The Thelio line is a major improvement for the System76 desktop product line. It’s been a large project for a lot of our teams from product engineering to production to marketing and the web development team as well. System76 Founder and CEO, Carl Richell sat down to discuss the engineering behind the changes and how important the right to repair was in the endeavor.

What influenced the changes to the Thelio desktop line?

I think it was three years ago, maybe four years ago, AMD came to us and they said, we have this 64 core processor with 128 threads, it's Threadripper, and it doesn't work in Windows. So we need someone to launch this with, because Windows isn't going to be able to get the full performance out of it.

Of course we were excited about that, and they sent us samples and we had about three weeks. So we got these samples and they were 280 watt processors, which means they generated enormous amounts of heat that the processors before them just didn't produce, so we needed to handle that in our thermal system.

So we put the CPUs in our Thelio system and got to work on it. It was a couple of weeks of really long nights. But, we developed a few innovations that didn't require the case getting any bigger , which meant the volume on the desk could stay the same, and we were able to fully cool that 280 watt processor without any throttling.

What are some of the thermal changes to the desktops?

Originally the design had cool air coming in from the bottom and the cool air was shared amongst the GPUs and CPUs. To improve upon that, we separated the CPU cooling and the GPU cooling. So there’d be a separate channel for CPU cooling with its own cool air intake, and the GPUs would have their own cool air intake.

The changes started a few years ago, first coming to Thelio Major, but then we wanted to push the envelope further with Thelio Mega. Sometimes when you design products, you want to build something just to see if you can do it and just see how much you can do. And that's what Thelio Mega is.

It's able to handle over 1300, 1400 watts of thermal energy, which is a lot for a desktop. But in doing that process and developing that product over 6 to 8 months, we learned a lot about cooling. So what this new Thelio product line does is it takes the innovation that we developed when AMD came to us for the 64 core Threadripper and the innovation we developed to support quad GPUs and Thelio Mega, and apply all the thermal engineering to the rest of the product line.

Now Thelio, Mira, and Major have separate channels and separate cooling for CPU and GPU, which ultimately resulted in things like the Thelio being able to support the fastest Ryzen 9 processors available. They used to support up to Ryzen 7, now it's up to Ryzen 9 in a really small form factor. So it's incredibly dense performance in a small package, thanks to lots of effort and time of designing really efficient thermal systems.

Also with the thermal cooling and thermal changes, there's now side vents, many more side vents on the side of the systems.

What other improvements were made to the desktop line?

Cooling improvements weren’t the only change for the Thelio line. A big one is top I/O ports. For years, our customers have asked for I/O ports. It's actually a little bit more challenging than it seems because the top of our case comes off entirely from the internal. And the reason we designed it that way is because we wanted to make it really easy to service Thelio

By the top case being one piece and sliding off, you have access to all sides of the desktop to service it. But in doing that, there's an attached touch panel where the I/O could stick through. What we did to this update is to design a mounting point on the internal for the top I/O, which includes USB-A, headphone in, mic out and a USB-C.

We've bought a lot of machinery for the factory and that machinery means we have much tighter tolerances. So now we're able to produce an internal and external that always marries really tightly. And so those ports that are on the internal when you slide the top on, marry nice and tightly and look really sharp on the top. 

How important was the right to repair in the engineering process?

The right to repair was a considerable part of the engineering efforts. When we think about right to repair, it's designed into every part of our Process. We think 10 ifixit ratings are like one of the coolest things to get. And so we think about what things we would need to do to get that kind of rating from ifixit.

We went even further with this design. The biggest change was more fan headers. There are fan headers throughout the system to make it really easy to service. But besides that, the system itself has built in characteristics, which makes it easy to add memory and add drives. The drive cage is easily accessible when you take the top off.

You just put screws in and the screws are included on the internal so there's no separate screw bag that you might hide away somewhere and forget where it's at. Everything's integrated into the chassis. If you want to add a two and a half inch drive, three years down the road, the screws are all there inside the chassis to do so.

Adding a GPU is as easy as removing four screws, plugging it in, and, and putting the side brace back on. 

The right to repair is always important to us. It's something that we think about as being inherent in our design philosophy and our company ethos.  System76 always supports companies and initiatives that are driving for legislation that requires the right to repair.

How much work goes into optimizing the airflow?

When we're working on Airflow, we theorize about what changes are going to improve the thermal characteristics of the system.Thermal and acoustics are always combined as well, because the more you spin a fan, the louder it is on your desk, and we want to keep that system quiet. So there's a balance between those two. 

We start with CFD, which is simulating the thermal energy created by the different components, as well as the amount of cool air, and it's the CFMs that are produced with a fan. With that simulation, we can knock off maybe 60 or 70 percent of the different types of cooling arrangements that we might design into a product. Then the next 20 to 30 percent is all minute details in testing in real time, or on a real product. So we'll take that, we'll develop, we'll cut the product, we'll paint it, design it, build it.

