Friday, February 09, 2007

Motherboard Duct Experiment

Will a motherboard duct better direct the airflow inside a small form factor PC to cool it's components more efficiently and quietly? A quick experiment to answer this question.

Cut from two pieces of thin cardboard.

Roughly what the duct looks like.

The duct height runs just above the ram and is wedged between the CPU heatsink and it's 92mm fan. The duct extends from the rear of the case (where it is sealed just above the 120mm case fan) towards the front of the motherboard where it is left open.

Top view.

Here the case side panels are installed, the duct is taped to the panel to form a seal.

Airflow is blown down into the duct by the CPU fan as well as drawn in from the opening at the front of the motherboard (left side in the photo) and drawn out through the rear case fan. The case side panels also has intake vents that coincedentally fall inside the duct height and will provide additional fresh air intake.

The duct fits closely to the 120mm case fan, but hopefully should not be overly restrictive for airflow.

Results to follow...

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Wednesday, November 08, 2006

HP e-vectra : makeover

The e-Vectra refinished with a fresh coat of paint.

This 6 year old PC was certainly showing signs of wear, including some scratches, scruffs, sticker stains, and areas where the color was beginning to fade.

I decided to repaint it's exterior and selected two cans of model spray paint. I selected glossy paint as I wanted a high gloss finish. First step was taking apart all the panels and washing them in detergent, then using masking tape cut-to-shape to seal off any areas I didn't want painted over (like the HP logo).

I painted the original cream colored panels silver, and for the dark blue panels I selected a slightly brigher royal blue.

The final finish was not quite as glossy as I hoped for, despite layering on the paint and waiting to dry between layers. Probably the rough surface of the case didn't help. However the case now looks close to new and is still shiny under bright lights.

Here is the finished case.

And the "before" look.

These photos were taken more than a year ago, but I just haven't had the chance to post them (it's now May 2008). The machine has since been given to a friend who needed a computer and has served faithfully as a web/email machine.

Back to HP e-Vectra : a closer look

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Monday, August 21, 2006

Linux on the Wall

My experiences building a small, low cost, low power consumption, diskless, linux data collection terminal left me with many thoughts to try and build a small silent linux PC. Certainly there are plenty of mini-ITX systems out there, but most tend to be somewhat pricey compared to say a regular desktop system. With the PC Chips VIA C3 800 mhz budget board, being only 5cm wider than a mini-ITX board, let's see what can be done.

This time around I found a Matsonic version of the PC Chips board. Besides the different color scheme (I actually prefer this traditional green to the red of the PC Chips board), and the Matsonic branding, everything else on the board is identical to the PC Chips M789CG. Even the contents of the manual is the same.

The Matsonic model number is MSCLE266.

The first step is to remove the noisy 40cm CPU fan and see if we can find a sutiable fanless heatsink replacement. I was able to remove the stock CPU heatsink fan without too much trouble. Beside the two plastic push pins, the heatsink is stuck to the CPU by a piece of double-sided thermal adhesive tape; wiggling/twisting and pulling up with my fingers did the job. I suspect removing the heatsink before turning on the system helps (the heat probably makes the tape stick even more), however please remember to take care as the CPU/board can be damaged and you may void your warranty.

The heatsink mounting holes are placed 60mm diagonally across from each other similar to northbridge heatsinks. The row of capacitors just next to the CPU also must be taken into account. Searching what was available in the local stores, I came across this Zalman, fan shaped northrbidge cooler, let's see how well it works.

The Zalman has two adjustable flanges that jut out from opposite corners of the heatsink, and had no problems fitting the mounting holes. Also the despite the wide fan-type fins, it is actually quite narrow along the other axis so there was no problem with the caps.

The base of the Zalman however was not as large as the CPU die and did not cover it completely, but there should be sufficient contact for proper heat transfer. Arctic Silver was used for the thermal compound.

With the motherboard placed in the open on top of a desk, an ambient of 29C, the temperatures were as follows:

IDLE = 44C - 35C - 34C
PRIME95 = 73C - 37C - 36C

74C is a little bit on the hot side, however it should still be within the C3 CPU's operating range, and the system remained stable. However temperatures would get hotter enclosed in a small case, let's see if we can find a larger heatsink that will fit this board and provide better cooling.

I had an old Zalman fanless VGA heatsink with similar adjustable mounting flanges which also fit on the board. It has two large aluminum heatsinks that sandwich the VGA card and are connected by one heat pipe. The mounting block is shown on the CPU, the large heatsink plate then attaches to this with the heatpipe held in between.

