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There are ubuntu 12.04 32-bit on both machines, results of hardinfo benchmarks:

               Athlon   |  Atom
               X2 TK-57 |  N570
**lower is better:**    |
                        |  
CPU Blowfish:     10.8  |  8.6 (Atom win)
CPU Fibonacci:    5.4   |  7.9
CPU N-Queens:     17.8  |  21.0
FPU FFT:          8.2   |  8.3
FPU Raytracing:   17.4  |  79.4 (OMFG that gap)
                        |
**higher is better:**   |
CPU CryptoHash: 114.82  |  106.38

The mark on Athlon's notebook says that it is ASUS f3ke but CPU specs on Internet-price-lists does not match TK-57 that I got from cat /proc/cpuinfo, Atom's notebook is something so Chinese that I could not even find it on markets year later I bought it.

Why is there such a large difference in performance between the two processors?

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1  
The Atom is Intels ultra-low power netbook processor, it is not surprising a desktop class processor outperforms it. –  Mokubai Jun 1 '13 at 12:23
    
@Mokubai I am confused because Atom has 2 cores by 1600Mhz + 2 virtual cores by 1000Mhz, and Athlod has just two cores with 800Mhz... also in other specs of this cpu's I could not find my answer. –  scythargon Jun 1 '13 at 12:28
    
The TK-57 us a 1900MHz processor see cpu-world.com/CPUs/K8/…. When you see it at 800MHz it is probably in a power saving mode. –  Mokubai Jun 1 '13 at 12:32

2 Answers 2

up vote 4 down vote accepted

As @Mokubai pointed out, the performance and power targets for Atom were significantly lower (though the Athlon is 65nm and the Atom 45nm). Microarchitectural differences include:

  • Atom uses in-order execution, Athlon uses out-of-order execution. Advantage Athlon.
  • Atom has simultaneous multithreading (hyperthreading). Advantage Atom (on most multithreaded workloads).
  • Atom has a 1 MiB shared L2, Athlon has two 256KiB L2 caches (exclusive of 64KiB Icaches and Dcaches). Advantage Atom.
  • Atom has 24KiB Dcaches (shared by two threads when more than two threads are active), Athlon has 64KiB Dcaches. Advantage Athlon.
  • Atom is basically a two-wide design, Athlon has the potential of executing six "integer" µops per cycle. Advantage Athlon.
  • (I think) Atom has a single-ported Dcache, Athon has a quasi-dual port Dcache (using banks, so bank conflicts can increase latency and possibly reduce throughput). Advantage Athlon.
  • Atom has a single memory channel (but faster DDR3 memory), Athlon has two (DDR2) memory channels. Advantage Athlon.
  • Atom runs at 1.66 GHz, Athlon runs at 1.9 GHz. Advantage Athlon.

(I seem to recall that Atom's SSE implementation also provides half-width execution at least for double precision floating-point. I think the Atom has a smaller branch predictor, but that might not be significant in the type of benchmarks used.)

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wow, thanks a lot, I will keep in mind your answer when I would be looking for a new laptop:) –  scythargon Jun 1 '13 at 15:57

The Intel Atom 570 is an 8.5W TDP processor while the TK-57 is a 35 TDP processor. While TDP is not a definite mark of higher processor performance it does imply a higher level of complexity in the Athlon processor.

For processors operating at similar frequencies and using somewhat similar production processes (TK-57 is 60nm, N570 is 45nm) the TDP is a sign that the processor is, in some way, much more complex. It either has more processing units or those units are much larger

The N570 is optimised for low power and from what you have seen is probably lacking some of the extra FPU units that the Athlon has.

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