Second, the very architecture of the Athlon 64 suits perfectly for making dual- (or many-) core processors. The CPU core proper is connected to the internal switch (X-bar) that then connects to the memory controller and the HyperTransport bus. Thus, in order to add another core into the die, we only have to add another port to the switch and the two cores will be doing well together. Moreover, the inter-die connection can be high-speed, so that the cores could work with each other’s L2 cache, increasing the value of cache for each of them. This will also reduce the necessity to load data from the RAM somewhat (that’s the longest process, by the processor’s measures). Of course, such contraption will easily scale up in performance with the frequency growth. And again, the natural field of application of dual-core processors is the server market and the market of workstations. It is there that we see numerous applications that make use of multi-processor architectures and are optimized for such systems.
Such processors have potential problems, though. One of them is evident – the heat factor. Two processors must be very hot, so they’ll only become popular with the transition to the 65nm technology, which will appear no sooner than a year. That’s why it is probable that not the fastest, but slower processors will be used in dual-core configurations. Anyway, heat dissipation is not a crucial problem for servers where people have already found ways to keep the hottest server processor cool. Again, dual-core processors are likely to appear in the server market in the first hand.
I’ll also risk a supposition that they’ll be installed into the Socket 940. First, this allows going on with the existing infrastructure as well as investments into advertisement. This will also help to save the users’ money, adding more appeal to this upgrade option for the potential user of the Opteron. This variant also allows setting an appropriate price for this processor. In other words, a price that’s highly profitable for AMD and higher than for the single-core variant of the processor.
The second potential problem lies in the realm of software. Hyper-Threading is quite operational with the Home version of Windows XP as the physical processor is one. With a truly dual-core CPU, you’ll have to buy the more expensive Windows XP Professional, licensed for two CPUs. This is not a big problem if we talk about top-end and expensive CPUs of the series – people who buy hi-end CPUs won’t stop because they have to pay extra $80 for the OS. However, this may become a problem in mainstream and low-end market sectors.
The server market, on the contrary, will certainly embrace such processors due to their much higher performance – as well as dual-core CPUs from Intel, who also dropped a hint about such projects being underway. Moreover, there’s an excellent example of such processor. It is the Power4+ from IBM, which is known as one of the fastest solutions for the server market. In fact, our expectations about dual-core CPUs from AMD (and Intel) are justifiable because many-core CPUs are the alternative way to making systems faster since the linear frequency increase is not always possible. Multi-processor systems can also bear high workloads without a sign of stress, which is their big advantage over single-processor computers.