Here is the heatsink plate, it has quite a large surface area and is more similar to the stock heatsink seen on fanless VIA mini-ITX boards. Unfortunately it extends over the RAM slots, and about 2 cm would need to be cut off the plate to make it fit. For testing though, I did manage to shift the plate a little to the left to clear the slots, using only one out of the two screws to affix the plate to the mounting block. The side view below probably is easier to understand. The proper mounting position for the plate would actually slide the plate left just covering both RAM slots. The way it is mounted here is not ideal as the contact surface between the mounting block and heatplate is reduced (due to the indentation for heatpipe and other ridges).

However when the CPU was running, the plate got hot enough to suggest there was sufficient area for heat transfer. Unfortunately the CPU temperatures were no better than the Zalman fan-type NB heatsink, and the motherboard temperature actually ran 1-2C hotter probably because the heatsink covered much of the board. Despite it's larger size this VGA heatsink did a worse job, maybe if the heatpipe was installed and the second plate also used it would run cooler. Also the heatpipe would allow the second plate to be connected to an alumnimum case for even better heat dissipation, but for now we'll go back to the fan-type NB heatsink.
Adding a system fan would probably be safer so I tried several different fans with the open board, all placed next to the CPU blowing horizontally across the board. The temperatures under Prime95 where all quite acceptable.

Papst 80mm @ 7v = 46C - 37C - 36C
AMD stock 70mm @ 5v = 45C - 35C - 35C
Noname 50mm @ 5v = 54C - 36C - 36C

I spent a few trips looking through the grocery store, stationery stores, as well as the local dime stores for containers of suitable size. I considered cookie tins, food gift boxes, tupperware type containers. Eventually I decided to try this plastic A4-sized paper tray first. It's a bit larger than the motherboard, and a little tall, but it's tranlucent blue material doesn't look too bad (plus matches the blue Zalman heatsink), it has built in vent holes, and the shape looked quite suitable to fit the system without much modification. If the system ran well, I could always try other smaller containers.
For mounting the motherboard, I cut a piece of black cardboard to the shape of the plastic tray. As the tray is both wider and deeper than the MB, I decided to push the MB all the way to the front so as much of the connectors/peripherals connected to the rear I/O port would remain within the case for a tidier look.
I used two nuts to space the motherboard up from the base board. An additional nut on the other side to secure the screw.

I just happened to have a stick of GEIL RAM with a blue heat sink, which nicely matches the Zalman. It even has a built in temperature gauge, now it might actually be useful with a transparent case.
I attached the 70mm stock AMD fan to the base board with double-sided tape.

Of course the Pico PSU is perfect for this system. It's a little out of focus, but it's the tiny yellow board in the lower left of the photo.

And the last component, a Toshiba 512MB flash drive for loading the OS and saving any files/settings.

The slightly lower front side of the plastic tray makes for a nice opening that allows access to the I/O panel and a path for the cables to exit. The tray is held onto the base board with twist ties at the four corners.

Here is the system with the cover on. I temporarily attached a hard drive so I could run Prime95 and monitor temps under Windows XP (unfortunately not yet familiar enough with Linux to setup a temperature monitoring utilitly like LM_Sensors). Under Prime95, the CPU temp was the same as without the cover, the motherboard temp was higher by 6C (41C). After being run for a while, the RAM, PicoPSU, NB heatsink all felt quite warm. Even the top of the case and bottom also felt warm. However once it was mounted on the wall, it seemed to run cooler. I was unable to measure the temperatures under Prime95 (as now running Puppy Linux), but no part of the case felt warm. With the vent holes now on top, this probably makes for much better airflow/heat exhaust compared with being placed flat (top totally enclosed).
Because of it's light weight, the system is easily mounted on the wall; I used two photo frame hooks.


Installing Puppy Linux onto the USB flash drive was quite simple (this was described in Small System for a Small Budget ). The bootup time from the flash drive took about 1 minute and 20 seconds from the time the power switch was pressed.

Here it is driving my Dell 24" at 1600x1200 on the left (the right screen is connected to my main rig). Despite it's tiny 60MB size,Puppy Linux is a surprisingly usable OS (with the basic functions of browsing, email, chat, word processing, etc. and Open Office, Skype, among other programs can be added). Although certainly not fast, the app loading, screen refreshing times are reasonable.

Power consumption running Puppy Linux, 17-39 VA total power measured from the AC outlet. Assuming the AC/DC is working at a PFC of around 1, that would mean 17-39Watts.

One problem though with Puppy Linux is that it has no option to suspend the system, meaning you will need to power off the system instead. Also after shutdown, it does not automatically power off the PC either, you have to manually push the power switch which is a minor hassle. I suspect there should be some utililities/tools in Linux that would remedy this. Leaving this PC on all the time is not too bad with only 17W consumption, but still being able to suspend and wake from keyboard would be better.

