For the unaware, AMD recently launched a new line of APUs, codenamed "Trinity". I was curious about the idea of the APU when Llano (Trinity's predecessor) was released; I cannot help but think of the migration of discrete FPUs onto the CPU. However, I never tried Llano out for myself, so this time I decided to take a crack at it. Some folks have expressed an interest in the resulting build, so in the spirit of this article, I will attempt to detail it here.
First, I'd like to identify my goals for the reader. This was neither a budget-oriented project, nor pure performance. If the reader is interesting in overclocking or really stretching their dollar, I hope they can find useful information here, but this build was not targeted at them. To attempt a summary, I wanted to determine for myself the best APUs have to offer, in as small a package as reasonably possible. I will be using the computer for a mix of HTPC and gaming. My order of priorities goes something like this:
- Compactness
- Performance
- Price
This is not to say price is no object. Everything is weighted to my approximation of "within reason".
As this is a "compactness" build, let's start with the case. This decision was relatively straightforward, but definitely established a bounding box for other components. After some debate, I decided to go crazy. The Antec ISK-110 is what it'll be, folks:
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After some reading, I established a few notes:
- We are limited to about 90W, assuming the 92% efficiency claim can be trusted.
- CPU cooler height is limited. All I could determine online was the Scythe Kozuti (40mm tall) will fit. (I now estimate there's about 55mm of room)
- We will likely need a 4-pin ATX power extension cable- the ISK-110 comes with a very short one.
- This is, of course, an ITX only case.
This is really the heart of everything, and I expect if there is contention over the build, this is where it will be. I hope I may simply leave it at, in the ISK-110 case there is no room for discrete graphics, and AMD APUs have good graphics components.
It is already clear that we cannot pick just any APU, as we cannot power a 100W part. There are, thankfully, 65W parts. These are the fastest ones:
- A8-3800
- A8-3820
- A8-5500
- A10-5700
Personally, I recommend a Trinity part unless you are truly tight on budget. Tom's Hardware reports a 20-25% improvement in framerates over Llano, and this is supposed to be part gaming machine. I decided to go with the A10-5700. There were reports that even a 65W part might be tough to cool in the Antec case, but what the heck, we're being ambitious.
We're sticking a 65W part into a tiny case with zero case fans. It should already be clear, we need to carefully consider cooling. Initially, I decided the Scythe Kozuti was the way to go. Most importantly, I had reviews stating it fit in my dinky case, and second most importantly it performs well in tests. However, I eventually replaced it. While performance under medium load and idle was good, full load left the fan screaming and temperatures climbing beyond 60C. This may in part be the fault of my motherboard (more on that in a minute), so take my experience with a grain of salt.
Anyway, I replaced it with a Noctua NH-L9a. Pricey for a CPU cooler, but the ultra-low-profile CPU cooler selection is very limited, and I have found it performs admirably. Very quiet even at full speed, and cools the machine well. Another plus- it won't interfere with tall RAM, something the Kozuti cannot promise.
NOTE: Scythe suggests you leave the fan in the Kozuti pulling through the fins, down onto the board. This might make sense in most machines, but I found for whatever reason flipping the fan on the Kozuti improved cooling performance a few degrees.
This was one of the major pain points on this build. When I began, there was only one board- the ASRock FM2A75M-ITX. I found myself very disappointed with it.
- The board has components on the rear side in the backplate keepout, preventing the use of CPU coolers with a backplate (like the Noctua)
- The fan control seemed poor. You set a target temperature, and a target speed. The board runs at the target speed until the temperature is crossed, at which point the fan goes straight to 100%. Is this the normal way of doing fan control?
- For some unexplained reason, the CPU appears to be run full-bore during POST. My Kill-a-Watt reports 110W at the wall both during POST and idling in the BIOS.
- On that same note, the system draws 110W under load. What?
I was not particularly pleased, and several other users have reported issues with this board as well. The most common complaint is the VRMs run extremely hot and have no cooling. Thankfully, MSI just released their own FM2 ITX board. I switched, and I'm glad I did. I have had none of the stability problems or high power draw- indeed, the system now runs around 80W under load- and as a result cooling has improved as well. The MSI board is compatible with backplates for CPU coolers, and additionally has WiFi and Bluetooth built in, which are nice bonuses.
NOTE: The MSI board does not have VCore control. This is too bad, but acceptable. If you feel you need VCore control, I suggest waiting for Gigabyte's board, projected to be available in late December or January.
Unlike computers with discrete graphics, high speed RAM was important for Llano and it is important for Trinity.
Initially, I thought I'd be clever and overclock Samsung's 30nm "wonderram". If you haven't heard of it, they are 1600MHz ultra-low-profile (!!!) sticks that run at 1.35v (!!!) and can be overclocked with ease. To sweeten the deal even further, prices are very friendly at roughly $35 per 8GB. Really, they are the perfect sticks for this build.
Sadly, I had no end of trouble attempting to overclock the sticks. I later discovered that, apparently, users have had greater success overclocking them on Intel platforms. So, I moved on; there was a screamin' deal on 8GB of G.Skill 1866MHz Ripjaw sticks for $30 on Black Friday, and my "extra" Samsung sticks went into the desktop. The G.Skill sticks work just fine, though it should be noted that you do need to manually switch them to 1866MHz in the BIOS.
Prices on SSDs during Black Friday were great. I secured a Samsung 830 64GB for just under $65, and I am extremely pleased with its performance, particularly combined with UEFI boot mode. Throw in the lower power consumption and lower heat, and a SSD just makes sense for a tiny computer.
64GB is somewhat small, it is true. I decided this was OK, because it still provides enough space for 3 x 10GB games, and I am usually only working through one or two games. Additionally, I have some network storage.
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Antec ISK-110 : $75
-
ATX12V 4-Pin Extension : $2
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Noctua NH-L9A : $50
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G.Skill RAM : $30
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Samsung SSD : $65
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AMD A10-5700 : $125
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MSI FM2-A75IA-E53 : $90
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Xbox 360 Controller (wired) : $35
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Total : $472
I haven't truly put this thing through its paces yet, but the three games I have been playing (Mirror's Edge, Deus Ex: HR, F1 2012) are currently at high to max settings @ 1080p. I shoot for framerates around 30fps, which in Deus Ex (as an example) means everything maxed except for SSAO, Shadows, and texture filtering which are set to Normal/Normal/4x. That said, the settings do need to be scaled back a bit further to run in 3D mode.
NOTE: Allegedly, AMD GPUs perform better with MLAA, while NVidia GPUs perform better with FXAA. I have naturally chosen MLAA for Deus Ex.
I had a spare 120mm fan laying around, so "just in case" I attached it to the outside of the case. It turns out it was probably overkill, which is why I didn't include it in the total; even under full load, the computer is literally the quietest actively cooled device in the room, almost to the point of being completely silent.
As you can see, Noctua played it right up to the boundry but no further. If I had room in my case for a PCI-E card, it would fit fine.
Wiring obstructs airflow, and there are plenty of wires in this case. Arrange them carefully.
I took a few quick videos of gameplay, just to show it works smoothly. I flash through a bit of Steam's Big Picture mode as well.
Recording quality is not all that great, so I didn't try to prove settings or visual quality.
Big Picture, Mirror's Edge
http://www.youtube.com/watch?v=dBj45EtYQ6Y
Deus Ex: HR
I'm about to attempt this build with the same components but am worried that I'm cutting it really close on power consumption. Have you had any issues with stability or power draw on this system? How does it fare in synthetic benchmarks? I know the ISK 110's PSU can only provide 80w of power and I worry that's not enough to keep everything running at load.