I'm trying to decide between 2 Toshiba laptops: L755-S5356 ($530 or so in a store) and L770D-ST5NX1 from Toshiba online @ $70 more: the latter has 6G/640G/17.3" vs 4G/500G/15.3". The main doubt I have is how the CPUs/cores trade off: a quad-core A6-3400M (2.3GHz, 4MB cache) vs i5-2430M 2.4GHz (3 GHz with Turbo boost) 3MB L3. I think the A6 memory spec refers to L2 and there is no L3 cache, but I'm no expert clearly, and welcome your clarification.
Which one to get is going to be determined by what programs you use. If you have any really CPU intensive programs that don't require a lot of graphics muscle, the i5 is the better choice, as it is much faster than the APU on CPU intensive task. The i5 laptop has Intel's HD 3000 integrated graphics. The A6 3400m has the Radeon HD 6520G integrated graphics. The AMD IGP is significantly faster in gaming than intel's offering, though on modern titles it only will do low settings, but you have a much better chance of getting playable framerates than you will out of intel's IGP. If you want to do some light gaming on this laptop and you don't need a lot of CPU horsepower for anything else, the A6 maybe be a better choice.
I have a very similar laptop from Toshiba myself with the A6 and it performs all the basic office tasks, web browsing and video playback just fine. If that's all you're doing plus maybe some light gaming it's a good choice. For general tasks such as that, the i5 won't be any faster, you're going to be bottlenecked by hard drive speed long before CPU speed becomes an issue in those applications. You wouldn't see any real difference in day to day use with the i5 over the A6 unless you got an SSD for the laptop.
In terms of CPU processing power, there is no comparison between the Llano A6 and the Core i5. The Intel CPU will completely dominate Llano.
AMD's Phenom II / Bulldozer CPU cores do not directly compete with Intel's Core i CPU series. Instead they are comparable to Intel's older Core 2 Duo / Quad CPUs. When compared to the Core i series CPUs, you are talking about an average of 20% disadvantage in CPU processing power.
The Llano APUs have a CPU core that is based on the older Athlon II CPU core. It has been tweaked to improve performance a little bit. but against Intel's latest CPU cores, Llano is around 25% slower on a clock for clock basis.
The good news is the GPU cores in Llano APUs are a little more powerful than the Intel HD 3000 graphics core in the Sandy Bridge series. Basically speaking, the Intel HD 3000 is equal to a desktop Radeon HD 5450 card. The GPU cores in Llano APUs generally ranges from a desktop Radeon HD 5550 to a HD 5570 video cards (approximately) depending on the model. The GPU core in the A6-3400m would be somewhere in between.
There are games that make use of 4 cores but the graphics is what really makes the difference not the processor when it comes to gaming. Though they may look similar these laptops are very different and as stated the Intel processor is a huge amount better and the AMD graphics are hugely better. If you want to play games like Crysis 2 and Skyrim then the AMD graphics are essential (and will still only play it on low settings) to make it even playable.
Thank you for your very informative answer. Would greatly appreciate it if you could throw light on something: the AMD A6 (on paper) offers 4 cores, whereas the Intel i5-2430M is listed as having 2 cores (and 4 'Threads'), yet the latter blows away the former? IOW, 2 extra cores do not help? More cores means potentially more parallelism for CPU-bound loads -- is that correct?
Yet, for everyday and even light gaming use it looks like either configuration is ok as it looks like the GPU becomes the determinant/wait-point when all cores are fully used.
Appreciate your clarification. Thanks again.
<use with the i5 over the A6 unless you got an SSD for the laptop.[/quotemsg]