Originally Posted by welchgc
Hi Which is the better CPU: AMD TL-56 (Turion 64 X2, 1.8GHZ, 1MB Cache) or Intel T5250 (Core 2 Duo, 2MB Cache, 1.5GHz, 667 FSB) I have the choice of either, notebook is going to run vista and be used for business/media (no gaming) Thanks for any help.
I'd pick the TL-56 as it's roughly as fast as the T5250 but runs cooler and is backed up by much better chipsets than the Intel 945GM that ships with the T5250. Plus, the AMD-powered unit will be considerably less expensive than the T5250-powered unit. I'd recommend the Core 2 Duo only if you need a low or ultra-low voltage chip with reduced thermal outputs OR you want performance greater than what a 2.00 GHz Core 2 Duo will give you as that's about what the top-of-the-range 2.40 GHz TL-66 can pull off. And to the guy who said that more cache is better: not necessarily and also AMD and Intel CPUs have very different cache needs. First, more cache is not always better. Remember the Pentium 4 Prescott 500 series with 1 MB L2 versus the 600 series with 2 MB? The 2 MB L2 cache was slower than the 1 MB L2 cache, so many programs ran faster on the 500 chips than the 600 ones. That is a very rare case as more L2 cache is generally better. But HOW MUCH better varies across CPU brands and architectures. There is generally a certain amount of cache that a CPU "likes" and sees significantly reduced performance if it has less than that and also small gains from putting more cache on the chip. Secondly, Intel and AMD chips are quite different on the inside and thus have different amounts of cache that they "like." AMD CPUs have their memory controller directly on the CPU, whereas Intel CPUs have their memory controller on the northbridge (a separate chip) and they shuffle that data over the frontside bus, aka FSB. AMD's approach results in less time between when the CPU asks for data from RAM and when it gets it as the data passes directly from the memory controller to the CPU cores and doesn't have to go through the FSB. Thus, memory accesses cost Intel CPUs more in terms performance than they do for AMD chips. So Intel has prefetching, which is the chip guesses at what data it thinks it will need and has that data fetched from RAM to the L2 before it needs it. This requires more L2 space than if the prefetchers weren't there, but can increase performance if the prefetchers guessed right, as L2 is much, much faster to get data from than RAM. Intel's Core Duo and Core 2 Duo chips also have a much different cache design than AMD's Athlon 64 X2/Opteron/Turion 64 X2 chips do. The Core/Core 2 chips have one L2 shared between two chips and this L2 is the way that Core 0 will pass data to Core 1 if Core 1 needs it and Core 0 has it. AMD's dual-cores have separate L2 caches for each chip and the data from Core 0 is requested over an internal data path called the crossbar and transferred over the memory controller's data channel. Also, Intel has the contents of the L1 mirrored in the L2 (inclusive cache) while AMD does not do this (exclusive cache.) These differences mandate that Intel CPUs have much larger L2 caches than AMD chips do to achieve the same relative performance levels. A 2x512 KB L2 Turion 64 X2 has plenty of L2 cache. AMD makes desktop chips with 2x1 MB L2 and these chips outperform the 2x512 KB chips by nothing in most programs and by 5-7% in a couple of programs. Core 2 Duos with 1 MB shared L2 lag behind the 2 MB L2 chips by 10-15% and the 4 MB chips are 5-10% faster than the 2 MB chips. So not only do AMD chips need less cache than Intel chips, they are also less sensitive to changes in cache due to their memory controller.