AMD Intel (GHz)

[jdlenke]

In the past i've seen several pro amd and pro intel posts and what really confuses me as a system builder is the performance numbers. I've always leaned toward intel chips because the ghz numbers were always obvious and i know for a while there amd followed suit but then at some point they went off the track and now i can't figure out marketing wise how to tell a customer or myself for that matter that a 1.2ghz amd is better than a 2.8 ghz intel. someone shed some light on this for me.

[Platypus]

And Intel have made it more complex by now using a performance oriented model numbering system independent of clock speed.

Unfortunately, there is really no ironclad way to identify performance equivalence, even within manufacturer's CPU families, let alone between manufacturers.

Where all CPUs shared the same architecture, performance could be closely tied to clock speed. Really, this started to unravel with the 486, when some second-source chip manufacturers produced chips with small caches, eg the IBM Blue Lightning, giving lower performance for the same clock speed in some circumstances.

As the architecture differences between manufacturers, and among manufacturers own chip lines, increased, clock speed meant less about overall performance, and the comparison changed depending on what the CPU was doing.

It's a common misconception that AMD's "speed" designation is intended to rate an equivalence to an Intel P4. While it may provide a guide in this direction, it was actually intended to address a difficulty AMD had within its own Athlon range. The original Athlon was identified by clock speed, then the successor was re-designed with a more efficient architecture, thus delivering greater performance for a given clock speed. The clock speed ranges overlapped, so AMD had the problem of two CPUs of the same speed, with different prices and performance. So the Plus concept arrived - the speed AMD calculated the original Athlon would have to be run at to give similar performance to the new chip. The Athlon XP 1600+ at 1.4 GHz delivered performance like an original Athlon at 1.6GHz.

Intel had a similar problem (reversed) between the Pentium3 and the P4 - speed for speed, a PIII out-performed a Williamette P4. They simply lived with this. And they still have a similar situation with the Pentium M range, where much slower clock speeds can match faster P4 chips in some circumstances.

So I don't know what the answer is. Maybe it's a bit like cars, their top speed is only one part of the equation, there's also handling, acceleration, fuel economy, seating capacity... Although it's probably easier for prople to see this than it is with computer specifications.

[SuperSparks]

I couldn't put it any better if I tried. I find the best thing to do these days is to study the various benchmarking charts that are around. This is always a good one to start with:

http://www.tomshardware.com/2005/11/...u_charts_2005/

[Train]

And DO take into consideration what you might intend to do with the computer from the very beginning!