After reading SPCR for a while, I was finally convinced to boot the mini-tower Dell box off my desk and dive into mini-itx size computing. I purchased a used ISK300-150 case with a Foxconn D51S motherboard, 2x2GB ram, extra network card, Win XP Pro COA for real cheap [$65 off ebay]. Expecting really low energy consumption, I was amazed and disappointed to see 33-34W on my Kill-a-watt when fired up in BIOS. I added an 80GB HD and got all the drivers installed, system idling and it was still 33-34W. I cross checked a number of test sites and figured at the efficiency level of tested ISK300-150 PSUs - around 60% at 40W system load - that the system was using maybe 20-23W. Still not very impressive. I found an Antec MD-135 DC-DC power supply with harness and brick, the one used in the ISK300-65, and swapped out the 150W PSU. I got everything re-installed and amazingly, it was now showing just 20W, flashing 21W!
• Removing the second case fan I had installed dropped it to 19W flashing 20W
• Removing one of the 2GB sticks dropped another watt so it was 18W flashing 19W
• I noticed that PF was .53 and the ampere reading was .34A which seemed high to me. (The brick that came with the MD-135 is a Delta ADP-60HB AB, Level IV efficiency so 85% min.)
• I tried using an ISK110 brick [Delta ADP-90CD AB, Level V efficiency so 87% min.] with the MD-135 power supply and the Kill-a-Watt showed mostly 18W, PF was .92 and the ampere reading was down to .17A, more as you would expect.
• Putting the system [MB/memory, minus the slim-line CD/DVD] into an ISK110 resulted in the Kill-a-Watt showing 17W, flashing 18W occasionally.
So based on a total power supply efficiency of ~80%, and presuming that the Kill-a-Watt reading was ~17.5W [thus rounding up to 18W occasionally], working backwards, I guesstimated the system in the ISK110 was actually using around 14-14.5W (nearly 16.5W before removing the fan, 2GB ram and dropping the slim CD/DVD).
Doing the math back for the Antec 150W PSU, the efficiency at 11% load was only ~50%. Quite sad. It was obvious too by looking at the HD temp. The HD temp dropped by 6C/11F by removing the 16W space heater [PSU lost heat] underneath the HD and replacing it with the DC-DC 1-2W heater.
When I first got the used ISK300-150 system, it was really
noisy. I thought, "Mike C was right; that Antec 80mm fan sounds terrible." However, I discovered quickly it wasn't the Antec case fan. The previous owner had turned off PWM on the CPU fan and it was churning away at 5400rpm. Turning on PWM and setting the start speed at the lowest possible (1200rpm), some level of quiet came. I also discovered that the PSU fan was worse sonically than the case fan, and because of the inefficiency of the PSU, it was running all the time. I was not impressed with the CPU temps at idle; ~46C/114F with the case fan on low. Raising the CPU fan speed was marginally helpful, but it became audible by 1800rpm. I added another Antec case fan, but that only gained 2C and made the case fans noisier than the PSU fan. Checking out the stock heatsink, it seemed pretty small for needing to dissipate 13W. There wasn't much wiggle room for a larger heatsink other than something taller. I scored some ASUS North/Southbridge heatsinks off ebay for a couple bucks. The Southbridge would have been ideal for the NM10 chipset, but it appeared like the tiny heatsink was glued on in addition to pins, so I chickened out and left it. However, I replaced the dinky 42mm x 42mm x 13mm CPU heatsink and replaced it with the NorthBridge heatsink [46mm x 43mm x 33mm]. It was a pain bending the hold down clip, and I had to come up with a fan mounting scheme because the fins flexed. If you look closely you can see the small silicone tubing I pushed in between the fins to receive the fan screws. The heatsink replacement was very successful in that it lowered the CPU idle temp 7C/12F with the HSF at the same speed. I expect that using some heatsink grease was an improvement over the stick on pad too.
All in all, the install into the ISK110 wasn't too bad other than having to remove the front USB module to shoehorn in the MB. Fortunately, there was enough room to re-install all the screws for the module.
Moving to the ISK110 had the usual problem of keeping the HD cool(er). Long story short, I drilled out the ~2500 simulated holes on the HD side of the case, and picked up about 3C/5F improvement for the HD at ~21C/70F ambient. At that ambient, the temps were:
CPU -> ~39C/102F (CPU fan runs 1700-2100 to maintain this temp in the ISK110)
System -> ~33C/91F
HD -> ~36C/97F
In my dad's basement, they are about 1-2C cooler because it's about 19-20C at this time of year.
In retrospect, the first 600 holes took care of most of the problem. If I were to do it over, I would have only drilled out the those 600 holes that line up with the opening in the HD mount. Then pick up a 40mmx10mm fan, powered it with 5V and mounted it on the inside of the cover to move some air by the hard drive. I found some tiny screws that were long enough for the 10mm fan and were the right size to screw into two of the 5/64" holes in the cover and were flush with the outside surface. All I had on hand though was a 50mmx10mm fan that only fit up near the top of the case. It lowered the ‘system’ temperature dramatically [sensor must be on the underside of the MB or located on the top side near where I had the fan], but did nothing for the HD since the fan was above the HD. Live and learn.
I was quite content with this little box; it's pretty zippy compared to the 2.8GHz P4 it was going to replace. No gaming or movie watching going on here. It even did a respectable job capturing video during our campaign to get legacy video data off VHS tapes. I would like to have done more testing as far as energy efficiency and cooling and quiet, but it was re-purposed as a replacement for my dad's old Dell GX50 [1.4GHz PIII]. He was blown away by the size of the ISK110 and miniaturized components on the motherboard. It is definitely not silent, certainly quieter than the Dell and at a minimum, 200% more energy efficient. However for an 85 year old with pretty poor hearing, it will likely be silent for him! One of the best parts about this was that it was done on the cheap. Even adding in the external CD/DVD burner [the only new item of the system], the total came to ~$140. Now the time on the other hand... I think I had about 8+ hours in drilling and dressing holes in the case. But all those hours fiddling, tweaking, analyzing and engineering are a good part of the fun for me. Now if I could just learn to let it go at about the 90th percentile...
Looking through the gallery, this is pretty low tech and all old news for SPCR fans I suppose, but it's been a learning adventure here. I appreciate having a place to share about the project. I've collected enough parts to build another mini or two like this and a slightly larger file server based on an MI-008 case. But after having played around with the Antec ISK300, I've pondered using that for a file server too since I'm only using an SSD for the OS and 3 1TB 2.5" WDs for data. Time will tell, it always does.