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Which Processor Is Best For Real-Time Computations?
NoWhere Man asks: "For the longest time my friends and I have been arguing over which processor is better (Intel or AMD). I know this is an ongoing battle everywhere as well, but it took an interesting turn the other day. Which processor would be better for realtime, high end mathematical computations? AMD's Athlon? P3 Xeon? or Dual Processors? If anyone could recommend system specs, keeping it cost effective at the same time, it would help."
Are you referring to hard real-time applications? If so, you don't want an SMP system. Infact, you don't even want a system with a cache. Why? Because hard real-time applications optimize for worst case performance. Caches do well to improve average case performance, but usually hurt worst case performance. Thus, hard real time systems usually don't use caches.
In general, real time apps (even soft real time, like video or audio decode) are concerned more with low latency then high throughput. As a result, you aren't going to want an SMP system. The complex caching systems in SMP's is going to make performance even *less* predictable which is precisely *not* what you want for real-time.
If you just want a really fast media-cruncher, then you don't want to be running x86. If you're serious, you'll go for something like an Alpha, that will smoke any x86 in FPU. Besides, if you really want to get into real time media processing, you are going to need a great deal of bandwidth, and commodity x86 hardware isn't going to get you where you need to go.
If what you really want is a budget box to run games on, then get an Athlon. A quick review of any games site in existence will tell you that Athlons beat Intel's offering in every regard these days. There's no reason to bother Slashdot with such common questions. Any of the DIY gamer sites will have a host of articles with benchmarks running Quake or Unreal or whatever it is kids play these days.
I get the impression that this post is from someone who doesn't understand real time computation, and just through that phrase in there to make their question sound more sophisticated.
--Lenny
If you're doing Signal Processing or DSP-related tasks, the 7400 smokes. ;)
As always, it all depends on what numbers you're crunching, and for what purpose. The vector processing in the 7400 is pretty sweet if done right, and one of the Linux PPC variants has full support now.
Just a though to get away from x86
Pope
It doesn't mean much now, it's built for the future.
No, really, it is. What does real-time have to do with this? You can't solve an arbitrarily complex mathematical problem in a bounded amount of time. And that's what real-time is, bounded. Real-time has nothing to do with speed in the sense that this question is phrased. An example: A given problem must be solved in 15 seconds or less. Chip A can solve the problem in 1 second most of the time, but will take 30 seconds every once in a while. Chip B will usually take 5 seconds, but never more than 10. Guess which chip is can give you a real-time guarantee? That's right, even though Chip B is usually slower, it is the one you pick.