Hardware Update One

posted 13 years ago by Ben Cordero

Recent Upgrades on Juniper

IOMMU: I shelled out for the crosshair IV. The ASUS motherboard based on the 890FX chipset. If an upgrade is to feel like an upgrade, then why not a RoG setup.

New Capabilities

With modern hardware, a kernel compilation takes 10-20 minutes (depending on how much I removed from a stock genkernel), X takes 20-30 minutes, and KDE still takes a few hours. It wasn't so long ago that a full (graphical) gentoo install would take a week or two, minimum.

Now, I can have a usable gentoo system running from stage3 in under an hour. A working machine up in two (X, opera, fluxbox etc), and leave the rest of the day for updates and extras to emerge in the background c.f. KDE.

What was once a traditionally computationally and I/O bound task, is no longer a problem when you have 6 physical cores to emerge packages (all with /var/tmp/portage in RAM for that extra burst of speed). I can even boost that to 'make -j11' with parsley's 4 logical cores. So, I find myself turning to other problems to throw parallel processing power at.

With great power comes great cooling

New Usage Patterns

When emerging many packages (think about what happens when KDE releases a new minor version), I commonly seen that processor utilisation peaks and dives. A single core is loaded up as ./configure scripts check the system for the umpteenth time in series, then make -j11 hits and the console output turns to a mist of white scrollback. The feeling of the awesome parallel power is short lived however, and we're back to a single threaded install phase I/O bound by the Hard Disk and we thank the RAM gods for a job well done. Portage resolved what is to be the next ebuild to munch, and the cycle starts over again.

I play other games, such as doing runs of low-bit rsa keys. 256-bit keys are trivial, and 512-bit keys are feasible. 1024-bit keys are out of my league, but I'm just doing this with spare clock cycles.

What I have discovered is that finite and feasible computations (compiling and factorizing) probably don't make the best use of a multicore machine. I decided to partition up the resources instead, dynamically allocating them to where they would most be needed.

New Directions

Next Post, Where I find VMWare and what's so special about an IOMMU.