Look what's inside Linus Torvalds' latest Linux development PC

The Linux creator recently announced he'd upgraded his main PC to a speedy AMD Threadripper 3970x-based processor. But a computer is more than a CPU. In an exclusive conversation, Torvalds talked about what's what with his latest system.

Linus Torvalds has no problem with Microsoft

In a Linux Kernel Mailing List (LKML), Linus Torvalds, Linux's top developer, talked about the latest progress in the next version of Linux: Linux 5.7-rc7. Along the way, he mentioned, "for the first time in about 15 years, my desktop isn't Intel-based." In his newest development box, he's "rocking an AMD Threadripper 3970x." But a computer is more than just a processor no matter how speedy it is, so I talked with Torvalds to see exactly what's in his new box. 

First, he's already impressed by its performance: 

"My 'allmodconfig' test builds are now three times faster than they used to be, which doesn't matter so much right now during the calming down period, but I will most definitely notice the upgrade during the next merge window," said Torvalds.

The AMD Threadripper 3970x comes with 32 cores. It's built using AMD's 7-nanometer "Zen 2" core architecture, and it boasts 88 PCIe 4.0. AMD claims it's up to 90% faster than its competition. Phoronix's independent tests found the "Threadripper 3970X absolutely dominates in performance and "outpaces the Core i9 10980XE."

Torvalds is a build-your-own box type of guy.

"I typically build all my own machines. Usually they are frankenboxes -- I'll re-use the case or the SSD from the previous machine or something like that. This time it was an all-new build," he said.

Why do it yourself? 

"I don't like having others build my machine, partly because I have my own specs I care most about, but partly I get self-conscious about getting donations that I no longer really need," Torvalds said.

Before this latest build, his box was an i9-9900k. Normally, Torvalds would just pop into the local Fry's to pick up some of the more basic stuff directly, but with the virus, this time it was all from Amazon. The pieces came in over a few weeks (no more two-day shipping of computer parts these days); the last two pieces came last Friday.

So, here's Torvald's annotated hardware list: 

CPU

"Initially, my plan was actually to do an AM4 board and just a Ryzen 3950X, which is the more mainstream upgrade," Torvalds said, but the "Ryzen 3950X would have been an upgrade over the Intel i9-9900K, but it would only have been an incremental one." 

"Normally, I go for the regular consumer CPU's, since they tend to be the best bang for the buck, and in the case of Intel CPU's I actually like that they just have integrated graphics. I don't care about the GPU very much, so an integrated one is fine, and it avoids the worry about picking the right GPU and possible noise-levels from one with bad fans."

Torvalds went "back-and-forth about that for a while," because, as he said:

"The Threadripper power use made me worry about noise. But I decided to do a big upgrade because unlike the traditional Intel Xeon high-core-count platform, AMD's Threadripper series still falls in the 'good bang for the buck.' So I bit the bullet, and am so far quite pleased."

Motherboard

See it now: Gigabyte Aorus TRX40 Master

Here, Torvald's main concern was:

"A board that had what looked like good power delivery and fan control. In the builds I do, I really want the basics to be solid, and there's little more basic than power delivery. Long long ago I had a couple of systems that were unreliable due to power brown-out, and I've gotten religious about this now. So I look for something that is  good for overclocking, and then I do _not_ overclock things."

In short, he wants a PC that can handle a heavy load, but he's not going to push the machine to its limits. That said, Torvalds absolutely detests:

"The default fan settings of this motherboard (very whiny small high-RPM fan for VRM [Voltage Regulator Module] cooling), but you can tweak the BIOS settings to something much better. Also note to anybody else: This is an E-ATX board, so it can be inconvenient in the wrong case."

Fan

As you can tell, noise is a big issue for Torvalds. He cares deeply about it:

"So I want good fans and coolers, and I've had good experiences with Noctua before," Torvalds said. "The extra fan is because I like that push-pull setup, and with a big 140mm Noctua fan running at low speed, I'm not worried about noise levels. Even when it ramps up under load, I don't find the noise of those fans annoying. It's more of a soothing 'whoosh" white noise sound, none of the annoying whining or rattling that you get with bad fans."

CPU Cooler

Torvalds uses two CPU cooler fans. The NH-U14S is the main one, while the extra NF-A15 fan is for the push-pull configuration of that cooler.

With all his concern about noise, why not water-cooling, you ask? 

"I'm not a fan of water-cooling. Reliability worries me, and I'm not convinced the AIO systems are any better than a good air cooling system. And the custom ones are way too much effort, and I worry about the pump and gurgling noises," Torvalds said.

Case

For the case, it's once again all about noise reduction. 

"I like Noctua fans better than the Be Quiet ones for some reason. But Be Quiet would have been my second choice, and Noctua doesn't make cases," he said.

Extra fan

Why an extra fan? Torvalds explained:

"The extra fan (the case comes with two already) is because I initially ordered the case, and then when looking at it I decided that it looks like the front intake looks more restricted than the back output (because of the front panel), and since I was waiting for other parts to be delivered anyway, I decided that an extra intake fan would be better for airflow, and hopefully cause positive case pressure and less worry about dust."

In the end, all the effort to make a quiet powerful PC was worth it. 

"With the right fan control setup in the BIOS (and assuming you picked the right fan headers: The motherboard paper manual had horrible pictures and I got the CPU and system fan header the wrong way round for the first build), you have a machine that is basically silent when idling, and without any annoying whine (but not silent) under full load."

Power Supply Unit

The GX-850 wasn't Torvald's first choice, but availability during the time of the coronavirus made it what it is, but "it should be solid," Torvalds said. He cares deeply about power delivery basics:

"I basically go 'what's the top power use of the machine?,' and then pick a power supply with a rating 2x that, and then look for reviews and reputable brands."

Storage

When it comes to storage, Torvalds is solid-state drives (SSD) all the way:

"I've refused to touch spinning media for over a decade by now, and for the last several generations I've tried to avoid the hassle with cabling, etc., by just going with an m.2 form factor. I've had several of the Samsung SSD's, they've been fine. A few generations ago there were lots of bad SSD's, these days it's much less of an issue, but I've stuck with what works for me."

Memory

RAM proved to be a sore spot for Torvalds:

"This is actually the least favorite part of the build for me -- it's fine memory, but I really wanted ECC [Error-correcting code} memory. I had a hard time finding anything [priced sanely] on Amazon, so this I feel is a temporary 'good enough for now' thing that works fine in practice."

Besides, he continued:

"I don't actually even need 64GB of RAM, since the stuff I do doesn't tend to be all that memory-intensive, but I wanted to populate all four memory channels, and RAM is cheap."

While games and artificial intelligence and machine learning developers care deeply about graphics, video and image processing doesn't interest Torvalds much. He used:

"Some random Sapphire RX580 graphics card. It's overkill for what I do (desktop use, no games)."

Linux

That's it.  

"Slap it all together, make sure you get all the fan settings right, and (in my case) install Fedora 32 on it, and you've got a fairly pleasant workstation," Torvalds said.

While for his main workstation, Torvalds builds his own, he also has cutting edge OEM PCs for "access to new technology that I might not otherwise have bought myself."

For his laptop, he uses a Dell XPS 13

"Normally, Torvalds said, "I wouldn't name names, but I'm making an exception for the XPS 13 just because I liked it so much that I also ended up buying one for my daughter when she went off to college.

Torvalds concluded:

"If the above makes you go 'Linus has too much hardware,'  you'd be right. Usually I have one main box, and usually it's something I built myself."

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