AMD Sempron 3100+
To further complicate matters, the name Sempron also applies to a solitary processor whos innards are taken from the impressive Athlon 64 range of processors. Step forward the Sempron 3100+.
A familiar sight over the past year or so, AMD's heatspreader-clad Athlon 64 processors have taken the performance fight to Intel ... and won. The Sempron model, however, isn't quite able to match the Athlon 64's specifications; it's regarded as a budget processor, after all. Initial 754-pin Athlon 64 processors carried 1024KB of L2 cache. High on-chip cache levels infers ballooning transistor counts and higher costs. That's why the majority of present Athlon 64 CPUs have traded higher clock speeds for lower cache limits. With the Sempron 3100+ retailing at around the £85 mark, AMD's had to introduce cost-cutting measures. Quite predictably, the Sempron 3100+ carries 'only' 256KB, and can be thought of as a lesser Newcastle core.
AMD's also decided to distinguish its Athlon 64/FX and 754-pin Sempron line further by lopping off the former CPUs' 64-bit extensions and addressing capability. Presently, that's not that much of an issue. 64-bit OSs and compatible software are thin on the ground (cue the rampaging Linux crowd). However, a lack of 64-bit compatibility will impact on its attractiveness in the future. How soon that will be is anyone's guess, really.
I've discussed the negative aspects of the Sempron 3100+'s architecture in relation to the faster, more expensive Athlon 64s. It, though, does carry the juicy on-chip low-latency memory controller and HyperTransport link that's proved so effective, performance-wise, for the Athlon 64s. It also beats out Socket A Semprons by having the innate ability to run with DDR400 memory, albeit in single-channel form. In short, the Sempron 3100+ provides Athlon 64-like performance at hither-to unseen price levels.
As there's only one current Socket 754 Sempron, its specifications are easier to understand.
Socket 754 form factor
1.6GHz HyperTransport Link
130nm SOI (Silicon-On-Insulator) manufacturing process
Integrated memory controller with a DDR400 DRAM-compliant controller
128KB L1 cache, 256KB L2 cache
~70m transistor count
| Model name | Clock speed | Price (approximate) | Sempron 3100+ (S754) | 1.8GHz | £85 |
AMD, I feel, is justified in raising the model numbering on the K8 Sempron 3100+ even though it runs 200MHz slower than the Socket A Sempron 2800+. The low-latency integrated memory controller, for one, plays a large part in raising clock-for-clock performance. The one problem that's apparent if we're thinking solely from a budget point of view is the current lack of really inexpensive S754 motherboards. It's difficult to source sub-£50 boards. Combine that with the £85 asking price for the sole K8 Sempron and one begins to encroach in on Pentium 4 and Athlon 64 territory.
