The Test Setup
Before we continue, let me note the test setup:
- CPU: Retail boxed AMD Sempron 140 Sargas 2.7GHz, 1MB L2 cache, 45w TDP (socket AM3)
- Motherboard: MSI K9N6PGM2-V2 AM3/AM2+/AM2 NVIDIA GeForce 6150SE Micro ATX (mATX)
- RAM: Corsair XMS2 DDR2 4GB
- Hard Drives: Patriot PS-100 32GB / Seagate Momentus 7200.2 200GB
- Enclosure: Corsair Dominator GT BOX (yes you heard right, a box)
- PSU: PicoPSU 150XT with 150w power supply
Here is a picture of what is inside the box:
One can note from above that I only had one cheap DDR2 module, and the Seagate Momentus 7200.2 installed when I took that picture. To be quite honest, I was somewhat worried that it was going to go on fire so I decided to do the “burn-in” with a little less hardware before I became confident. Good news is that it survived 48 hours of x264 encoding with only getting a little bit warm. Also of note, the only fan in the entire system was the CPU fan. On low TDP “boxes” (sorry I had to use that term) I like using a maximum of one fan, either PSU or CPU heasink/ fan. The single fan setup works fine on my Intel Atom N330/ ION box, and both my Intel Core i3-530 and i5-650 rigs.
The AMD Sempron 140 is rated at 45w TDP and uses AMD Cool’n’Quiet to keep the idle power consumption low. How low? 31w (Kill-A-Watt watts) at idle in Windows 7 after everything has loaded:
At 31w, it compares favorably to the Intel Atom N330/ NVIDIA ION system that also showed 31w (on the same Kill-A-Watt). For this test I did remove the Seagate hard drive so only the Patriot PS-100 was installed. The power consumption is a bit higher than the Intel Core i5-650 though. Here’s a picture of that for easy reference:
Windows Home Servers spend a lot of time at idle, so this is an important figure. On the max power draw, I saw 67w. The i5-650 I managed to hit 78w, and the Atom N330/ NVIDIA ION I have seen only 42w from when loaded. Again, most users should focus on the idle power consumption for home servers since the CPU utilization tends to be very low on WHS machines.
For performance, I replicated my Windows 7 Windows Experience Index (WEI) tests, and saw something unexpected. Just as a note, I completely expected the CPU WEI score to be about 4.0. My hypothesis was off, by quite a bit:
That is pretty good. Just as a comparison the WEI CPU score of the N330 was 3.3 and the i5-650 was 5.9. At 4.6, the Sempron 140 running at 2.7ghz looks to be signficantly faster than the N330/ ION.
My next favorite test is x264 encoding. Full disclosure would dictate that CPU video encoding tends to do better with multiple cores, which would lead one to believe that the Sempron 140 is at a distinct disadvantage. On the other hand, x264 encoding using handbrake is probably the most CPU intensive task I use my main WHS for (I transcode 1080 camcorder witness prep recordings to lower-resolution files so people can watch themselves on iPod touches and iPhones), and since many people keep video files on their WHS, I like to post these numbers here’s a picture of the Sempron 140 encoding a DVD quality source file to x264 (via Handbrake v.0.9.4) for the iPhone:
By the end of the encode, the average fell to 28.71fps, but one can figure that the Sempron 140 does this type of encoding at just about real-time speed. To see how this CPU stack up here is the table from my i3-530 and i5-650 in the WHS review with the Sempron 140 added:
|x264 Handbrake Encode
In essence we have a big split between the WEI score, and the x264 encoding results. The x264 encoding results really favor the Core i3, i5, and i7 architectures and the multi-core + hyper threading nature of the newer Intel chips. The power consumption for the Core i3 and i5 chips ended up being slightly higher, but adding less than 30% additional power consumption when finishing an encoding task about three times as fast is a tradeoff anyone doing x264 encoding on their WHS should be willing to make, especially given the i3-530 and i5-650’s lower idle power consumption.
Some other important points on the Sempron 140. First, there is a possibility that one can unlock an additional core, effectively doubling theoretical performance. This comes with two caveats. First, one must have a motherboard capable of unlocking the additional core. These motherboards tend to cost an extra $20 or so, which is about the differential between the single core Sempron 140 and the dual core AMD Athlon II X2 240 Regor 2.8GHz 2 x 1MB L2. However, you get a slightly faster clockspeed, twice the L2 cache, and a guaranteed working second core with the Regor. The downside is that the Regor has a 65w TDP, and unlocking the second core on the Sempron 140 will add to the CPU’s power consumption.
The next note is that the motherboard I used, the MSI K9N6PGM2-V2 AM3/AM2+/AM2 NVIDIA GeForce 6150SE Micro ATX (mATX) motherboard is really not an ideal WHS board. It only has VGA output, and two SATA connectors (no eSATA). Another drawback is the NVIDIA NIC, which is one notch below the Realtek’s in performance. While expansion slots are available to add in a Supermicro HBA or a raid controller and Intel NICs, it really makes sense to get as much as you can integrated onboard. Why did I use this mainboard? It really comes down to the fact that I was at Fry’s and there was a $35 special for both the Sempron 140 and the MSI K9N6PGM2-V2. Essentially, Fry’s was giving the motherboard away as a loss-leader to get foot traffic in their stores. While the onboard nForce chipset may not be the fastest, nor have the lowest power consumption, the board is basically a bare minimum setup. It is still a mATX board, but it is not powering extra SATA ports and components, a second NIC, or even the circuitry to make a DVI or HDMI output work. Overall, I would say buy a more full featured AMD motherboard.
When using this setup with WHS (the board did work perfectly with my Adaptec 31605 so you can get a decent number of disks with it for a WHS), I did notice a troubling issue: DEMigrator.exe! When DEMigrator.exe was running, the Sempron 140 was pegged at 100% CPU utlization and things like remote desktop were running noticibly slower (not even smoothly). Being fair, DEMigrator.exe is known for eating CPU cycles, but it tends to load one core, on multi-core systems meaning that while disk transfers may be affected, the WHS system remains usable. DEMigrator.exe on the Sempron 140 really highlights the need for a second core in WHS, which explains why many of the pre-built Windows Home Server from HP, Acer, and etc. are shipping with multi-core chips.
The Sempron 140 does have hardware virtualization support which may be important. I tried running an OpenSolaris Virtual Machine in VirtualBox (running inside Windows Home Server). Let’s just say, the VM experience was not optimal. This is probably because I am accustomed to Core i7’s which are great for VM’s and the single core CPU was having trouble coping with the two OSes issuing commands.
Where the Sempron 140 really shines for a Windows Home Server build is value. The CPU is in the $35 or less range, and AMD motherboards are very inexpensive. $80 for a complete Sempron 140 system with a decent motherboard is not out of the question while an i3-530 + motherboard will likely cost twice that. The Sempron 140 sips power at idle and has a single core capable of running Windows Home Server. The 64-bit capabilities mean that, unlike some of the low-end Atom chips, the Sempron could run WHS V2/ Vail. Overall, the Sempron 140 provides a solid platform for Windows Home Servers.