HDDs may be a little box of aluminium, copper, and sometimes ceramics, but their most human trait is apparently that they slow down when you scream at them. One engineer discovered that 17 years ago, and I’m not too sure how.
Taking to X, Ben Dicken recently shared this discovery from Brendan Gregg, who is now presumably shouting at HDDs over at OpenAI, where he works. But before getting snapped up by Sam Altman, way back in December 2008 Bryan Cantrill uploaded a video to YouTube eloquently titled “Shouting in the Datacenter“.
Gregg showed that simply shouting loud enough could increase latency on a server rack, and he could even point out which area took the brunt of the shout, as their PC flags any disk that takes longer than normal to operate.
If you’re wondering why this is the case, shouting loud enough and close enough to the drive causes it to vibrate, and the drive vibrating can cause latency problems. You do need to be quite close to the drive for this to happen, though. Gregg, in the video, cups his hand around it and shouts right next to it. The video itself is in a data centre, and there’s a rather loud hum the entire time, which doesn’t appear to be causing any latency problems.
There are many physical components in hard drives which would explain why vibration can be such a menace. SSDs, on the other hand, don’t have the same weakness. They are not only faster, but also more sturdy as they rely on electrical currents rather than mechanical movements to read and write data.
Remember that time @brendangregg shouted at hard drives to make them slower?Someone please confirm nvme ssd is immune. pic.twitter.com/fbdKyEkMozJune 11, 2026
Hard drives are finicky things. So finicky, in fact, that Janet Jackson’s Rhythm Nation was once a form of a cyberattack, because the song contained the same natural resonant frequency of many 5400 rpm laptop hard drives. One could play the song from their machine and crash nearby laptops if they were fitted with the wrong drive. This was such a problem in fact that it plagued laptops between 2005 and 2009.
So don’t play Janet Jackson to your ’06 laptop and don’t scream at your hard drive. Luckily, I do neither of these, so I think I’m in the clear. Just imagine the destructive carnage you could cause on an ’08 data centre by screaming Janet Jackson.
Gregg says, “High latency caused by vibration is a real issue. You’ve seen it. It does exist”, to which Cantrill responds, “Just don’t let Brendan shout at your discs.”
Yeah, that’s probably good advice.