And how about noise. Well without any hard drives, the system is certainly very quiet. The stock AMD 70mm fan is the only source of noise, and although very quiet when run at 5v, a very fain hum is still audible in a very quiet environment. As the system runs relatively cool, finding a quieter fan should not be too difficult to make this system practically inaudible.


Total Cost:
MB+CPU = $55
512MB RAM = $50
PicoPSU + 60W AC/DC adaptor = $60
Toshiba 512MB USB Flash drive = $15 Zalman NB Heatsink = $10
Plastic Tray + Cardboard= $5
70mm fan = $5
Puppy Linux = $0
TOTAL $200

This makes a nice small and quiet budget system for running/learning linux and performing light computer work in near silence. Mounting it on the wall means no extra floor or desk space is needed, and depending on your tastes it can also make for a nice piece of techno-wall-art or simply an interesting conversation piece. In the current setup, the PicoPSU has an always on green LED, an additional red one when powered up, and the flash drive a blue LED when accessed; RAM with LEDs (like Ballistix Tracer) could also be added to show the true working of the PC, or otherwise cosmetic case lighting added if that's your fancy.

What's next, well actually the cables inside are still a little messy (the unused molex/floppy cables from the PicoPSU). Also there are quite a few cables running down from the system (VGA, lan, keyboard, mouse, power, sound, fan controller) and although it is hidden from view behind the LCD, it would be nice to have a cleaner look. Changing to USB wifi, wireless keyboard mouse (with small dongles), and connecting the fan directly to 5v will help. Possibly replacing the base board with a more permanent alumnimum base. I've never been much of a fan for LED lighting, but for this case I am somewhat tempted...

Also how about a linux box in a cookie tin, this one just fits the motherboard with a little room to spare...

Go to Small System for a Small Budget
Go to Tiny Motherboard with 5W Processor for $60

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Sunday, August 20, 2006

Small System for a Small Budget

A budget system for under $260, monitor and operating system included!

In attempt to put together a small low cost data collection terminal, this little $260 system was born. This system makes use of the PC Chips M789CG budget motherboard we looked at earlier, with an onboard VIA C3 800 mhz processor and also a 8.4" LCD monitor to keep cost down. Certainly the low processing power and small screen means it won't fit most user's needs, but besides being a data collection terminal, it could work well for light computer use (email, chat, skype, some browsing) as well as fit easily in tight spaces.

Installing it inside a cardboard box is actually not part of the cost saving solution (a proper PC case is included in the budget). It was meant to test if a small sized case would allow the system to run with sufficient cooling. Although it does make for an interesting case and even has a convenient carrying handle!

Here are the components setup inside the box. The motherboard is fixed to the box with twist ties, while the PSU and HDD are attached with screws.

The power supply is a generic mATX sized. It's one fan is the only exhaust vent in this cardboard box case.

A simply flap opening allows access to the motherboard I/O panel.

The screen is a tiny 8.4" LCD (the brandname is Super), the lowest cost display I could find with a native resolution of 800 x 600. Although not recommended for extensive use, for simple data entry or short periods of use it is acceptable. It also has a built in TV tuner as well as AV inputs, built in speaker, and remote control. The high gloss surface shows it is mainly for viewing video, but once it is turned on, it's not bad for PC use. The screen is bright and sharp at 800 x 600 (it supports higher resolutions by interpolation, but those resolutions are not very usable). Contrast is a little strong, but can be adjusted, and colors are decent. The screen is powered by a low wattage 12v AC/DC adaptor. Instead of using the adaptor, the LCD ran fine powered off the 12v from the PC mATX power supply by simply connecting the LCD power cable to a molex connector.

Windows XP Pro was only used for initial testing, certainly this OS alone would blow the budget. The system booted up rather quickly, despite it's low processor, memory, bus speeds. XP was only run briefly, but for simple file navigation and launching of monitoring utilities, there was no noticable difference compared with a modern day processor.

Here is a shot of the system running CPUZ and Speedfan.

Here is a shot of the BIOS hardware monitor screen. The CPU runs at 1.65v, unfortunately there are no undervolting options. The temperature and fan speed is also monitored, but again no PWM support to control the fans.

