Yes, something is definitely holding back the AMD systems. If you look at the synthetic benchmarks comparing the P 965 at stock speed to the i7 920, the P is a tiny bit slower at floating point arithmetic, and slightly faster at integer performance. As i believe it won out in terms of instructions per second. So basically, they are neck and neck in terms of ability to turn through calculations (AMD has 28% clock speed advantage what do u expect).So why is Intel winning?
Its all about the cache and the memory bandwidth baby! The Intel chip is running at much fuller capacity, while the AMD chip is constantly 'waiting' for information. This is made even worse when u look at the architecture of the 2 chips, i am sure. Furthermore, the ability to run 2 threads on a single core is the finishing blow. By running 2 treads simultaneously, u only need to process each one at half speed, meaning u have twice as long to do it.
Let me give AMD and their engineers some advice, based on carefully studied figures. First 2 pieces of information that my conclusions are based on:
1) I heard rumors of a 2.8 GHz quad (L3 cache reduced/removed) with a 65 watt TDP.
2) The bump from 2mb L3 cache in Phenom 1, to 6mb L3 cache in phenom 2 only gave ~4% performance increase according to AMD engineers.
3) The increased cache resulted in a transistor increase in the range of ~60-75% (can't remember exact figure).
I now draw a conclusion:
The 2.8 GHz quad with reduced L3 Cache should (fingers crossed) have virtually the same performance, but with a 65 watt TDP, while being much cheaper to make.
I now make a suggestion:
Build a 6 or 8 core version of this CPU.
The power consumption/cost/performance should be (approximately) as follows
1) ~95 watts for 6 core, & ~130 watts for 8 core
2) 6 core chip cheaper then PII 940 (3.0 GHz quad), 8 core chip same as P2 955. (reduced L3 cache & clock speed help price)
3) Single threaded performance equivalent to PII 920 (2.8 GHz quad), multi thread performance ~30% faster for 6 core and ~55% faster for 8 core.
One final piece of the puzzle; new motherboard with better memory support. May i suggest Tri or Quad channel DDR3 1333?
Based on the above i would choose the 6 core chip as the clear winner. 95 watt TDP, 2.8 GHz, 6 cores and inexpensive. Only downside is reduced cache which will do virtually nothing to performance.