Articles: CPU
 

Bookmark and Share

(14) 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 ]

Now, let’s take a look at the other end of the processor scale where the Opteron resides. The evolution of this processor seems predictable: x50 models will come out (made by the 130nm + SOI technology), followed by higher-frequency models, if necessary.

It’s more interesting to examine the rumors that AMD emits to the question “Why does AMD have no analog of the Hyper-Threading technology?” The processor from Intel wins some tests exactly due to Hyper-Threading. In other words, AMD’s realizing a similar thing in its processor would reduce the last trump in the opponent’s hand to naught.

There seem to be two reasons. First, the micro-architecture of the Athlon 64 differs greatly from that of the Pentium 4, making it very difficult to implement an analog of Hyper-Threading (the decoder and some other CPU units would require a complete overhaul). The Pentium 4 processor was developed with this technology in mind (for example, the trace cache was invented for that, too) and it does bring a perceptible performance gain. The Athlon 64, without a total redesign of the core, won’t get the same performance gains as the Pentium 4. The reason is in the very micro-architecture of the Athlon 64. One of the main problems with the Pentium 4 is that its execution units are often idle, mostly due to the high clock rate of the processor and the peculiarities of its decoder. Accordingly, the introduction of Hyper-Threading technology allows masking data load latencies and increase the efficiency of the CPU. This problem is not as acute with the Athlon 64, since its execution units are not idle often. And the problem of loading the execution units is solved differently there.

The second reason has been voiced by AMD spokesmen at one press conference: “it’s better to release a truly dual-core processor, rather than make one processor pretend it is two”. Really, two physical processors will be faster than one physical processor that pretends to be two logical CPUs. Really, it’s better to be healthy and rich than ill and poor. AMD shouldn’t forget, though, that Hyper-Threading does provide some advantages to the competitor processors in some applications, especially in a multitasking environment. So this technology should receive some kind of answer. Dual-core processors would make a good and effective response.

If we take that AMD is working in this direction, then every piece fits into the puzzle. First, on transitioning to the 90nm+SOI technology, the processor square (although with just 512KB of cache) is 102 sq. mm. Thus, we can integrate two processors into one die and the resulting chip would be about 200 sq. mm. This roughly corresponds to the surface size of current Athlon 64 CPUs. This size is acceptable for hi-end and server processors.

 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 ]

Discussion

Comments currently: 14
Discussion started: 04/02/04 08:52:03 AM
Latest comment: 09/28/05 12:54:13 PM

View comments

Add your Comment