In this article we'll review another two AMD Socket AM2 processors: Athlon 64 X2 5000+ and Athlon 64 X2 4800+. These are rather interesting because the former has performance rating higher by 200 points due to its 2.6GHz clock rate versus 2.4GHz clock rate of the latter. But the latter has 2MB L2 cache, which is twice as capacious comparing to that of 5000+! Athlon 64 X2 5000+ has only 1MB L2 (512KB per core), while the X2 4800+ Socket AM2 offers us 2MB cache, classic for AMD's top dual-core. So, the main question is: is it justified to increase performance rating by 200 points only because the clock rate is higher? Especially, if that is accompanied by halving L2 cache?
Hardware and software
* - "2 x ..." means per core
Essential foreword to charts
Our test procedure features two peculiarities of data representation: (1) all data types are reduced to one - integer relative score (performance of a given processor relative to that of Pentium D 805, given its performance is 100 points), and (2) detailed results are published in a Microsoft Excel table, while the article contains only summary charts by benchmark classes.
3D Modelling & Rendering
Athlon 64 X2 4800+, 5000+ and FX-62 formed standard though different "jaggies". It would be naturally to assume that 5000+ outperformed 4800+ less because of higher clock rate and smaller cache. So, a fully-fledged cache of same-clocked FX-62 would make that difference more noticeable.
CAD & CAE
Strangely enough, resource-critical CAD applications preferred clock rate over cache size. We can also see that the system performance bottleneck here is seemingly the graphics card. Because the high 11% dash of A64 X2 5000+ (comparing to 4800+) reduces to 7% (A64 FX-62 comparing to 5000+, respectively.) But the clock rate difference is the same 200MHz. Also significant that usually the fastest Intel Core 2 Duo E6700 couldn't outperform Athlon 64 FX-62 much, thus indirectly proving our assumption.
In this benchmark clock rate advantage provided no benefit to A64 X2 5000+. However, compilers' sensitivity to L2 cache is not a secret (there's even an assumption that it's the 4MB L2 that makes Intel Core 2 Duo win at single-threaded compilation.)
RightMark, like many other "calculators", considers the clock rate almost exclusively, given the architecture is identical. So, AMD processors form nearly identical jaggies.
This is similar in case of Adobe Photoshop CS2...
Such an amusing parity of Athlon 64 X2 4800+ and Athlon 64 X2 5000+: clock rate advantage was negated by cache size. Actually, if you take a look at the results table, you will see that 5000+ did better with short packets, while 4800+ performed better with long ones.
Archivers use much memory to store their large dictionaries, so the victory of slower Athlon 64 X2 4800+ equipped with twice as much L2 cache was natural.
Nearly identical jaggies. The clock rate is the key here.
This is actually similar to 3D modelling and rendering
Nearly identical jaggies between AMD processors. We are already getting used to those.
Such an obvious love for cache makes us wonder if gamers are to actually pay attention to AMD performance ratings in the first place. Otherwise they might end up purchasing more expensive and formally faster processors - only to find out that they are being outperformed by lower-rated cheaper ones.
Efficiency Per GHz
Considering the rather minor difference in performance (and presumably greater difference in price), we can say that Athlon 64 X2 4800+ looks somewhat more attractive than its senior sibling. This mostly has to concern home users (especially gamers!). But, in general, this benchmarking didn't produce any striking surprises. Everything was as expected.
Memory modules for testbeds were kindly provided by
Corsair Memory Russia
Stanislav Garmatyuk (email@example.com)
November 30, 2006
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