Why does your president need such? Cameron popped over to the States the other week, he flew back in business on BA, not even in first (my wife would not be impressed if I sent her in business). He has his finger on 180 nuclear warheads, but seems to be able to do that from a civilian plane just as well.

Good luck ever actually getting rid of it, considering it is what every *nix gui app runs on. Even if the switch to Wayland happens, most people will still be stuck with using XWayland constantly for a decade.

Slow filesystems access disks, and store data, less efficiently. It's a pretty big deal.

Whaa? I'm not talking about the FS using memory and CPU, but that it is slow for accessing data off the disk, which is a common bottleneck.

OSX is slow as balls compared to Linux, on Apple hardware no less.

benchmarks.

Postmark on Ubuntu on an Air is THREE TIMES as fast on Ubuntu as Linux. Probably because HFS is an abomination. Even graphics accelaration is much better with Linux. MAFFT is more than twice as fast.

Only for python packages. apt-get/yum/etc are far easier and more reliable than half-assed package managers like Homebrew.

HCCI engines are a really cool technology, but very hard to do.

Efficiency of internal combustion engines is related to the compression ratio - the ratio of the combustion chamber from largest to smallest capacity.

Gasoline engines usually have a compression ratio around 9:1. Higher, and the compressional heating combined with the heat off of the walls can cause "knocking," which detonation of pockets of fuel/air away from the flame front from the spark plug. Engines with premium gas can run higher compression ratios. Higher-octane fuels can be compressed more without burning, but of course there is no benefit to running it on engines rated for regular.

Diesel engines run ratios of around 17:1, resulting in much greater efficiency. Diesel engines of course don't have spark plugs. The fuel is injected just before top dead center, where the air is compressed maximally. This is in contrast to a gasoline engine, where it is well mixed with air before entering the combustion chamber. Due to compressional heating, it spontaneously combusts very quickly, much faster than the combustion in a spark-plug-ignited gas engine.

HCCI well-mixes the air and gas upon intake, but ignites by compression like diesel. This gives diesel efficiency. In addition to the better compression ratio, HCCI controls power by the amount of fuel injected, like a diesel. Gasoline engines use a throttle to choke off the air supply, which induces losses because the engine has to work harder to pull air at lower power. That's how engine braking works, and also why diesel trucks use a separate "jake brake" to use the engine to brake.

It must run under a leaner mixture. It's really hard to have complete burning of fuel, and avoid knocking. That's why it has to be very carefully computer controlled based on temperature and such.