Earlier this year, my wife and I decided to finish our basement. Great! I thought I could finally set up a real office. I had just one thing to do before my office would become a reality deal with the ghosts of systems past.
Earlier this year, my wife and I decided to finish our basement. Great! I thought I could finally set up a real office. I had just one thing to do before my office would become a reality — deal with the ghosts of systems past.
Over the years I have collected a substantial pile of old hardware. Vintage Pentium II servers in 2U cases, and workstations in big desk-side cases. At one point I was sure I was going to build a cluster out of these systems, but somehow I never got around to it. When you have a big empty basement, why not fill it with old hardware and build a cluster? Isn’t that what people do these days?
In any case, these systems were eBay orphans — not even worth the shipping cost, not worth testing, etc. I had checked into donating them, but they were just a little too old and slow. In addition, the systems were “white box,” unbranded systems. (Why are they still called “white box” systems when they’re in black cases?) The only solution was the recycle bin, but that meant separating the metal from the electronics. Not a problem, with a few screw drivers, some wire cutters, and the help of my teenage daughter, we quickly had a pile of metal and a pile of components.
While we were dismantling these systems, I started thinking about the fact that these systems were pricey and fast not so long ago, and now they were getting pulled apart like cheap toys headed for the trash heap.
I guess that’s the way of cluster technology. The new generation processor forces multiple old ones to become obsolete. A single new quad-core processor can easily replace four older processors, motherboards, power supplies, etc., and use less power! Out with the old and in with new. Like most old computer hardware, the boot heel of technology finally landed on these systems.
But will the same thing be true of the bright and shiny multi-core systems we’re buying today?
Let’s look at a hypothetical situation. The systems I recycled had 400MHz Pentium II processors (single core). Of course, one of today’s 2.3 GHz dual-core processors is running at with a clock speed that is six times faster. When it comes time to get the latest and greatest, will the future bring a 14 GHz dual core processor or will it bring an 3.0 GHz eight-core processor?
From what I know about physics, I’m betting on the eight-core processor. Notice that the core count is increasing quickly and the clock speeds are creeping up slowly. Therefore, the actual performance of an MPI program running on eight older dual-core processors (16 cores total) may not be that much slower than two new eight-core systems. (And yes, it all does depend on the application.)
In other words, newer processors will be adding cores similar to what I already have. My old cluster is kind of like the new cluster only the new one has more cores. In the past, it was about clock speed, now it is about cores. Multi-core actually gives clusters a longer effective lifetime and keeps boot heel of technology at bay just a bit longer.
In a strange kind of way, I find this to be one of the major advantages of multi-core. I doubt people are going to stop buying new hardware, but the old hardware will continue to have some utility — much more so than in the past.
Basically it means more cycles for more problems. I like that option. My only remaining issue is where to start stockpiling those dual-core machines. I can’t keep them in the refinished basement and expect to stay married.
I do have some room in the shde out back. I just have to move the boxes of fans, power supplies, cables, power cords, and PCI cards I just pulled from old systems. Maybe I’ll start a museum.
Douglas Eadline is the Senior HPC Editor for Linux Magazine.