Good evening dear tek syndicate community.
This post should be an interesting one for all of you, especially for those who´re using an AMD FX-8120/8150 CPU.
I´ve done quite some research on the Bulldozer architecture. It is, as most of you should know, module-based.
Just to make sure that everyone, who reads this, is up to date I am going to explain it.
The Bulldozer line-up consists of 3 CPU variants. There´s the FX-4000 series (Quad-Core CPUs), the FX-6000 series (Hex-Core CPUs) and finally the FX-8000 series (Octa-Core CPUs).
The 4000 series is a dual module CPU with 2 cores per module.
The 6000 series is a trippe module CPU with 2 cores per module.
The 8000 series is a quad module CPU with 2 cores per module.
Take a look at this picture beneath.
Here you can see how a Bulldozer module is designed.
As you can clearly see each core has its own INTEGER SCHEDULER and its own LVL 1 CACHE.
However, the rest of the resources are being shared. Those are the LVL 2 CACHE, the FPU SCHEDULER, the FETCH and DECODE UNIT.
This is also the main weakness of the processor. This architecture literarely chokes the cores.
In heavy multithreading the CPU is good but in light threaded or even single threaded apps it simply fails. The reason is the sharing of resources.
Many people bought this processor with the expectation of getting a potent gaming CPU which it is not thanks to it´s design.
The 8000 series is special one thanks to its 4 modules.
Now, before I continue I want to apologize to Logan for posting this thread and sort of being a buzz kill as I can imagine that he´d want to add this in one of his upcoming videos. Maybe not, I don´t know. I´ve talked with him about this idea of mine via PM on youtube a couple of days ago. He was interested and promised to check it out and inform me about test results.
Anyways, let´s move on.
Let´s say you´ve bought an AMD FX-8120/8150 and in order to play Battlefield 3 just to notice that it´s not performing very well. Well, that´s because Battlefield 3 only uses 4 cores, to be more specific 4 threads. So if you´d run that game on this kind of CPU, at it´s standard configuration, you´ll experience rather bad performance. Why? That´s because the game will only utilize the first 4 cores of your CPU, meaning the first 2 modules. Remeber that two modules only have one FPU each, which are essential for good performance in video games. Not only does scheduling under Windows 7 slow the CPU cores down but also sharing of important resources.
However, there´s is a trick to counter this. If you happen to own a motherboard which has got a core-unlock feature you can use this to turn your AMD FX-8120/8150 into a true Quad-Core FX processor.
In the BIOS settings of my Gigabyte 990XA-UD3 it would look like this when all 8 cores are turned on.
Core 0 enabled
Core 1 enabled
Core 2 enabled
Core 3 enabled
Core 4 enabled
Core 5 enabled
Core 6 enabled
Core 7 enabled
Now in order to turn this CPU into a true Quad-Core, where none of the 4 cores will have to share resource, you´d have to configure the CPU like this:
Core 0 enabled <--- This one is actually always enabled. You can´t even disable it. At least not on my mobo.
Core 1 disabled
Core 2 enabled
Core 3 disabled
Core 4 enabled
Core 5 disabled
Core 6 enabled
Core 7 disabled
You will basically turn off / deactivate / disable the second core of each of the 4 available modules ending up with a Quad-Core where none of the 4 active cores will have share resources.
If you don´t beleive that this configuration works then take a good look at this forum:
http://www.xtremesystems.org/forums/showthread.php?275873-AMD-FX-quot-Bulldozer-quot-Review-%284%29-!exclusive!-Excuse-for-1-Threaded-Perf.
There you´ll see that this improves Quad-Core performance significantly. This should turn your AMD FX-8000 series CPUs into a more potent Quad-Core CPUs for gaming.
Now what´s interesting about this is that this test clearly shows / exposes the great weaknesses of the module-based architecture. And yes, I know that it´s a total waste to buy an FX-8120/8150 just to turn of 4 of its cores and use it as a Quad-Core. I just think that this would give those who already own one the oportunity to at least turn it into a true Quad-Core if they want to play a game with decent CPU performance.
One more thing. This configuration wouldn´t only turn it into a stronger Quad-Core it would also improve single-threaded performance.
I also believe that by using this configuration the CPU will consume less energy and therefore produce less heat. I cannot prove this though as I haven´t tested it myself (I don´t own any Bulldozer or Trinity CPU) and in the linked forum there are no test results on that matter.
If any of you guys have done this with their FX-8120/8150 CPU would you be so kind and tell me whether you could notice a decrease in power comsumption and heat output?
I know that it´s a long text. Please bare with.