm height fan - at 12V this does apx. 3500rpm. This is a lot quieter, and does not exhibit the same buzz as the stock fan. I have since put a 9V resistor on the Scythe, which helps even more.

Will update this thread with some more details when I have time to test some more ... Am planning to test Netflix HD streaming in Windows 8, Blu-Ray playback with Arcsoft TMT5 and maybe a little stress testing of the CPU (Prime95 or similar). Will measure power draw as well.


Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Mon Jan 07, 2013 2:33 am
by Magsy
Very interested to know the power draw on this, please let us know when you have a chance :D

Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Mon Jan 07, 2013 2:50 am
by Gramkow
Tested it briefly over the weekend - the PSU I am using currently is only 80 Plus certified, so efficiency at really low loads isn't too good, so I won't go by those numbers.

I have an Akasa Crypto case with external 60W PSU arriving later this week - will test again when I get it fitted into that.

However, temperature measurements (using Asus' own Probe utility) look pretty decent. On the open testbench, running 100% CPU load with Prime95 (one thread for each CPU core) and running Blu-ray playback over the network at the same, CPU temp stabilized at 45C - up from 35-36C when idling on the Win8 desktop... Bodes well for decent operating temps when fitted into a case.

/ Gramkow

Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Mon Jan 07, 2013 4:03 am
by edh
I would definitely move to a passive CPU cooler on this and then have a zero moving part PC. Maybe there is no off the shelf passive cooler but with a little modification I'm sure many CPU coolers could be made to fit the bolt pattern for this motherboard.

Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Thu Jan 10, 2013 1:34 pm
by Gramkow

Got the motherboard and SSD fitted into the Akasa Crypto case today. Replaced the Akasa 50mm system fan with a Scythe Mini Kaze (SY501012M) and put a resistor cable on it - 9 or 7V, haven't measured. It is inaudible at that voltage but still moves a decent amount of air - certainly significantly more that the last Crypto build I did, where I used a 50mm NoiseBlocker fan.

So, power draw and temps. This is the 60W version of the Crypto, which has a smallish 60W power brick - it is quite a bit smaller than the 80W version they also sell.

All measurements taken using a pretty high-quality 'Made in Germany' power meter


Akasa Crypto Mini-ITX case with 60W external power brick
Asus C8HM70-I/HDMI motherboard
Kingston SODIMM 1 x 4GB, DDR3-1066
OCZ Vertex 2 60GB SSD

Idle Windows 8 desktop after disk activity settles down: 19-20 watts, CPU temp 39-40C
Prime95 with both cores loaded @100%, after 45 minutes: 30 watts, CPU temp 50C
Netflix HD playback using Win8 App, 21-22 watts, CPU temp 40-42C
TMT5 Blu-Ray playback, 25-26W, CPU temp 42C

All in all, really impressed with this cheap little build. I did try disconnecting the CPU fan and running Prime95 - temps rose quick to around 60C, and slowly from there up to 73C after apx. 10 minutes, when I stopped the test. So, fanless may not be the best option unless you replace the heatsink with something a bit beefier - or provide better airflow around the heatsink than what the Crypto offers.


Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Fri Jan 11, 2013 2:42 am
by Magsy
Thanks very much for coming back with those figures!

Personally a massive disappointment, double the wattage of the Intel NUC and right on a DQ77 board with an i3 etc (Huge price difference aside)

I was hoping these would be 10-15w, I've wasted a lot of money on fancy mobile itx boards and processors and unfortunately there seems to be a common theme, unless it is made by Intel efficiency sucks :(

Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Fri Jan 11, 2013 3:46 am
by Gramkow
Well, personally I am quite happy with the power draw figures, especially considering the cost of the system as it stands now:

Motherboard with CPU €80
SODIMM 4GB stick €20
60GB SSD €40 on sale :)
Akasa Crypto case 60W €80 including the Scythe 50mm fan

Total system cost was apx. €220 including shipping costs.

Efficiency would probably be a little better with a PicoPSU and class V brick, but I do not have any handy to test with, and it would be €80 spent on a possible 3-4W reduction in power draw.

The NUC itself costs around €300 in these parts, not including storage or memory - even going cheap on both, you're looking at a total cost of apx. €360

If we generalize a bit and say that a NUC would draw on average 10W less both for idle and load scenarios, then the extra power usage per year would look like this:
10W x 24 hours x 365 days / 1000 = 87,6 kilowatts per year
One kilowatt costs apx. €0,29 where I live, meaning the extra power draw would increase my energy bill by 87,6 * 0,29 = apx. €25 per year if the system is running 24/7.
Thus, the extra €140 for the NUC would take at least 5 years of continuous use to recoup on the power bill (all things being equal)...

I know that I am painting in broad strokes here, but the cost of the hardware needs to be factored in when discussing power efficiency and the total cost of ownership.


Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Fri Jan 11, 2013 5:21 am
by Vicotnik
Well, that's one way to see it. You could also say that by spending just a little bit more than that €220 you could have a beefier system (H61+G550 or something) and much the same power draw. ;)

Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Fri Jan 11, 2013 5:45 am
by Gramkow
It's a fair argument. However the current configuration suits the intended purpose just fine for now :-)

Mighty tempted to get a PicoPSU to test with though ... Vicotnik, you have a few of these and live in Scandinavia as well - where do you source yours (including power bricks) ?


Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Sun Jan 20, 2013 1:42 pm
by Gramkow
Got hold of a PicoPSU 90 and tried that with the C8HM70-I/HDMI board, to see if the Akasa DC-DC board was to blame for the poor efficiency.

It isn't.

Compared to the DC-DC board in the Akasa, the PicoPSU cut less than one watt off the idle power usage. Both tested with a class V AC adapter.


Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Sun Mar 03, 2013 9:55 pm
by mikecz
Is there any way to reduce the power consumption by changing settings in the bios while keeping the ability to playback hd content? (e.g. underclock)

Re: Asus C8HM70-I/HDMI motherboard (Celeron 847)

Posted: Wed Jun 05, 2013 2:05 pm
by David Harry
Hi Gramkow.

I was searching for some information on this board and came across your post. Thank you very much for your information, it was the main reason for me buying the board.

I know this reply is some time since you made your original post, but I had to reply to let you know what my experience is of the board.

My use for this board is for a data/video server, my iTunes library and a couple of applications as well as a home theater player.

First thing is the build. I was looking to build something as cheap as possible with a number of components that I had spare. I already had 4GB of memory, a 320GB drive and a Pioneer Blu-ray rom. I bought a CoolerMaster 120 case to put everything in to and also had a 90 Watt pico DC-DC supply spare.

Although I have a number of moving parts, the drive and rom, the noisiest thing is the cpu fan. As you have said it is quite buzzy, but by no means loud. The drive is only around 5000 rpm and barely audible and the rom only comes in to play when it is accessing media. I could always go SSD, but the drive is partitioned to give me a further 250gig storage partition aside from my external drives. I will look in to some kind of large passive heat sink at some point and see if it is good enough to be able to lose the fan. In any event, it is very quite as it is at the moment and as soon as I am playing anything, you don't hear the machine.

The big pull for me was a board with low power draw that had USB 3 and gigabit LAN, and the CPU is well enough for my use. I use Tversity to serve my videos. My library is quite large and consists of backups from my Blu-ray and HD-DVD library plus many backups of my old DVD library. Tversity shares my videos via DLNA to a few devices in my home, plus I also have it set up so that I can log in via the web. My BD and HD-DVD files are 1:1 backups, so have the same bitrate and file sizes of the original media. I also have compressed versions that are 720P with stereo audio, encoded by Handbrake using a h264/MP4 profile that matches my iPhone 5. These are for accessing remotely via the web, although at first glance the 720 versions look very close to the 1080 backups. My video media is stored externally on 4TB USB 3 drives. These drives are also used for local Windows file sharing on my network. I also use iTunes in shared mode for my IOS devises to pick up my music library. The music library is stored on the larger partition of the internal drive, this works well for now as an SSD would be over kill for my music and cost a lot more. I work in audio and film, and have the system also hosting my FTP for sharing media data with clients.

The system constantly runs Tversity, iTunes, Cute FTP server and windows LAN sharing. Between these main applications they are running in a combination of local access and web streaming/sharing. I am also running Windows 7 Pro 64 Bit on a very light install. The system is amazing. I have no problems at all serving all the data at the same time either locally or remotely. Although the CPU is not very powerful, it is easily up to the tasks that I need.

Oh, I also use the system connected to my home theater system. The computer is connected via the HDMI for both video and audio to my surround amplifier and my 50" plasma. I have not tested properly yet for the full HD versions of both Dolby and DTS, but the Intel GPU on the chipset is supposedly capable of this. The best media player I have found so far is the standard Windows 7 one, with the addition of the Shark007 codec pack. The whole thing is brilliant as a HTPC.

In any 24 hour period the system is probably in full use for about a third of this time. My power settings are set to shut down drives and video after a minute of none use, and some other tweaks for various MB components. I never let the CPU sleep, as this would stop my serving and wake on LAN is not an option, it just drops low when not in use. Between full use and low power state, the system goes between about 26 to 32 watts. The average power consumption is between 500 to 600 watts per 24 hours. This equates to less than 10 pence per day in electricity consumption. No matter how you look at this, it is very cheap. Yes, there are systems that will do less. But this system is running with drives and an an optical mechanism. The system that I used before this one used about four times the energy. This is a very low energy hit for something that is on all the time and just does its job of 24/7 data serving and streaming/playing.

This system is the most flexible and cost effective one that I have used to date, and no matter what you build around it, this MB and embedded CPU are fantastic value for money that is easily flexible enough to be used for serious data serving and as the heart of a HTPC. Transfer/backup speeds across my LAN between this server and the connected USB 3 drives and its gigabit interface, to my workstation. Are simply blazing fast, and basically use the full bandwidth of the LAN, averaging over 100MB a second.

Anyway. Gramkow, sorry if I have rambled on a bit. But thank you for your in depth information as it made my purchase of this board a simple one. And I hope my response is as useful to yourself. For anyone else viewing this thread, this MB is a serious piece of kit as long as you use for the right applications. There is nothing that can touch it as far as low power embedded CPU's are concerned, with USB 3 and gigabit LAN in the MINI ITX form factor. It would also work very well as a cheap small home PC, as it is brilliant for web use and runs OpenOffice very fast as well as a number of other apps that I have tried. It would not be very good for proper game playing, but anyone serious about games would be paying a lot more for something more suitable.