Budget folding rig

After running Foldingathome for a few weeks and watching my friends pull away and leave my machines in their dust, I decided to throw a little money at it and see if I could build a budget folding rig that wouldn’t embarrass me. While you can spend thousands of dollars on one, you don’t have to. Let’s see what we can do for a more modest amount. Like $200.

You can build a folding rig that can pull in 300,000-400,000 points per day for around $250. The trick is finding a decent minitower with a PCIe slot and a used graphics card.

The budget

budget folding rig
You can build a budget folding rig that provides high performance for around $250.

I chose $250 for this because it’s difficult, if not impossible, to reach that 400,000 points per day threshold for much less. It also represents something of a sweet spot. For half the price, you’re looking at setups that will pull more like 50,000 points per day. And to get much higher than 400,000 points per day, you’ll spend $200 on just the card alone.

If you want to do something fairly low effort for medical research and you’re fine with spending $250 plus another $16 or so per month on electricity to run it, this is something pretty attainable.

With some luck you may be able to come in as low as $200. Shop on Mondays to get the best prices. Here’s why.

The base PC for a folding rig

To start, you need a decent PC. Look for a minitower, ideally with something comparable to an Intel i3 or i5 in it. You should be able to score a retired office Dell Optiplex for $100 or less. Intel i5-4570-based PCs are coming off lease right now so those are pretty plentiful. And they’re pushing down the price of earlier i5s, like an i5-3470 or i5-2400. For folding, an i5 gives you some options an i3 doesn’t since it has more cores, but if an i3 is what you can find and afford, it will do fine. Don’t worry about getting the fastest CPU you can find, because the GPU will do the heavy lifting.

Just make sure you get a minitower. Many office PCs are low-profile models that won’t take a full-height graphics card. That limits you to low-profile cards that offer much less performance. For folding, you’re going to want a minitower.

If it has a Windows license that can be nice, but you can slap Linux on it if not. You can fold just fine on Linux. An SSD is nice if it has one (many office PCs started coming with 120 GB SSDs around 2014) but not necessary. Folding isn’t disk-intensive, but an SSD will lower power consumption a bit. If you’re paying $100, the system should have 8 GB of RAM too. You don’t need 16 GB to fold.

The power supply

The stock power supplies are fine for what they are, but they aren’t built for powering this class of GPU. Leave some money in your budget for a power supply with a 6-pin PCIe connector. I learned the hard way that the Thermaltake power supply I wanted to use is longer than the stock unit and wouldn’t fit my Dell’s case. Stick with a power supply that’s 140mm or 5.5 inches deep.

Surplus Dell 350W power supplies are a popular option. They fit, they cost $25, and look like original equipment.

Changing the power supply isn’t quite as easy as it looks. There are four screws in the back, but there’s a latch right in front of the power supply that holds it in place even with the screws out. Press down on that latch to free it.

The GPU for a $200 folding rig

The key to the $200 folding rig is the GPU. You want an Nvidia GTX 1060 or an AMD RX 580. These cards deliver similar performance and you can find used examples for $100-$120. The AMD card is a bit better performer, but at the cost of higher power consumption. The 1060 draws a bit less power, so it will give you more points per day per watt than the AMD.

If all you can get is a low-profile case, that limits you to a GT 1030, which doesn’t sell for much less than a 1060 even though the 1060 is 5-8 times more powerful for our purposes.

To make life easier on yourself, install the driver from the manufacturer, rather than the WHQL driver from Windows Update. Install the driver and reboot before you install the Foldingathome client. This increases the likelihood of everything just working right away.

Folding on the $200 rig

Once you procure the PC, GPU, and power adapter, it’s just a matter of installing the card, getting an OS on it, and loading the client. That varies depending on the OS you want to run; I’m going to assume you’ve done this before. Be sure to set up a passkey and use the passkey in the client so you’re eligible for bonus points. Otherwise you’ll never reach 300,000 points per day.

You can fold on your CPU as well. You’ll just lose one of your cores to the GPU slot. I can get 20,000-30,000 points per day with an i5-3470. The GPU’s doing the heavy lifting. Sometimes CPU work is easier to get, so it means your system isn’t sitting idle while it waits for a GPU job, but it’s up to you to decide whether to do just GPU folding or a combination of GPU+CPU.

It can take a week or so for a system to find its groove, so don’t worry too much about that. Once it does, you should be pulling in a couple million points a week. And that’s not bad at all for $200.

The $150 low-budget folding rig

If you can’t afford $150, you can build a folding rig for less. But for $100 less, you get about 1/4 the performance. It’s not efficient, but it’s a starting point, and if you’re careful, you can upgrade later.

For the GPU, get an AMD RX 460. You can get a used one for around $50. The good thing about these cards is they don’t need a supplemental PCIe connector.

Next, you need a system to put it in. Try to get an i5 if you can, because you’re going to need the CPU’s abilities. Also get a minitower so the card will fit. If you have to go a little higher than $100 to get an i5-4570 and can afford to, go ahead.

Between the CPU and GPU, you should be able to get just over 110,000 points per day. The $250 rig trounces it, but if you have $150 to spend, this lets you participate, and then you can upgrade to a better GPU. You’ll be able to sell the RX 460 for about what you paid, as it’s still a fairly capable card for gaming and doesn’t need a supplemental connector. That saves you from having to buy a power supply, at least until you upgrade, and makes the card easier to resell when you decide to do so.

Tricks for getting maximum performance on a budget folding rig

You don’t want to tweak the Foldingathome client too much. It’s definitely possible to tweak it to death and kill your performance. Once I get the GPU working, I make three changes.

The first, and biggest, isn’t really a change. Register for a passkey, then enter it in your client. The passkey serves as a unique identifier so Foldingathome can trust it’s actually you, and not someone trying to impersonate you to get points. This makes you eligible for bonus points. Bonus points are substantial. They vary from job to job but can be 5-10 times the base credit.

The second thing you want to do is open the FAHControl application, then click Configure, then open the Advanced tab. There’s a slider labeled Checkpointing Frequency. If your system doesn’t get interrupted a lot, slide that all the way to the right, to 30 minutes.  This lowers overhead and increases bonuses.

Last and least, if you have a fast computer or fast Internet connection or both, you might want to consider changing amount of time the system waits before the end of a job to start trying to grab a new job. By default, when the system is about 96-99% complete, it starts asking for a new job. This lets it get started on the new job right away after the old one finishes, but the bonus clock starts ticking as soon as the download finishes. By setting this lead time to zero, you delay starting the clock, at the risk of possibly having a little bit of idle time between jobs. On CPU jobs I recommend setting this to 100.

On GPU jobs, I say all or nothing. Set it to 100 to squeeze out a little more bonus, or set it to 90 to decrease idle time. There’s more demand for GPU work than CPU work, so if you start asking a few minutes earlier, you’re a bit more likely to pick up new work to start on right away.

To change this setting, open your CPU slot, scroll down to advanced options, then click Add. Enter the value next-unit-percentage and a setting of 100. Then do the same for your GPU slot, setting it to either 90 or 100.

One thought on “Budget folding rig

  • May 6, 2020 at 11:55 am
    Permalink

    Even if the off-lease computers originally had spinning hard drives, the refurbished ones usually have SSDs. Often that’s because they came from a company that required physical destruction of the original drives for security reasons, so the refurbishing company puts in a small SSD rather than a cheap HDD. A 120 GB SSD costs less than the cheapest hard drives that you can currently buy new.

    Reply

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