Category Archives: CPUs

Ultra-Low Power Consumption Computer Tested – 25 Watt AMD Athlon 5350 Quad-Core APU!

When it comes to the web server and file hosting world, where computers run 24/7, power consumption is often the leading concern when selecting hardware. The same is often true for low-load applications, such as HTPCs, where power and heat are at odds with a silent, inexpensive machine. For these machines, which might see an occasional spike in load but typically sit in a near-idle state, a low idle power consumption is key.

The place where lower power components are not as valuable is the high performance computing world. Here, the goal shouldn’t be isn’t the absolute lowest power consumed, but the lowest power required to do a unit of work.

Flipping this around, the goal is to maximize the amount of computational work done per unit of power. This is computational efficiency.

Computational Efficiency on Super Low-Power Computers

Most of the reviews on this blog have been on rather expensive, high-powered hardware. By this I mean big honking graphics cards running on 8-core machines with 16 GB of ram. I’ve even tested dual-CPU servers with 64 GB of ram, like the dual AMD Opteron workstation below:

Dual Opteron RIG

Dual Opteron 4184 12-Core Server – 64 GB Ram

In this article, I’m going in the other direction. I’ll be testing a little teeny-weenie computer, to see just how well an ultra-low power consumption computer does in terms of computational efficiency.

The Machine

Four years ago, AMD did something that some people thought was silly. They released a socketed version of one of their ultra low-power processors. This meant that instead of being constrained with a tiny integrated device like chromebook, people could actually build an upgradable desktop with a drop-in CPU. Well, APU, actually, since AMD included the graphics on the chip.

That processor was the Kabini architecture APU. Built on a 28 nm process, it went along with a new socket (AM1).  There is a really good overview of this here:

https://www.anandtech.com/show/7933/the-desktop-kabini-review-part-1-athlon-5350-am1

I won’t go into too much detail, other than to point out that the flagship chip, the Athlon 5370, was a quad-core, 2.2 Ghz APU with 128 Radeon graphics cores, and an amazing Thermal Design Power of just 25 watts! In a time when the most energy efficient dual and quad-core processors were hovering around 45-65 Watt TDP, this chip was surprising. And, it eliminated the need for a discrete graphics card. And all for $60 bucks!

So, I got my hands on one (not the 5370, but the slightly slower 2.05 Ghz 5350). The prices are a bit inflated now (some nutters want up to 300 dollars for these little guys on eBay, although if you are lucky you can get a deal). For example, this isn’t the one I bought, but it’s a pretty nice combo (board, ram, and CPU) for $72 dollars.

AM1 Build Deal

AMD 25 Watt Quad Core Deal!

Since the goal was to make a machine with the absolute lowest system power consumption, I got a Gigabyte GA-AM1M-S2H microATX board and two sticks of DDR3L (1.35 volt) energy efficient memory. The hard drive is an old, slow, single-platter (I think) Hitachi 80 GB unit, which seems to offer passable performance without the same power consumption as larger multi-platter drives. I used a Seasonic Focus 80+ Platinum 550 watt power supply, which is one of the most energy efficient PSUs available (I went with this vs. a Pico PSU because I wanted the ability to add a big graphics card later). I put 4 80mm case fans on a controller so I can take them right out of the equation.

Here’s pictures of the build. All the stickers make it faster…and external case fans are the bomb (put them on there for my kids to play with).

Defiant_Build

Low Power Consumption Build. Codename: Defiant

After a bit of fussing around, I was able to get the machine up and running with Linux Mint 19.1. Using my P3 Kill A Watt Meter, I measured a system idle power consumption of about 23 watts with the case fans off and 28 watts with the case fans on. That’s less than half of an incandescent light bulb!

Folding@Home Performance

I downloaded the latest V7 Folding@Home client for Linux and enabled 4-core CPU folding (I also set the computer up with a passkey to earn the quick return bonus points). I let it run for a month to make sure everything was stable. Here are the results from the latest week of CPU folding:

AMD APU PPD

AMD Athlon 5350 Folding@Home Production

As you can see, the machine is not fast enough to always return a work unit every day. However, using a 10-day average, the Points Per Day production is 1991.4 PPD. This is in the ballpark of what was reported by the client.

