Computers have gotten faster when it comes to computations—CPUs are astronomically more powerful today than they were in the early days of personal computing. Thanks to some painstaking tests by engineer and super nerd* Dan Luu, we now know of one area where computers have gotten slower: “the latency between a keypress and the display of a character in a terminal.”
Which is interesting.
In a blog post (via Gizmodo), Mr. Luu detailed his findings after months of testing every device he could get his hands on. Using two high-speed cameras, Mr. Luu tested how long it took for a character to appear on the display after after he pressed the key on the keyboard (virtual or real).
In the table below, you’ll see Apple’s venerable Apple //e—a device that was released in 1983—is the fastest of the 22 computers he tested. It took 30 milliseconds on the //e. Compare that to the 200 milliseconds it took on the PowerSpec G405 running Windows 10—a device released in 2017.
Dan Luu’s Latency Test Results
|apple 2e||30||1983||1 MHz||3.5k|
|ti 99/4a||40||1981||3 MHz||8k|
|custom haswell-e 165Hz||50||2014||3.5 GHz||2G|
|commodore pet 4016||60||1977||1 MHz||3.5k|
|sgi indy||60||1993||.1 GHz||1.2M|
|custom haswell-e 120Hz||60||2014||3.5 GHz||2G|
|thinkpad 13 chromeos||70||2017||2.3 GHz||1G|
|imac g4 os 9||70||2002||.8 GHz||11M|
|custom haswell-e 60Hz||80||2014||3.5 GHz||2G|
|mac color classic||90||1993||16 MHz||273k|
|powerspec g405 linux 60Hz||90||2017||4.2 GHz||2G|
|macbook pro 2014||100||2014||2.6 GHz||700M|
|thinkpad 13 linux chroot||100||2017||2.3 GHz||1G|
|lenovo x1 carbon 4g linux||110||2016||2.6 GHz||1G|
|imac g4 os x||120||2002||.8 GHz||11M|
|custom haswell-e 24Hz||140||2014||3.5 GHz||2G|
|lenovo x1 carbon 4g win||150||2016||2.6 GHz||1G|
|next cube||150||1988||25 MHz||1.2M|
|powerspec g405 linux||170||2017||4.2 GHz||2G|
|packet around the world||190|
|powerspec g405 win||200||2017||4.2 GHz||2G|
|symbolics 3620||300||1986||5 MHz||390k|
There’s a reason for this, as Mr. Luu details on his wonderful blog: it takes more steps to get the character from keypress to screen now than it used to take. This especially true for operating systems designed to run on wide arrays of hardware.
Those extra steps are part and parcel of the many more things modern devices can do, however, and the reality is that few of us notice this lag.
Scroll Latency on Mobile Devices
Dan Luu also put together a table of scroll latency on just mobile devices and found that Apple’s hardware is the fastest in the land. Apple iPhones and iPads were had 8 of the top nine spots for screen latency, including the first 7. In fact, an iPad Pro 10.5-inch using Apple Pencil had the same screen latency as that old Apple //e, at 30 milliseconds. Second on the list, at 70 milliseconds, was iPad Pro 10.5-inches without an Apple Pencil.
The Google Pixel 2L—Google’s flagship smartphone? 110 milliseconds and tied for 12th. Coming in last on the list was the Kindle 4 at a staggering 860 milliseconds. Here’s the chart in full:
Dan Luu’s Chart of Scroll Latency on Mobile Devices
|ipad pro 10.5″ pencil||30||2017|
|ipad pro 10.5″||70||2017|
|huawei honor 8||110||2016|
|google pixel 2 xl||110||2017|
|galaxy note 3||120||2016|
|blackberry key one||130||2017|
|moto e (2g)||140||2015|
|moto g4 play||140||2017|
|moto g4 plus||140||2016|
|samsung galaxy avant||150||2014|
|asus zenfone3 max||150||2016|
|sony xperia z5 compact||150||2015|
|htc one m4||160||2013|
|galaxy s4 mini||170||2013|
|palm pilot 1000||490||1996|
|kindle paperwhite 3||630||2015|
I find all of this fascinating, and it’s a great reminder of two things: the first is that complexity can have a deleterious effect on speed. The second is that Apple’s mobile devices are way better than everyone else’s.