At default speeds, an Opteron 148 and Athlon 64 FX-51 will perform exactly the same - both processors' are Socket 940, clocked at 2.2GHz with a 1MB L2-cache and feature a 128-bit 'dual-channel' memory-controller.
The only difference is that the Athlon 64 FX has full unlocked multipliers, allowing for easier and more flexible overclocking.
Also, the Opteron 148 features three Hypertransport-links(non-coherent, i.e. CAN'T be used for multiprocessing) while the Athlon 64 FX has only one Hypertransport I/O-link(non-coherent) - this is more of a theoretical advantage, tho, as there are currently no motherboards that would use more than one Hypertransport I/O link, if i recall correctly.
should not be confused with Hyperthreading
....unfortunately, both technologies share the same acronym 'HT'.
Hypertransport is a fast, packet-based point-to-point interconnect which connects the CPU to the rest of the system - basically, it replaces the 'classical' FSB on the Athlon 64-platform.
The Opteron 2xx and 8xx series have additional Hypertransport-links for communication between multiple CPUs.
' ">http://www.hypertransport.org/faqs.html#b for more info about Hypertransport
Hyperthreading enables a single CPU to act as two 'virtual'(or 'logical'
It will only offer improved performance if your applications are specifically optimized for Hyperthreading, otherwise there will be little to no benefits - in some cases, you'll actually get slightly less performance when running non-optimized apps.
More info here
AMD's CPUs currently do NOT support Hyperthreading.
The opinions expressed above do not represent those of Advanced Micro Devices or any of their affiliates.
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