After several years of running my MSI Speedster based MythTV box I decided it was time for an upgrade. Not because the machine failed to handle its duties but because I was simply in the mood of building something new. I have to be clear that from a performance perspective, the Core2Duo Merom chip in the old machine was still fast enough for running MythTV. With the addition of VDPAU video decoding on a dedicated Nvidia card processor usage stayed low even during HD playback.
What has changed in the meantime
Intel’s integrated graphics solution (in my case the HD4600) has greatly improved since the days of the i945 chipset present on the old board. The latter was basically unusable for anything but the most basic of tasks. No dual head, no HDMI sound, no video acceleration. All of the above have been addressed making a dedicated card unnecessary. Not only will this save power but also lower cooling requirements.
Thanks to VAAPI Intel chips can now also do video decoding of the most popular formats in hardware. Haswell can currently do the following:
- MPEG2 decode
- MPEG2 encode
- H.264/AVC decode
- VC-1 decode
- H.264/AVC encode
- JPEG/MJPEG
- Video Post Processing
Power usage is now down from 78 watts at idle to a mere 25 watts. This should save me about 60 bucks in power bills a year. Not exactly enough to justify the investment but a nice side effect.
Hardware Changes
Processor
From a sheer power perspective a cheapish i3 would certainly be sufficient. But I wanted to have extra horsepower for the future, possibly also running VMware ESXi and so I went with a Haswell 4770S. 4 Cores, Hyperthreading, a low TDP of 65W and a full feature set for virtualization to IGP. When idling the modern processors use no more power than their lower spec cousins.
Mainboard
C’t magazine published an article about a low power (10W) Haswell build. This was inspiration for me and so I also chose to use the Intel DG87RL board even though intel decided to move out of the mainboard business. Aside from using little power, the mainboard also offers all the features I was hoping for:
DVI, Displayport and HDMI outputs, USB3 and a mSata slot and no legacy interfaces.
RAM
I chose a single 8GB Kingston Value DDR3 stick.
SSD
Samsung EVO 840 mSATA SSD
Given the Mainboard already contains a mSATA slot I bought a Samsung EVO 840 120GB disk.
Power Supply
My current Corsair PSU still works but does not run with a Haswell build for it does not support the Haswell C7 sleep states. Corsair described the problem like this:
According to Intel’s presentation at IDF, the new Haswell processors enter a sleep state called C7 that can drop processor power usage as low as 0.05A. Even if the sleeping CPU is the only load on the +12V rail, most power supplies can handle a load this low. The potential problem comes up when there is still a substantial load on the power supply’s non-primary rails (the +3.3V and +5V). If the load on these non-primary rails are above a certain threshold (which varies by PSU), the +12V can go out of spec (voltages greater than +12.6V). If the +12V is out of spec when the motherboard comes out of the sleep state, the PSU’s protection may prevent the PSU from running and will cause the power supply to „latch off“. This will require the user to cycle the power on their power supply using the power switch on the back of the unit.
This forced me to also get a new PSU. Maybe a good idea as the Corsair now has quite a few hours on its clock. I opted for a Seasonic Platinum P460. The P400 would have been the better option but was out of stock. I comes with a fully modular cable harness. The only problem I have is a clearly audible hiss from the PSU. It is a fully passive unit relying on convection and airflow within the case to stay cool. Because my Antec P180 (or the newer P183 variant) use a separate chamber for disks and PSU that is set apart from the rest of the case I need to include a fan in this chamber. in the past the PSU fan of the Corsair PSU was responsible for the airflow across the disks and PSU. With the new passively cooled Seasonic P460 I have a need for a case fan in the bottom.
Case Fans
I chose the Noctua Nf-s12a Uln, a 120mm low noise fan that comes already equipped with anti vibration pads and runs between 600 ad 800 rpm.
