AMD’s announcement of the new Sempron processor family has passed without much racket, because the Semprons are mostly well-known Athlon XP models with a new marking and a slightly adjusted performance rating formula. So, the Sempron could hardly hope to become a sensation, although we still dedicated an article to checking out its performance in comparison to its immediate market rival, the Celeron D processor from Intel. Overclockers ignored the new processor from AMD completely since the majority of Semprons are based on long-known and thoroughly-investigated cores Thoroughbred-B, Thorton and Barton. Besides that, it’s not easy to overclock Semprons for the Socket A platform due to their locked multiplier – it is locked to avoid unscrupulous resellers remarking such processors into more expensive Athlon XP CPUs.
The Sempron family, however, isn’t restricted to the now-obsolete Socket A platform – there is a Sempron 3100+ model for Socket 754, the only Sempron to feature the K8 architecture found in Athlon 64 CPUs. Like the Athlon 64, the Sempron 3100+ features a HyperTransport bus and an integrated memory controller with support of DDR400 SDRAM. This makes it an interesting sample to experiment with – if the Sempron 3100+ can overclock well, it can form a good foundation for a low-cost system of some speed. In other words, just the system many overclockers would prefer to use! That’s why we want to dedicate a separate article to the overclocking capabilities of the Sempron 3100+.
By the way, AMD’s policy with respect to the Socket 754 platform results in the company’s pushing it down into the low-end price category. The slowest and low-performance processors with the K8 architecture are released for Socket 754 – besides the Sempron 3100+, they are several Athlon 64 models with ratings of 2800+, 3000+ and so on. But you may remember that the Socket 754 platform used to be the only available for middle-range and top-end Athlon 64 CPUs until the arrival of Socket 939. So now Socket 754 is like an unwanted child for AMD. On the one hand, the company’s trying to sink it down into the bottom of the market as quickly as possible, but on the other hand the current market realities make AMD offer rather fast processors for this platform since there’re quite a lot of computers with Socket 754 mainboards around. Exorcizing the negative aura AMD itself has created around the Socket 754 platform, saying it’s inferior to Socket 939, we’d find that Socket 754 systems are not as hopeless as they seem. Their main disadvantage in comparison to the Socket 939 platform – a single-channel memory controller – is not a very big deal actually. Thanks to the integrated memory controller, the strength of the memory subsystem of AMD’s modern CPUs is in low latencies rather than in high bandwidth. So adding another memory channel does have a positive effect, but the value of this effect is only 3-5% of performance growth. Considering all that, Socket 754 seems to be a most appropriate platform for overclocking. There are inexpensive processors for it, which show good overclockability, while the performance of the platform itself has no artificial ceilings, save for the lack of a second memory channel.