Power consumption when folding was 35 watts (30 with case fans off…with a system this small, the fan power consumption is a significant percentage). I thought it would have been a bit higher, but then again, power supplies are not very efficient at super low loads, and this machine’s mid 20-watt idle consumption is way, way less than what the Seasonic 550-watt PSU is designed for. As the power consumption comes up out of the ultra-low region, the PSU efficiency increases. So, throwing a full 25 Watt TDP of CPU folding at the equation resulted in only a net 10 watt increase in power consumption at the wall.

In short, running full-tilt, this little computer only uses 35 watts of power! That’s incredible! In terms of efficiency, the PPD/Watt is 1991.4/35 = 56.9

The following plots show how this stacks up to other hardware configurations. On the wattage plot, I noted which test machine was used.

 

AMD Athlon 5350 (25 Watt TDP Quad Core APU) Folding@Home Results

AMD Athlon 5350 PPD Comparison

The Athlon 5350 is not very fast…all the other processors do more science per day, and the graphics cards do a lot more!

AMD APU Efficiency Comparison

The Athlon 5350 is also not very efficient. Even though its power consumption is low, it does not produce much science for the power that it draws. It is, interestingly, more efficient than an old Intel Q6600 quad core.

AMD APU Watt Comparison

The Athlon 5350 is an extremely low-power CPU. The desktop build here draws less power than anything I’ve tested, including my laptop!

Conclusion

Super low-power consumption computers, such as one based on the 25-watt quad-core Athlon 5350, are good at (you guessed it) drawing almost no power from the wall. I was able to build a desktop machine that, when running full tilt, uses the same amount of power as three LED light bulbs (or half of one standard incandescent light bulb). It even uses less power than my laptop (and my laptop is tiny!). That’s pretty cool.

Sadly, that’s where the coolness end. If your goal is to do tons of computation, low-power PC parts won’t help (dur!). In the case of supporting disease research for Stanford University’s Folding@Home distributed computing project, the Athlon 5350 test system got spanked by everything else I’ve tested, including my 10-year-old Inspiron 1545 laptop. Worse, despite its ultra low power consumption, the sheer lack of performance kills the efficiency of this machine.

As a side note, I have been overwhelmingly pleased with the computer as a HTPC. It is quiet, uses almost no electricity, and is actually pretty quick at multi-tasking in Linux Mint’s desktop environment, thanks to the 4 CPU cores. This build also offers me the chance to test something else…namely pushing the efficiency of graphics card folding. By reducing the background system power consumption to an incredibly low level, the whole-system efficiency of a folding computer can be increased. All I have to do next is give this little computer some teeth…in the form of a big graphics card! So, it sounds like I’ll have to do another article….stay tuned!

Advertisements

Squeezing a few more PPD out of the FX-8320E

In the last post, the 8-core AMD FX-8320E was compared against the AMD Radeon 7970 in terms of both raw Folding@home computational performance and efficiency.  It lost, although it is the best processor I’ve tested so far.  It also turns out it is a very stable processor for overclocking.

Typical CPU overclocking focuses on raw performance only, and involves upping the clock frequency of the chip as well as the supplied voltage.  When tuning for efficiency, doing more work for the same (or less) power is what is desired.  In that frame of mind, I increased the clock rate of my FX-8320e without adjusting the voltage to try and find an improved efficiency point.

Overclocking Results

My FX-8320E proved to be very stable at stock voltage at frequencies up to 3.6 GHz.  By very stable, I mean running Folding@home at max load on all CPUs for over 24 hours with no crashes, while also using the computer for daily tasks.   This is a 400 MHz increase over the stock clock rate of 3.2 GHz.  As expected, F@H production went up a noticeable amount (over 3000 PPD).  Power consumption also increased slightly.  It turns out the efficiency was also slightly higher (190 PPD/watt vs. 185 PPD/watt).  So, overclocking was a success on all fronts.

FX 8320e overclock PPD

FX 8320e overclock efficiency

Folding Stats Table FX-8320e OC

Conclusion

As demonstrated with the AMD FX-8320e, mild overclocking can be a good way to earn more Points Per Day at a similar or greater efficiency than the stock clock rate.  Small tweaks like this to Folding@home systems, if applied everywhere, could result in more disease research being done more efficiently.

CPU Folding Revisited: AMD FX-8320E 8-Core CPU

In the last article, I made the statement that running Stanford’s Folding@home distributed computing project on CPUs is a planet-killing waste of electricity.  Well, perhaps I didn’t say it in such harsh terms, but that was basically the point.  Graphics cards, which are massively multi-threaded by design, offer much more computational power for molecular dynamics solutions than traditional desktop processors.  More importantly, they do more science per watt of electricity consumed.

