Originally Posted by sumitlian
Look at this. This is after the latest patch.
( I excluded Turbo frequency for both architecture )
Here FX 6350 at 3.9 GHz is 21.8% faster in terms of frequency speed
than a 3.2 GHz Phenom II 1090T. Right ?
Ok we all know even a Piledriver core processes less IPC than a Thuban core. Right ?
So lets assume here at extreme condition that FX has 21.8% less IPC than phenom II. (I intentionally took even lower IPC than what people usually think.)So here we start speculation keeping in mind that 3.9 GHz FX IPC is equal to 3.2 GHz Phenom II in six threaded multithreading because AMD calls both CPUs as hexa core CPU. Ok ?
Phenom II X6 1090T at 3.2 GHz = 49 fps minimum
FX 6350 at 3.9 GHz = 34 fps minimum
You are saying FX's each core within a module can do 128 bit FP concurrently (I agree with both of you)
and each core at rated frequency (I don't agree).[Condition 1:]
Game is using 128 bit instructions.( Up to SSE4.2)
FX at 3.9 GHz should be definitely equal to Phenom II at 3.2 GHz. (Remember IPC is same)Q1. Why is FX drawing 44% less FPS than Phenom ?[condition 2]
Game is using 256 bit instructions( FMA / AVX).
Note: Phenom II doesn't natively support 256 bit instructions.
So theoretically Phenom II should do it in two cycles (two 128 bit cycles per core of Phenom II).
FX does support 256 bit instructions but unfortunately it does it in two cycles, so no FPU improvement over Phenom II (one 128 bit cycle by per core in a module)
So again both FX and Thuban become equal in 256 bit operations.Q2. Why is FX still giving 44% less minimum fps than Phenom ?
FX has much higher memory bandwidth because of improved memory controller, so CPU memory bandwidth should never be an issue here.
I respect you all, this has never been about picking on anyone. This is not my type. So please don't be rude to me and its Now your turn to try to convince me that each core is still concurrently running at rated speed.
Remember I believe each module runs at rated speed.
i think we're saying the same thing though in different ways. You think it's a core issue, structural problems with piledriver, i'm saying it's coding problems with BF4, that are hampering piledriver artificially. Unfortunately those numbers prove us both right and doesn't answer the question of which it is. Piledriver's ipc is roughly 15% slower then the 1100T, we know this to be true. on other gaming benches we often see the 6 core'd piledriver at the same clock speed as the 6 cored 1100T coming in at about 15% lower frame rates. AMD's own litterature backs this up as does plenty of testing.
yet in BF4 we're seeing a continuation of what we saw in earilier numbers. Piledriver punching WAY under it's weight class. My conclusion which is this is because BF4 is optimized for jaguar, and for some reason the claim that optimization actually handicaps piledriver remains. Your claims that it's based on floating point calculations is dubious at best. You're right... piledriver can, at times struggle with floating point math... particularly 256 bit operations. Piledriver can't handle 256bit floating point math operations efficiently. In this your correct. i still stand by my previous post where i stated everything else about your summery of piledriver was incorrect, misinformed or about bulldozer, not piledriver. most if not all of your claims about how piledriver behaves and clocks its cores was based on how bulldozer behaved. the vast majority of that info does not, and has not ever applied to piledriver.
Now if BF4 using a bunch of CPU power for floating point math (which makes no sense since gpus are the greatest floating point math compute units in existence, and can do it FAR more efficiently then a CPU can) and that floating point math is 256bit, then yes. i can see piledriver's structural issues being the problem. at the same side of the coin, that still
validates my point. that while BF4 might be amd optimised, it's optimised for jaguar and not piledriver, and the structure is so different as to be effectively harming piledriver in running this game.
in short we're talking past each other and actually in agreement on some level.. you see i'm still right even if you're right... but you have so much wrong about piledriver i doubt you're right about this.