As for boot devices, the BIOS does allow for a plethora of options including USB removable media. Hmm... how about booting and running the OS off a USB flashdrive!? I searched the internet and came upon BartPE , which is a stripped down version of Windows XP that can be boot from a CD (and also USB flash drive) used mainly for system maintenance purposes. This is probably better explained in Wiki. I managed to get BartPE to boot off a USB flash drive on my Asus Pundit system, as the BIOS allows the USB drive to emulate a regular hard drive,

but on the Via system, my Toshiba USB flash drive was only recognized as a floppy which does not work with BartPE. So I had to abandon this option and search further for a USB flash drive bootable OS. Eventually I came across a string of linux distros including DSL (Damn Small Linux), Feather Linux, and Puppy Linux. Being unfamiliar with Linux, I have always been shy to try it. However I ended up deciding to try Puppy Linux as there were several reviews mentioning successful USB boots using the easy install wizard that came with the distro, perfect for someone unfamiliar with Linux. Also there seems to be quite an active Puppy community with a lively forum and continuing upgrades, much more so than the other small distros.

Additional benefits include that Puppy loads completely into RAM and runs off RAM without needing to read/write to the flash drive during the session; only upon exiting will Puppy save/write changes to the USB flash drive. This is advantageous as USB flash drives have limited write cycles - even though the number of cycles is quite large, constant writing will likely wear out the USB flash drive sooner. On the other hand this does mean if there is a sudden power cut, any work will be lost, but if the data is saved to a server then this is not an issue. In addition with the entire OS loaded into RAM, the system should run faster. Well some of you may think that means the system needs a lot of memory, but actually the entire OS is only 60MB and will run on a system with as little as 128MB RAM.

The installation steps are quite simple.
1) downloaded the .ISO file
2) burned it to a CD using Nero (other CD burner utitilities will also work)
3) booted the live-CD
4) followed the setup questions/prompts to get into the OS
5) ran the USB install wizard (USB flash drive was plugged in before bootup)
6) booted Puppy Linux from the USB flash drive!

I initially tried Chubby Puppy, which includes Open Office. This booted without problem from the CD, USB install script ran succesfully, but when booting from the USB flash drive, a list of errors appeared and Puppy did not start up. Instead I tried the official version 2.02 (without Open Office) and reran the newer Install wizard and this time everything worked fine. Booting from USB was really a piece-of-cake with this wizard, just simply answering a few questions and following a few prompts!!

The system ran fine and temperatures were acceptable under load in the smaller cardboard box test setup. I tried to find a similar sized metallic budget case, but I could only find a larger book-type PC case.

Even this case is too large and there is a lot of extra unused space. Basically the front half of the case (right side in the photo) could be cut off as the system has no optical drive, and the hard drive could be squeezed above the PCI slots, but we won't attempt that here.

The power supply is a custom size, slightly smaller but longer than the mATX power supply. In addition to the PSU fan, the case also has a small 60cm fan next to where the HDD is installed. Don't be misled by the tiny keyboard, it's actually only 9" (or 23 cm) wide, and of course that's only a 8.4" LCD (1/4 the surface size of a 17"). The tiny keyboard was just handy for the install, a barcode reader will actually be used for most of the data input.

Using Speedfan to read the temperatures from the motherboard sensors, and a clamp meter to measure the VA power draw at the AC outlet:
This is inside the steel book-type case running Windows XP. These readings were taken inside an air-conditioned office, so I am guessing the ambient was around 24-25C.

IDLE = 56VA - 38C - 30C - 26C
PRIME95 = 74VA - 57C - 35C - 27C

As the generic case power supply has no PFC the actual AC power consumption in watts should be significantly lower, maybe only 60% of the stated VA figures. In anycase the power consumption figures are very low, and remember this already INCLUDES the power consumed by the LCD as it is powered directly off the PC power supply. With the HDD directly next to the fan, it runs very cool.

$55 = PC Chips M789CG Motherboard with VIA C3 800mhz CPU
$25 = 256MB DDR400 RAM
$55 = 40GB 2.5" ATA Notebook HDD
$100 = 8.4" LCD Monitor (800x600 native)
$35 = Generic Book-type PC case with PSU
$0 = Puppy Linux OS
$270 TOTAL

Ok, the title does read under $260, well a notebook HDD can easily be replaced by a regular 3.5" 80GB HDD which only costs $45 resulting in a $10 savings.

Alternatively the HDD can be eliminated altogether and replaced with a USB Flashdrive. The one I used is a Toshiba 512MB which cost $15, giving a total system cost of only $230.

How about noise, well although it is not a loud system, with the generic PSU fan, tiny 60mm case fan, and tiny heatsink fan, certainly it does not qualify as a quiet system either. However there is a lot of silencing, potential, especially with such a low power consumption system and diskless OS!

Back to Tiny Motherboard with 5W Processor for $60

Goto Linux on the Wall

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