Understanding processor performance across generations

[gx240]

I'm trying to understand what specs account for the difference in performance between Intel processors of different generations/architectures.

For example, look at the i5-7500 and the i5-4670. Both have 4 cores, 4 threads, base frequency of 3.40 GHz, and max turbo frequency of 3.80 GHz.

Of course I can assume that the i5-7500 is going to be substantially faster than the i5-4670, because it was launched almost 4 years later, but what specs actually account for the increased performance of the i5-7500?

Is it the smaller die size? The bus speed? Something else? If you didn't know the release date of the chip or its generation, what specs could you look at to predict its performance relative to another processor?

 

[ShadyHamster]

I wouldn't say there is a substantial performance difference between those 2 CPUs.
The i5 7500 would be 5-10% better, depending on what you're doing.

 

[rhoban]

There are things which don't shoe on spec sheets.

The architecture matters.
The smaller die size means lower temperatures and less power consumption. Which also means you can get more performance while still maintaining the 65W or 95W TDP.

IPC (instructions per core) is something that affects performance. IPC is a spec that isn't listed anywhere.
Intel generally has a better IPC than AMD.
Frequency is also somewhat of an indicator, but not always.
Cache is another factor.

My suggestion is to look for comparisons online. You should be able to find pretty much anything.