We have accumulated quite a large suite of tests for our Suneido applications. It takes about 100 seconds to run them on my work PC.
I happened to run the tests on my iMac (on Vista under Parallels under OS X) and was surprised to see they only took about 50 seconds - twice as fast! My iMac is newer, but I didn't realize it was such a big difference.
One of my rules of thumb over the years has been not to buy a new computer until I could get one twice as fast (for a reasonably priced mainstream machine). No point going through a painful upgrade for a barely noticeable 15 or 20% speed increase.
I usually like to go for the high end of the "normal" range. Buying the low end reduces the lifetime of the machine - it's out of date before you get it. And I'm not going to try to build the "ultimate" machine. You pay too big a premium and have too many problems because you're breaking new ground. And by the time you get it, it's not even ultimate any more.
Doubling the speed has gotten tougher over the years. CPU speeds have leveled out and overall speed is often limited by memory and disk since they haven't improved as much as CPU speeds.
The trend now is towards multi-core, which is great. But when you're still running single-threaded software (like Suneido, unfortunately) then multiple cores don't help much. And the early multi-core cpu's tended to have slower clock speeds and could actually perform worse with single-threaded software.
It's also gotten tougher to judge speed. In the past you could judge by the clock rate - 400 mhz was roughly twice as fast as 200 mhz. (I'm dating myself) But now there are a lot more factors involved - like caches and pipelines and bus speeds. And power consumption has also become more important.
Anyway, my rule of thumb has now triggered and it's time to look for a new machine. I decided I'd look for something small, quiet, and energy efficient yet still reasonably fast (i.e. as fast as my iMac). I looked at the Dell Studio Hybrid and the Acer Veriton L460-ED8400. The Dell is smaller and lower power but more expensive and not as fast - it uses a mobile cpu. The Acer is not as sexy looking but it's faster and cheaper. Both have slot loading DVD drives. For a media computer the Dell has a memory card reader, HDMI output, and you can get it with a Blu-ray drive. The Acer has gigabit ethernet and wireless built in.
Neither machine came with a big enough hard drive. These days I figure 500gb is decent. The Acer only had a 160 gb drive but at least it was 7200 rpm. The Dell offered 250 or 320 gb drives but only 5400 rpm. It seems a little strange considering how cheap drives are.
Ironically, I now find I need more disk space at home (for photos and music) than I do at work. Source code and programs are small. And my email and documents mostly live in the cloud.
I ended up going with the Acer plus upgrading the memory to 4 gb and the drive to 500 gb for about $1000. I paid a bit of a premium to order from a company I'd dealt with before. You can get cheaper machines these days, but it's still a lot cheaper than my iMac.
There are probably a bunch of other alternatives I should have looked at. But I don't have the inclination to spend my time that way. And the paradox of choice tells us that more alternative don't make us happier, in fact often the opposite.
I've also been wanting to run Vista. I know, the rest of the world is trying to downgrade to XP, but I've been running Vista on my Mac (under Parallels) and I don't have a problem with it. It's got some good features. I'm not a huge Windows fan to start with. I was thinking about trying Vista 64 but these machines didn't come with it and I hear there are still driver problems. So to keep things simple I'll stick to Vista 32.
One challenge will be to swap in the bigger hard drive. I assume Windows will come preinstalled on the hard drive in the computer and I won't get an install disk. Normally you'd plug the second hard drive in and copy everything over. But I suspect these small computers don't have room for a second drive. I should be able to plug both drives into another bigger machine that can take multiple drives and do the copy there.
It's always exciting (for a geek) to get a new machine. Of course, the part I'm trying not to think about is getting the new machine configured the way I want it and all my files moved over and software re-installed. Oh well, it's always a good opportunity to clean up and drop a lot of the junk you accumulate over time.