If you’ve been following along, you’ve probably noticed that the processors I’ve been playing around with are relatively elderly (if you are still using a Core2 anything, you might consider upgrading).  In this article, I’m going to take a look at a much newer processor, AMD’s Vishera-based 8-core FX-8320e.  This processor, circa 2015, is the newest piece of hardware I currently have (although as promised in the previous article, I’ve got a brand new graphics card on the way).  The 8-core FX-8320e is a bit of a departure for AMD in terms of power consumption.  While many of their high end processors are creeping north of 125 watts in TDP, this model sips a relatively modest (for an 8-core) 95 watts of power.  As shown previously here, with more cores, F@H efficiency increases along with overall performance.  The 8320e chip should be no exception.

Processor Specs:

  • Designation: AMD FX-8320e
  • Architecture: Vishera
  • Socket: AM3+
  • Manufacturing Process: 32 nm
  • # Cores: 8
  • Clock Speed: 3.2 GHz (4.0 Turbo)
  • TDP: 95 Watts

Side Note: As many will undoubtedly mention, this processor isn’t really a true 8-core in the sense that each pair of cores shares one Floating Point Unit, whereas an ideal 8-core CPU would have 1 FPU per core.  So, it will be interesting to see how this processor does against a true 1 to 1 processor such as the 1100T (six FPUs, reviewed here).

All of my power readings are at the plug, so the host system plays a part in the overall efficiency numbers reported.  Here is the configuration of my current test computer, for reference:

Test Setup Specs:

  • CPU: AMD FX-8320e
  • Mainboard : Gigabyte GA-880GMA-USB3
  • GPU: Sapphire Radeon 7970 HD
  • Ram: 16 GB DDR3L (low voltage)
  • Power Supply: Seasonic X-650 80+ Gold
  • Drives: 1x SSD, 2 x 7200 RPM HDDs, Blu-Ray Burner
  • Fans: 1x CPU, 2 x 120 mm intake, 1 x 120 mm exhaust, 1 x 80 mm exhaust
  • OS: Win7 64 bit

Folding Results

Since I’ve been out of CPU folding for a while, I had to run through 10 CPU work units in order to be eligible to start getting Stanford’s quick return bonus (extra points received for doing very fast science).  You can see the three regions on the plot.  The first region is GPU-only folding on the 7970.  The second region is CPU-only folding on the FX-8320e prior to the bonus points being awarded.  The third region is CPU-only folding with QRB bonus points.  Credit for the graph goes to http://folding.extremeoverclocking.com/.

Radeon 7970 GPU vs AMD FX 8320e CPU Folding@home Performane

An 8-core processor is no match for a graphics card with 2048 Shaders!

The 8-core AMD chip averages about 20K PPD when doing science on the older A4 core. Stanford’s latest A7 core, which supports Advanced Vector Extensions, returns about 30K PPD on the processor.  In either case, this is well short of the 150K PPD on the graphics card, which is also about three years older than the CPU!  Clearly, if your goal is doing the most science, the high-end graphics card trumps the processor.  (Update note: Intel’s latest processors such as the 6900X have been shown to return in excess of 120K PPD on the A7 core.  This makes CPUs relevant again for folding, but not as relevant as modern high-end graphics cards, which can return up to a million PPD!  I’ll have more articles on these later, I think…)

Efficiency Numbers

I used both HFM.net and the local V7 client to obtain an estimated PPD for the A7 core work unit, which should represent about the highest PPD achievable on the FX-8320e in stock trim.

FX 8320e PPD Performance

According to the watt meter, my system is drawing about 160 watts from the wall.  So, 29534 PPD / 160 watts is 185 PPD/Watt.  Here’s how this stacks up with the hardware tested so far.

Folding@Home Performance Table with AMD 8320e

Conclusion

Even though the Radeon HD 7970 was released 3 years earlier than AMD’s flagship line of 8-core processors, it still trounces the CPU in terms of Folding@home performance. Efficiency plots show the same story.  If you are interested in turning electricity into disease research, you’d be better off using a high-end graphics card than a high-end processor.  I hope to be able to illustrate this with higher end, modern hardware in the future.

As a side note, the FX-8320e is the most efficient folder of the processors tested so far. Although not half as fast as the latest Intel offerings, it has performed well for me as a general multi-tasking processor.  Now, if only I could get my hands on a new CPU, such as a Kaby Lake or a Ryzen (any one want to donate one to the cause?)…