Intel’s Innovations Efficiency and Their Comparison with AMD x86-64

The additional Prescott instructions make the whole instruction set somewhat well-shaped and complete. We can live with it for a long time, until some radical changes happen. Of course, we might wish to have more registers, but this would be hard to do without losing in compatibility because of restrictions of the x86 instructions format. But there are a lot of little dainties: like the effective fisttp conversion commands. Automatic generation of SIMD-optimized code has also become much simpler.

The upcoming processor may have only one weak spot, besides (possibly) the price. It’s the long pipeline and, accordingly, a strong “dislike” to conditional branching. The longer pipeline seems to be an unavoidable evil on the way to higher frequencies.

Overall, I think Prescott is going to be the most perfect product Intel issued in the last few years. I am not talking now about its power supply and cooling requirements – we just hope there won’t be any problems here. As for the price, there is every reason to think that it won’t be too high. Look at the size of the L2 cache: it is 1MB. What would the next Celeron be like then? Is it going to have 512KB L2 cache? This isn’t our good old Celeron – it’s just a monster! Most applications don’t need more than 256KB of cache, so there is a big reserve for prime cost reduction. The transition to the new technological process does promise to be profitable.

There is one circumstance, however, which can boost the processor price: no competitors. We’d like to view the new 64-bit processor from AMD, Athlon 64, as a strong rival to Prescott. We guess you already know a lot about its technical peculiarities and strengths, otherwise refer to our AMD Athlon 64 article, which covers this topic in really great detail. And now we would like to dwell upon its attractiveness to software developers.

AMD has finally implemented SSE2 support. Now Intel processors won’t have an “a priori” advantage in SSE2-using applications. Athlon 64 features compatibility and 64-bit work modes, the latter brings all the advantages of the AMD x86-64 architecture. In the compatibility mode, the new processor looks to the software developer like a Pentium 4 with screwed up 3DNow!. Moreover, it is free from certain drawbacks like the terrible execution of non-SIMD-optimized code and the dislike of branching. We guess the new AMD processor is going to be a worthy rival to Pentium 4, of course, if it ever reaches the boxing ring.

We may venture a prediction that Pentium 4 will need a considerable frequency advantage to equal the new Athlon in integral benchmarks that comprise a wide range of applications. Moreover, there are a lot of benchmarking results of Athlon 64 samples on the Web that show its twice as high performance-to-frequency coefficient over Pentium 4.

But what about the exclusive 64-bit mode? Besides the recompilation of programs, there are three main things: twice more registers, 64-bit arithmetic and over 2GB virtual address space of an application. 64-bit arithmetic is a good thing by itself, but has a narrow usage scope in desktop systems; most applications are quite well with 32-bit one. AMD pointed out another actual field of application of 64-bit integer arithmetic. It is a much faster execution of some cryptography tasks.