Doom came to the CPU market last week as security researchers at Google Project Zero, Technical University of Graz, and Cerberus Security told the world of Spectre and Meltdown—apocalyptic sounding vulnerabilities in almost all the world’s processors.
The pair of exploits piggyback on the fundamental architecture of most modern CPUs. Most modern operating systems have a kernel that does the mediating between the operating system and the rest of the machine. The exploits take advantage of some clever engineering most chips use to speed up communication between the kernel and the OS. Readers can find a more in-depth description of the problem here.
Google Project Zero said it had no proof that anyone had ever used the exploits, but who could be sure? Panic reached fever pitch as Microsoft, Apple, and the Linux community pushed out patches to address the issue. But the cure to the disease came at a cost.
The patches reportedly slowed down the processors as much as 30 percent, according to The Register. The news panicked some PC gamers. How are they expected to deal with as much as a thirty percent slowdown of the CPU? That’s a nightmarish bottleneck when you’re trying to raid in Destiny 2.
Intel said in a press release that it, “continues to believe that the performance impact of these updates is highly workload-dependent and, for the average computer user, should not be significant and will be mitigated over time.” Problems related to the patch are more likely to affect enterprise solutions, such as cloud computing and other database applications.
Epic Games claimed the patch effected server stability for Fortnite. “The following chart shows the significant impact on CPU usage of one of our back-end services after a host was patched to address the Meltdown vulnerability,” it said in a blog post.
The patches might cause trouble in data centers, but it’s not impacting frame rates on individual machines. “Everyone needs to relax,” Paul Alcorn—a contributing editor at Tom’s Hardware, a website specializing in testing PC hardware performance—told me over the phone. “It’s not going to change your gaming experience.”
Alcorn told me that most users aren’t ever going to do the kinds of things with their computer that will make the CPU slowdown occur. “Any requests from the operating system that go outside of the user space and go into the kernel are going to take more time,” he explained. “That is going to incur latency penalties for certain classes of operations...normal amount of latency for that kind of operation is 150 nanoseconds. Now it’s going to go into the 400, 450 nanosecond range.”
For most end users, they’ll never notice a difference. “The client type desktop applications, gaming included, execute almost entirely inside of the user space,” Alcorn said. “So they’re not really doing a lot of calls to the kernel. They don’t issue a lot of system calls. The performance impact is negligible.”
Tom’s Hardware has been running tests on patched and pre-patched systems since it figured out what’s going on. It’s early days, but Alcorn said that the results between patch and pre-patched results have all been within the standard of deviation you’d see if you ran repeated benchmarks on a system. “There’s essentially no difference,” he said.
The one place gamers might notice a difference is in load times, especially on older hard disk drives that work with spinning platters. But if you’re loading off a hard disk drive as opposed to a solid state drive, your games were already loading slowly. On an SDD the games load so fast that most users may not notice much of a difference either way.
“Anytime that you’re accessing data on your storage device, we are seeing a little bit of an impact,” Alcorn explained. “With faster forms of storage...we’re seeing a little bit more of an impact....when you transition from one scene into another scene inside another game, the little hitch as the map loads, you may see a little bit more of an impact there, but that’s going to take some time to quantify.”
He said the Tom’s Hardware team has noticed a difference in load times and any other activity that involves reading a storage device. “In terms of gaming performance, that’s probably the only area that we’re seeing a material impact.”
These changes will hit enterprise applications such as SQL databases harder than simple desktop applications. Even then, Alcorn is confident the industry will resolve the issue without most users noticing a difference. “The patch that’s coming out right now is rudimentary, but it’ll get better,” he said.
I reached out to Intel for comment on this story and it referred me to a public statement it released on January 4. “Extensive testing has been conducted to assess any impact to system performance from the recently released security updates,” Intel said said. “Apple, Amazon, Google and Microsoft are among those reporting that they are seeing little to no performance impact.”