Then we start doing hands-on testing with that concept. That's where we find that last 20 to 30 percent, like where the fence should go. Sometimes millimeter differences within the chamber make a difference. Turbulence is a big deal inside of cases.Computer cases that have something like 15 fans in them creates turbulent air that cannot flow in and out efficiently, and so it just can't cool the system.

Fan placement and distance from each other and paths for cool air to move from one from the cool place through the hot place and out and exhaust out is exceptionally important.

If the airflow is so strong, the computers must be really loud, right?

If you have that system that has 15 fans in it, it's going to be really, really noisy. But there are lots of subtle things. One, that's balancing the right amount of fans as well as developing fan curves that are appropriate for the amount of energy being used. For example, if the CPU isn't being utilized heavily, but the GPU is, then let's spin the GPU fans. If it's the CPU that's being used, not the GPU, let's use the CPU fan so we can reduce the number of fans running at higher speeds. 

With the balance of the overall system having cool air come in from different places, but without conflicting with each other, those fans can move at lower RPMs to cool the system. So there's a fan on the bottom and there's a fan on the side, both bringing in separate cool air channels that help with that. The quality of the fans matter a lot. That has to do much more with the motors, somewhat with the blades as well, but a lot with the motors. And, how quiet the motor is when it's spinning up and down, and a balance with the fan curve.

What often doesn't sound good is wrapping up the fan really quickly and then cutting it down, quickly as well. That is a jarring sound. So, ramping  up smoothly and bringing the fan down smoothly provides a better acoustic experience for customers. Then you can really get into some crazy stuff like the shape of the vents. There might be some things that we can do to push the envelope further by looking at the vent design.

Can you tell us about Thelio Spark?

The Thelio line has always been a professional, high end desktop line. Thelio Spark doesn't really take the high end part away, but it introduces our products to a new, starter class of desktop. One of the things about the Thelio line before Spark was that all of the components were exceptionally high end.

If you didn't necessarily need an i7 or i9 processor, or Ryzen 7 or Ryzen 9, you'd be getting oversized cooling. It wasn't adding any value or performance by getting a more expensive power supply that didn't add value or performance for a starter desktop. And when you combine these different things, like a very high end, high quality case it has unnecessarily oversized components.

The cost was too high. It was in the professional class price, but that alienated customers that don't necessarily need that kind of performance. And that's where Spark comes in. Spark is our desktop that has the same high quality standards that we have across the rest of our product line, but supports up to i5 processors and 4060 graphics cards.

It's essentially like your 1080p gaming machine. It's great for computer labs, it's great for... Programming, scripting, things like that. It's great as a family desktop, great for a general purpose business desktop for productivity tasks.

It's a new market for us and a new product that is much better aligned price wise for the performance that a lot of customers need, that we haven't supplied product for before.

What challenges did you face during the redesign?

When we think about designing products, everything is just a bunch of different things that you're doing in order. I don't necessarily think product design is challenging. I think of it as a project that's large, and then you take each individual piece and you just try to make it smaller and divide it so it's more approachable.

We wanted to make manufacturing more efficient and that meant removing some things. There's a part to the external that's called an extrusion and the extrusion is what makes the curves around the edges of the Thelio.

What we wanted to do was remove those curves, both for aesthetics, because it created lines that went along the front of the system, but also because assembling the system with those extrusions took a long time for the assembly team. So, we redesigned the exterior to use the brake to create those big radiuses, and we bought dies that go into the brake.

A brake is basically a large machine that you slide a piece of metal into. The hammer comes down, pushes on the metal, and creates a shape in it. Now we're using a brake to create that shape rather than a separate part. The challenging part with that, is that the extrusions had guides that helped the top slide on, so we needed to reproduce that ability, without having those guides. Now it's one piece of metal that goes all the way around and is just formed.

So we did some things on the internal chassis, like we added a guide on both sides and we added small spacers on the front. So as the top is put on, it slides. It feels like it stops in the right place and slides down. That was one of the unique challenges. 

One of the constant issues with desktop design is PCI slots. PCI slots were designed 40 years ago now and GPUs are now enormous. They weigh seven pounds sometimes on their own with all the cooling on them. And they're three PCI slots tall. PCI slots just haven't evolved as the hardware has evolved, but we still need to support them and make it easy for our customers to add PCI devices or remove them.

With this change, we have new GPU bracing to help better secure graphics cards when they're shipping. We have new PCI slot covers so that it's easier to slide them in and they don't fall when shipping. There’s a lot of small little improvements like that. There are tiny little improvements in every area inside of Thelio.

What’s Next for the Thelio Line?

The next thing we're going to do is a lot of improvements like the top I/O, manufacturing improvements, PCI improvements, and different bracing that improves shipping for Thelio Mega.

Thelio Mega was the inspiration for a lot of the engineering changes that came down to the rest of the line, but now we're going to apply all the things that we did over the course of the last year in Thelio to Mega. That's our first step we are looking into.

We also plan on developing a Thelio Minor. That's been a long standing project we'd like to do. Essentially, that would be a Thelio design that replaces our meerkat. But we don't have quite a time frame on that yet. It's in the conceptual phases so far.

Explore the Thelio desktop line today! https://system76.com/desktops