Is the AMD FX 8 series really 8 cores?

[Huyster]

Hi,

First time poster here.

I've seen people talking about how multithreaded programs run better on cpus with more cores, such as the FX 8 series cpus, and recommending AMD cpus over intel's quad core i7's for this particular reason. I am also aware of how AMD market these cpus as being the "industry's only 8 core desktop processor". However, looking at wikipedia (I know its not the best source of information at times), I see that the 8 series cpus only have 4 physical cores and 8 "integer clusters". Does this mean that these cpus are the same as intel's quad core cpus which have 8 threads, or is this completely different from hyperthreading?

This is the wikipedia page I am referring to: http://en.wikipedia.org/wiki/List_of_AMD_FX_microprocessors

Thanks

[Glenwing]

The FX architecture does have 8 physical cores. They are organized into 4 modules, each module consisting of 2 cores with a shared L2 cache. Because each pair of cores shares resources, it's not quite as good as a true 8 core, but better than an Intel quad-core with hyperthreading (as far as performance gains over a quad core of the same architecture, not necessarily in a head to head competition, since Intel gets better instructions per clock).

Some people say the AMD's 8 core processors are 4 modules which is like 4 cores with AMD's version of hyperthreading, but this is not really correct. It doesn't perform as well as it would if there were 8 standalone cores, but a fair bit better than if they were 4 cores hyperthreaded.

[Huyster]

Thanks for clearing that up so quickly! I feel like I'm a lot more informed on this 8 core business. Thanks Glenwing

[hiyayhi]

The FX 8350 is comprised of 4 piledriver clusters, each contains 2 "cores" this makes it physically an eight core but technically a four core, it is different from the i7 which is four cores and has four virtual cores to make eight threads. If you were to stick eight of the i7 3770k's cores all together it would perform better than an 8350 but because the 8350's cores are technically physical it will usually beat the i7 3770k in heavily multithreaded applications.

I hope this answers your question :D

[Glenwing]

I just said that :P

[TechFan@ic]

The FX 8350/8320 8150/8120 chips are true 8 core CPUs, there is no need for me to repeat what glenwing said, because it's spot on.

Those CPUs have 8 actual cores with a level of resource sharing, a very simple yet clear evidence that supports this is that you can run any x86 program on one core out of the 8 by disabling 7 cores and just leaving one on.

This is what overclockers do to achieve OC records.